7th Annual Brain Metastases Research and Emerging Therapies Conference
October 6 — October 7
In a retrospective series of 1345 patients with CPA lesions the common underlying diagnoses were VS (91.3%), meningiomas (3.1%), epidermoids (2.4%) and facial nerve schwannomas (1.2%). Other rare causes (2%) included lipomas, gliomas, dermoids, arachnoid cysts, hemangiomas, hemangioblastomas, medulloblastomas, chondrosarcomas, malignant teratomas and metastasis 1).
Isolated metastases to the CPA represent a diagnostic challenge to differentiate them from the more commonly occurring CPA lesions, particularly in the absence of metastatic disease 2).
In a small series of 14 patients with metastasis to the CPA, this was the initial presentation of the underlying malignancy in 4 (28%) 3).
Features suggestive of metastasis as opposed to schwannoma were acute onset, rapid progression of symptoms, associated seventh and/or eighth nerve deficits, bilateral involvement or systemic metastasis. Useful MRI findings included small and/or bilateral CPA enhancing lesions with relative isointensity to brain parenchyma on pre-contrast MRI and associated findings of multiple and/or bilateral cranial nerve and/or leptomeningeal lesions 4).
Ten patients were reviewed for the period between 2008 and 2015. The clinical and neuroimaging features, and treatment outcomes were analyzed retrospectively. The average period during primary diagnosis through the diagnosis of CPA metastases was 42.4 months. Among the 10 cases, the primary tumors and metastases were found simultaneously in 3 cases, the metastases after primary tumor removal were found in 5 cases, and the metastases after stereotaxic radiosurgery were found in 2 cases. Only 4 patients presented with the symptoms and signs associated with CPA involving, one with hearing loss, one presenting facial paralysis, one suffering from tinnitus and one case with dizziness. There were 2 cases with the miliary metastases and 8 cases with massive metastases. There existed 3 cases with single CPA metastases, whereas 7 cases with multiple metastatic foci. Among the 8 cases of massive metastatic foci, 6 tumors presented the solid features and the other 2 cases exhibited cystic and solid features. In this cohort of cases, 4 cases were involved in the bilateral and 6 cases presented unilateral metastatic foci. The three CPA metastases were removed in this group, 6 case performed with radiotherapy, and 5 cases received chemotherapy. In the current group 5 patients have been dead, 3 patients kept stable and 2 cases experienced improvement. In spite of seldom previous reports regarding the metastases from CNS tumors occurring in the CPA are existent, this rare form of the disease should be considered in future evaluation as a differential diagnosis 5).
A total of 174 cancer patients with inner ear-related symptoms such as vertigo, hearing loss, or tinnitus were seen at the university hospital from January 1994 to December 2000. All patients underwent a battery of audiologic and neurotologic tests. Magnetic resonance imaging was performed either when the clinical presentation suggested vertigo of central origin or when sensorineural hearing loss developed.
Magnetic resonance imaging confirmed tumors of the cerebellopontine angle in 6 (3%) of the 174 patients, including 3 men and 3 women. Their ages ranged from 46 to 80 years (mean 62 years). The final diagnoses were breast cancer with cerebellopontine angle metastasis (1), breast cancer with cerebellopontine angle epidermoid cyst (1), colon cancer with cerebellopontine angle metastasis (1), colon cancer with acoustic neuroma (1), nasopharyngeal carcinoma with cerebellopontine angle metastasis (1), and nasopharyngeal carcinoma with cerebellopontine angle benign tumor (1).
When a cerebellopontine angle tumor is discovered in a cancer patient, metastatic cancer should be suspected when the tumor presents with deficits of the VIIth and VIIIth cranial nerves of rapid progression or bilateral involvement, or extracranial systemic metastasis. Laboratory examinations such as cytologic study of the cerebrospinal fluid and serologic study can assist in the diagnosis 6).
A 61-year-old man, who visited an otorhinolaryngology clinic with complaints of rapidly progressing bilateral hearing impairment and facial palsy. The patient was referred to our hospital because tumorous lesions were suspected in the bilateral cerebellopontine angles on brain magnetic resonance imaging. Regarding tumor markers, the patient’s cancer antigen 19-9 and carcinoembryonic antigen levels were high, which suggested metastasis. However, no abnormal findings other than abdominal lymph node enlargement were detected on whole-body examination, and no primary lesion was identified. The tumor in the right cerebellopontine angle was excised using the lateral suboccipital approach and subjected to pathological examination. It was diagnosed as an adenocarcinoma; thus, both lesions were considered brain metastases from a malignant abdominal tumor, and radiochemotherapy was administered to the patient. Unfortunately, the patient died after 89 days of treatment, and a pathological autopsy revealed that the primary lesion was a common bile duct tumor. No dural metastasis was noted in the brain or spinal cord; however, tumors were detected in the epiarachnoid space during surgery. Metastasis to the bilateral cerebellopontine angles occurred in the same period, which was indicative of ascending metastasis through the vertebrobasilar artery. Hence, we suggest that progressive bilateral hearing impairment and facial palsy were a consequence of brain tumors that had metastasized bilaterally to the cerebellopontine angles 7).
A 63-year-old male who underwent surgical resection of a poorly differentiated small cell carcinoma, likely from a small intestinal primary tumor that metastasized to the cerebellopontine angle (CPA). A 63-year-old male presented with mild left facial paralysis, hearing loss, and balance instability. MRI revealed a 15 mm mass in the left CPA involving the internal auditory canal consistent with a vestibular schwannoma. Preoperative MRI eight weeks later demonstrated marked enlargement to 35 mm. The patient underwent a suboccipital craniectomy and the mass was grossly different visually and in consistency from a standard vestibular schwannoma. The final pathology revealed a poorly differentiated small cell carcinoma. Postoperative PET scan identified avid uptake in the small intestine suggestive of either a small intestinal primary tumor or additional metastatic disease. The patient underwent whole brain radiation therapy and chemotherapy and at last follow-up demonstrated improvement in his symptoms. Surgical resection and radiotherapy are potential treatment options to improve survival in patients diagnosed with NET brain metastases. We present the first documented case of skull base metastasis of a poorly differentiated small cell carcinoma involving the CPA 8).
This is the first formal case report of internal auditory canal and cerebellopontine angle metastasis from infiltrative ductal carcinoma of the breast. Only three previous cases have been reported of isolated metastasis in the cerebellopontine angle and internal auditory canal from breast cancer. Currently, no therapeutic guidelines for isolated metastasis from breast cancer in this location exist. We report a case and review the current literature in order to help characterize the clinicopathologic features and management. A 72-year-old female with a 5-year history of left infiltrative ductal carcinoma of the breast reported progressive left-sided facial palsy and ipsilateral hearing loss accompanied by the development of tinnitus and unsteadiness during the previous 3 months. MRI identified a lesion in the cerebellopontine angle and internal auditory canal. The lesion was completely excised via a retrosigmoidal approach and adjuvant radiotherapy was used subsequently. The patient remains well 18 months after treatment, with no evidence of recurrence on repeat MRI. The rapid evolution of symptoms involving the Vth, VIIth or VIIIth cranial nerve, or multiple cranial nerves, is suggestive of a malignant lesion of the cerebellopontine angle and/or internal auditory canal. A previous history of neoplasm is important due to the possibility of a metastasis. Cerebellopontine angle metastasis can be found many years after the initial diagnosis of breast neoplasm. Surgery and adjuvant radiotherapy seems to be a good choice for the treatment of patients with this specific type of metastasis9).
Bilateral cerebellopontine angle (CPA) tumors identified on MRI are considered bilateral acoustic neuromas, the definitive diagnostic criterion of neurofibromatosis 2 (NF-2). We report the case of a 67-year-old man with progressive bilateral hearing loss, vertigo, and imbalance. MRI revealed bilateral enhancing CPA lesions, which were suggestive of acoustic neuromas and a diagnosis of NF-2. However, autopsy showed metastatic adenocarcinoma of the lung. Therefore, metastatic carcinoma to the CPA can mimic bilateral acoustic neuromas; imaging studies alone may be insufficient to diagnose NF-2 10).
The primary aim of surgical treatment for falcotentorial meningiomas is gross total excision. The vital surrounding brain structures make this a complex task.
Several surgical approaches have been described to treat falcotentorial meningiomas. These include infratentorial supracerebellar approach, suboccipital approach, occipital transtentorial approach, and combined supratentorial and infratentorial approaches 1) 2) 3).
There are two main issues in treating falcotentorial meningiomas. One is selecting the surgical approach, which includes design of the bone flap. The other main issue is whether main venous structures will be sacrificed for a radical tumor resection.
In all of the cases, Hong et al. tried to make an adequately sized bone flap, even when the tumor was quite large. Some authors have insisted on performing wide craniotomies for large falcotentorial meningiomas 4).
Quiñones-Hinojosa, et al. 5) described a bilateral occipital transtentorial/transfalcine approach for large falcotentorial meningiomas. They ligated and cut the transverse sinus after checking the patency of the occluded sinus, and used permanent aneurysmal clips to ligate the vein of Galenwhen the straight sinus was occluded. The area above and below the tentorium can provide wide exposure and reduce occipital lobe retraction during prolonged operation times. Moreover, this approach may allow surgeons some form of intraoperative flexibility in terms of their surgical plan.
Hong et al. do not suggest routine application of wide craniotomies, such as the combined supratentorial and infratentorial approach. This is because wide craniotomies may increase the total amount of bleeding, prolong the operation time, and increase the risk of cerebral cortex injury. Moreover, it is possible to completely remove huge falcotentorial meningiomas without neurological deficit via relatively small craniotomies.
A catheter for CSF drainage was inserted into the ventricle or cisternal space through the safest area in each patient. They also designed small craniotomies through which the possible access area covered the entire tumor territory. Thus, if a CSF drain is possible, then appropriately designed small craniotomies are sufficient to achieve complete tumor resection without cortex injury 6).
Every venous structure should be preserved even if they seem to lack significant function. This will help prevent complications associated with delayed lobar parenchymal hemorrhage that can be attributed to venous infarction.
In conclusion, surgical approaches should be tailored to each patient according to the origin and direction of tumor growth, feeding arteries, and the surrounding venous drainage system.
Hong et al. found that a relatively small craniotomy was sufficient to completely remove each tumor. Moreover, they found that the most important factors for avoiding surgical complications were to preserve vital deep neurovascular structures, as well as flow through the venous sinuses.
The results showed that falcotentorial meningiomas could be cured via single-stage operations without complications by applying careful perioperative planning and a delicate microsurgical technique 11).
In this operative video, the authors demonstrate an illustrative step-by-step technique for endoscopic-assisted microsurgical resection of a falcotentorial meningioma using the posterior interhemispheric retrocallosal transfalcine approach for a superiorly positioned falcotentorial meningioma. The surgical nuances are discussed, including the surgical anatomy, gravity-assisted interhemispheric approach in the lateral position, retrocallosal dissection, transfalcine exposure, tumor removal, and preservation of the vein of Galen complex. In summary, the posterior interhemispheric retrocallosal transfalcine approach is a useful surgical strategy for select superiorly positioned falcotentorial meningiomas.
From 2001 to 2005, 9 patients underwent operation for meningiomas arising from the falcotentorial junction, with some extending to and/or invading the torcula. All patients were assessed preoperatively with magnetic resonance neuroimaging and cerebral angiography. Furthermore, preoperative embolization was attempted in all cases. A supratentorial/infratentorial torcular craniotomy technique was used in all but 1 of these cases.
The average dimensions of the falcotentorial meningiomas were 5.1 x 4.4 x 4.2 cm. The angiograms revealed that these tumors were fed by branches of the internal carotid artery, choroidal arteries, branches of the meningohypophyseal trunk, and branches of the posterior cerebral artery. Preoperative embolization was achieved in only 2 patients. Five patients had gross total resection (Simpson grade 1), and 4 had subtotal resection (Simpson grade 4). Two of the tumors (22%) recurred during a mean follow-up period of 49 months (range, 17-88 months). The most common complication after surgery was cortical blindness, but all postoperative visual deficits had fully recovered at the last follow-up evaluation within several months.
An excellent outcome can be expected with detailed preoperative neuroimaging and knowledge of the nuances of the surgical technique that we describe in detail in the article 12).
Goto et al. evaluated their surgical experience over 20 years with 14 treated falcotentorial meningiomas.
In the past 20 years, 14 patients with falcotentorial junction meningiomas were surgically treated. There were seven men and seven women, whose ages ranged from 34 to 79 years. On the basis of neuroimaging studies, the authors analyzed the influence of the anatomical relationship of the tumor to the vein of Galen, patency of the vein of Galen, tumor size, and the signal intensities on the magnetic resonance images to determine possible difficulties that might be encountered during surgery and to prognosticate the outcome of surgery. Depending on the relationship with the vein of Galen, tumors were labeled as either a superior or an inferior type. All tumors were resected via an occipital transtentorial approach. The surgical outcome in eight patients was excellent; in the remaining six patients, it was fair. Of the prognostic factors, tumor location especially seemed to be the most important (p < 0.01, Fisher exact test). The outcome associated with the inferior type of tumor was significantly less optimal probably due to the relationship to the deep veins and the brainstem. In this series, the occlusion of deep veins did not significantly influence outcome.
Classification of the tumor location by preoperative neuroimaging studies can be helpful in estimating the surgical difficulty that might be encountered in treating the falcotentorial junction meningioma 13).
Meningiomas arising from the falcotentorial junction are rare. As a result, their clinical presentation and surgical management are not well described. During the past 3 years, the authors have treated six patients with falcotentorial meningiomas.
Most patients presented with symptoms related to raised intracranial pressure, including headaches, papilledema, and visual and gait disturbances. Magnetic resonance imaging revealed a smooth, oval, or round mass, which was typically homogeneously enhancing. Angiography was useful in evaluating arterial supply for embolization, when possible, and determining the status of venous collateral supply and sinus patency. The authors detail the surgical technique used in all six patients. Postoperatively, patients experienced transient cortical blindness, which in all cases spontaneously resolved during the course of several days to weeks. They provide a comprehensive description of the presentation and surgical management of falcotentorial meningiomas.
An excellent outcome can be expected when surgery is predicated on detailed preoperative neuroimaging and knowledge of the nuances of the surgical technique 14).
Okami et al. present four surgical cases. An occipital transtentorial approach was used in three cases, and a combined midline occipital and suboccipital approach in one case. Total tumour excision was impossible in two cases because of engulfing deep venous structures including the great vein of Galen. Postoperative Gamma knife radiosurgery was performed in these two cases. On the other hand, a posteriorly located tumour was relatively easy to remove, and macroscopic total removal was accomplished. In conclusion, precise microvascular anatomical knowledge is indispensable to satisfactorily excise meningiomas in the falcotentorial area without significant morbidity 15).
Asari et al. describe the clinical features, neuroimaging studies, and results of surgical treatment of meningiomas of the falcotentorial junction and clarify the characteristics of this lesion based on a review of the literature and seven patients treated at their institution. The most common symptoms resulted from intracranial hypertension. Upward-gaze palsy appeared in only one patient. Computerized tomography (CT) showed no specific findings, but there was no evidence of edema around the tumor. Magnetic resonance (MR) imaging revealed a round, smooth-bordered mass with a peritumoral rim, without edema, and showing marked contrast enhancement. The multiplanar capability of MR imaging delineated the relationship between the tumor and adjacent structures better than did CT. Detailed knowledge of the vascular structures, especially evidence of occlusion of the galenic venous system and the development of collateral venous channels, is critical for successful surgery; stereoscopic cerebral angiography is necessary to achieve this aim. The seven patients described developed five types of collateral venous channels: through the basal vein of Rosenthal to the petrosal vein, through the veins on the medial surface of the parietal and occipital lobes to the superior sagittal sinus, through superficial anastomotic veins, through veins of the posterior fossa to the transverse or straight sinus, and through the falcian veins to the superior sagittal sinus. The first three types mainly developed after occlusion of the galenic system. The tumors were removed through the occipital transtentorial approach with a large window at the posterior part of the falx. A favorable prognosis for patients undergoing surgical treatment of falcotentorial junction meningiomas can be expected if detailed neuroimaging studies and microsurgical techniques are used 16).
The tumors were removed subtotally or totally via an occipital interhemispheric transtentorial approach and/or infratentorial supracerebellar approach. The postoperative courses were uneventful, and no neurological deficit was detected postoperatively. Pineal region tumors with a maximum diameter of 5 cm or larger should be operated on via a unilateral or bilateral occipital interhemispheric transtentorial approach, regardless of the angiographic findings, because this permits a wide operative field and can be followed, if necessary, by an infratentorial supracerebellar approach. Selection of the operative approach for a relatively small pineal region tumor should depend on the angiographic findings: downward displacement of the bilateral internal cerebral veins and the great vein of Galen indicates an occipital interhemispheric transtentorial approach, whereas upward displacement indicates an infratentorial supracerebellar approach 17).
One representative case of falcotentorial meningioma treated through an anterior interhemispheric transsplenial approach is also described. Among the interhemispheric approaches to the pineal region, the anterior interhemispheric transsplenial approach has several advantages. 1) There are few or no bridging veins at the level of the pericoronal suture. 2) The parietal and occipital lobes are not retracted, which reduces the chances of approach-related morbidity, especially in the dominant hemisphere. 3) The risk of damage to the deep venous structures is low because the tumor surface reached first is relatively vein free. 4) The internal cerebral veins can be manipulated and dissected away laterally through the anterior interhemispheric route but not via the posterior interhemispheric route. 5) Early control of medial posterior choroidal arteries is obtained. The anterior interhemispheric transsplenial approach provides a safe and effective surgical corridor for patients with supratentorial pineal region tumors that 1) extend superiorly, involve the splenium of the corpus callosum, and push the deep venous system in a posterosuperior or an anteroinferior direction; 2) are tentorial and displace the deep venous system inferiorly; or 3) originate from the splenium of the corpus callosum 18).
Kawashima et al. reported, in anatomic studies, a occipital transtentorial approach: the occipital bi-transtentorial/falcine approach, to treat such lesions. Gusmão et al. present a patient with a large falcotentorial meningioma, located bilaterally in the posterior incisural space. The occipital bi-transtentorial/falcine approach allowed an excellent surgical exposure and complete tumor removal with an excellent patient outcome 19).
It is a new pattern of neuronal tumour included in the World Health Organization Classification of Tumors of the Central Nervous System 2016, as a unique cytoarchitectural pattern of gangliocytoma.
There are fifteen reports in the literature to date. They are typically associated with late onset epilepsy.
Clinical, pathological and genetic data could indicate that MVNT aligns more with a malformative lesion than a true neoplasm with origin from a progenitor neuro-glial cell type showing aberrant maturation 2).
Dysembryoplastic neuroepithelial tumor – DNET can appear similar but usually is mostly cortical (rather than subcortical) often has bright FLAIR rim focal cortical dysplasia (Type II) high T2 signal deep to cortex is in the same location but is usually associated with a radial glial band (transmantle sign) and with thickened abnormal overlying cortex perivascular spaces location can be similar usually more elongated along vessel long axis fully attenuating on FLAIR 3).
MVNTs appear to be benign tumours with very indolent biological behaviour which can, if asymptomatic, be followed with imaging alone. In symptomatic patients (epileptic) surgical resection often controls seizures, with no tumour regrowth reported 4) 5) 6) 7).
Thom et al. present a series of ten cases and compare their pathological and genetic features to better characterised epilepsy associated malformations including focal cortical dysplasia type II (FCDII) and low-grade epilepsy associated tumours (LEAT). Clinical and neuroradiology data were reviewed and a broad immunohistochemistry panel was applied to explore neuronal and glial differentiation, interneuronal populations, mTOR pathway activation and neurodegenerative changes. Next generation sequencing was performed for targeted multi-gene analysis to identify mutations common to epilepsy lesions including FCDII and LEAT. All of the surgical cases in this series presented with seizures, and were located in the temporal lobe. There was a lack of any progressive changes on serial pre-operative MRI and a mean age at surgery of 45 years. The vacuolated cells of the lesion expressed mature neuronal markers (neurofilament/SMI32, MAP2, synaptophysin). Prominent labelling of the lesional cells for developmentally regulated proteins (OTX1, TBR1, SOX2, MAP1b, CD34, GFAPδ) and oligodendroglial lineage markers (OLIG2, SMI94) was observed. No mutations were detected in the mTOR pathway genes, BRAF, FGFR1 or MYB. Clinical, pathological and genetic data could indicate that MVNT aligns more with a malformative lesion than a true neoplasm with origin from a progenitor neuro-glial cell type showing aberrant maturation 8).
Nunes et al. report 33 cases of presumed multinodular and vacuolating neuronal tumor of the cerebrum that exhibit a remarkably similar pattern of imaging findings consisting of a subcortical cluster of nodular lesions located on the inner surface of an otherwise normal-appearing cortex, principally within the deep cortical ribbon and superficial subcortical white matter, which is hyperintense on FLAIR. Only 4 of the cases are biopsy-proven because most were asymptomatic and incidentally discovered. The remaining were followed for a minimum of 24 months (mean, 3 years) without interval change. They demonstrate that these are benign, nonaggressive lesions that do not require biopsy in asymptomatic patients and behave more like a malformative process than a true neoplasm 9).
Huse et al. report 10 cases of a non-neurocytic, purely neuronal tumor affecting adults. Situated in the cerebral hemispheres, with 7 of 10 confined to the temporal lobes, most presented with seizures as their principal clinical manifestations. On magnetic resosnance imaging (MRI), the tumors generally appeared solid and non-contrast enhancing with minimal diffuse infiltration, edema, or mass effect. Six examples demonstrated internal nodularity. Microscopically, the tumor cells were largely distributed into discrete and coalescent nodules exhibiting varying degrees of matrix vacuolization, principally within the deep cortical ribbon and superficial subcortical white matter. Populating elements ranged from morphologically ambiguous to recognizably neuronal, with only two cases manifesting overt ganglion cell cytology. In all cases, tumor cells exhibited widespread nuclear immunolabeling for the HuC/HuD neuronal antigens, although expression of other neuronal markers, including synaptophysin, neurofilament and chromogranin was variable to absent. Tumor cells also failed to express GFAP, p53, IDH1 R132H, or CD34, although CD34-labeling ramified neural elements were present in the adjoining cortex of seven cases. Molecular analysis in a subset of cases failed to reveal DNA copy number abnormalities or BRAF V600E mutation. Follow-up data indicate that this unusual neuronal lesion behaves in benign, World Health Organization (WHO) grade I fashion and is amenable to surgical control 10).
Fukushima et al. report a case of MNVT involving a 37-year-old man who presented with an epileptogenic, superficial solid lesion in the left parietal lobe. Histomorphology of the resected specimen was characterized by nodular lesions with vacuolation. Nodules comprised irregular proliferation of neuronal cells, which ranged from ganglion-like forms to those with indistinct lineage. Immunohistochemical analysis showed that the lesional cells stained positively for HuC/HuD, synaptophysin, and Olig2, and negatively for NeuN, neurofilament, chromogranin A, GFAP, CD34, IDH1(R132H), and BRAF(V600E). Eighteen months following surgery, the patient is well and without neurological deficits. MVNTs are distinctive tumors that should be differentiated from ganglion cell tumors, dysembryoplastic neuroepithelial tumors, and malformation of cortical development 11).
Bodi et al. report the findings in two cases with similar features, a surgical resection and the other an autopsy specimen.Case 1, a 34-year-old female, underwent surgical resection for a multinodular non-enhancing frontal white matter lesion causing intractable epilepsy. Case 2, presented with motor neurone disease (MND) at the age of 71 and MRI scanning revealed extensive multinodular non-enhancing white matter lesions in the temporal lobe. There was no history of epilepsy and post mortem histology confirmed MND.Macroscopically multiple small grey well-formed, discrete and coalescent nodules were seen in the deep cortex and subcortical white matter. On histology, mature-looking neurons with large cytoplasmic vacuoles were distributed in a fibrillary background, where vacuoles were also noted. In the resected tumour scattered oligodendroglia-like cells were present. No ganglion cells were seen. The vacuolated cells exhibited immunopositivity for synaptophysin, HuC/HuD and p62 but were negative for NeuN, neurofilament, GFAP, IDH1, nestin and CD34. Electron microscopy showed non-membrane bound cytoplasmic vacuoles in the neurons and in some neuronal processes. The seizures recurred in Case 1.Some clinicopathological features of this lesion suggest a possible relationship with dysembryoplastic neuroepithelial tumour (DNT) although the morphological features are not typical of DNT. Case 2 demonstrates that MVNT may remain asymptomatic 12).
The development of cystic brain metastases remains a relatively rare occurrence.
Metastatic brain tumors are normally composed of cystic components, however, the reasons for the cyst formation have not been clearly investigated 1). Stem 2) reported that the brain cyst fluid protein always presents in the inflammatory exudates. Cumings 3) also reported that the cyst fluid formation may be correlated with the tumor degeneration. Gardner et al 4) found that fluid accumulating in brain tumors runs in the normal drainage route, since there are no lymphatic vessels in the tumors.
Gamma knife radiosurgery (GKRS) is occasionally a useful tool for maintaining good brain status in patients with brain metastases (METs). Conversely, Ishikawa et al. experienced patients with delayed cyst formation (DCF) several years after GKRS, a complication not previously reported 5).
The main challenge in discrimination between intracranial cystic lesions is to differentiate benign inflammatory cystic lesions (as cerebral abscess) from malignant cystic lesions (as cystic metastases and cystic glioma) which have totally different management.
The most common tumors are, hemangioblastoma, pilocytic astrocytoma, ganglioglioma, pleomorphic xanthoastrocytoma, tanycytic ependymoma, intraparenchymal schwannoma, desmoplastic infantile ganglioglioma.
Cystic meningioma is a rare form of intracranial meningioma. Meningiomas are typically solid tumors but may rarely have cystic components. The diagnosis of cystic meningioma is clinically challenging as the finding of multiple intra-axial tumors, including metastatic tumors, is relatively common. We report a case of cystic meningioma initially diagnosed as a metastatic tumor from a recurrence of acute lymphoid leukemia. However, postoperative histopathological examination demonstrated an atypical meningioma 6).
In a review, Kim et al. describe the characteristics of cystic brain metastasis and evaluate the combined use of stereotactic aspiration and radiosurgery in treating large cystic brain metastasis. The results of several studies show that stereotactic radiosurgery produces comparable local tumor control and survival rates as other surgery protocols. When the size of the tumor interferes with radiosurgery, stereotactic aspiration of the metastasis should be considered to reduce the target volume as well as decreasing the chance of radiation induced necrosis and providing symptomatic relief from mass effect. The combined use of stereotactic aspiration and radiosurgery has strong implications in improving patient outcomes 7).
Between December 2007 and February 2015, 38 consecutive patients with 40 cystic metastases underwent Ommaya reservoir implantation at our institution. The patient characteristics, treatment parameters, and all available clinical and neuroimaging follow-ups were analyzed retrospectively.
The rate of volume reduction was significantly related to the location of the tube tip inside the cyst. By placing the tip at or near the center, 58.7% reduction was achieved, whereas reduction of 42.6% and 7.7% occurred with deep and shallow tip placement, respectively (p=0.011). Although there was no additional surgery in the center placement group, additional surgeries were performed in 5 out of the 23 deep and shallow cases due to inadequate volume reduction. No other factors were correlated with successful volume reduction.
For adequate volume reduction using the Ommaya reservoir in the treatment of cystic brain metastases prior to stereotactic radiosurgery, the tip of the reservoir tube should be placed at the center of the cyst 8).
Lee et al. retrospectively reviewed the clinical, radiological, and dosimetry data of 37 cystic brain metastases of 28 patients who were treated with GKRS. Cyst drainage was performed in 8 large lesions before GKRS to decrease the target volume. The mean target volume was 4.8 (range, 0.3-15.8) cc at the time of GKRS, and the mean prescription dose was 16.6 (range, 13-22) Gy.
The actuarial median survival time was 17.7 ± 10.2 months, and the primary tumor status was a significant prognostic factor for survival. The actuarial local tumor control rate at 6 and 12 months was 93.1 and 82.3%, respectively. Among the various factors, only prescription dose (>15 Gy) was a significant factor related to local tumor control after multivariate analysis (p = 0.049). Cyst volume or cyst/total tumor volume ratio did not influence local control after GKRS, when the target volume was reduced to about 15 cc after cyst drainage.
According to this results, they suggest that stereotactic radiosurgery should be considered as one of the treatment options for cystic brain metastases, when large tumor volume can be reduced by surgical drainage before radiosurgery, especially for patients with a controlled primary tumor 9).
A study involved 48 patients who were diagnosed with cystic metastatic brain tumors between January 2008 and December 2012 in the Department of Neurosurgery of Nanfang Hospital Southern Medical University (Guangzhou, China). Every patient underwent Leksell stereotactic frame, 1.5T magnetic resonance imaging (MRI)-guided stereotactic cyst aspiration and Leksell GKRS. Subsequent to the therapy, MRI was performed every 3 months. The results indicated that 48 cases were followed up for 24-72 months, with a mean follow-up duration of 36.2 months. Following treatment, 44 patients (91.7%) exhibited tumor control and 4 patients (8.3%) experienced progression of the local tumor. During this period, 35 patients (72.9%) succumbed, but only 2 (4.2%) of these succumbed to the brain metastases. The total local control rate was 91.7% and the median overall survival time of all patients was 19.5 months. The 1-year overall survival rate was 70.8% and the 2-year overall survival rate was 26.2%. In conclusion, these results indicated that the method of stereotactic cyst aspiration combined with GKRS was safe and effective for patients with large cystic brain metastases. This method is effective for patients whose condition is too weak for general anesthesia and in whom the tumors are positioned at eloquent areas. This method enables patients to avoid a craniotomy, and provides a good tumor control rate, survival time and quality of life 10).
Between February 2005 and March 2012, a total of 24 patients underwent GKR after cyst aspiration for 29 cystic metastatic brain tumors. The median age was 60 years (range, 18-81). The number of male patients was 18 and that of female patients 6. Most of the patients were in class II (87.5%) based on the data of the Radiation Therapy Oncology Group using recursive partitioning analysis. We analyzed the changes in tumor volume, the local control rate, intracranial progression-free survival (PFS) and overall survival (OS).
Before aspiration, the mean total tumor volume was 32.7 cm(3) (range, 12.1-103.3) and cystic volume was 18.6 cm(3) (range, 8-72.3). The mean duration of cyst drainage was 1 day (range, 1-2). The mean amount of aspiration was 16.8 cm(3) (range, 6-67.4). After aspiration, the total mean volume was 12.4 cm(3) (range, 3.7-38.1) and cystic volume was 2.0 cm(3) (range, 0.1-9.5). The nature of the cyst was serous in 18, serous and hemorrhagic in 3, and serous and necrotic in 8. The median prescription dose was 16 Gy (range, 14-20). There was no treatment-related complication. The local control rate was 58.6% (17/29). The median survival to local recurrence was 6.0 (±1.42) months. During the follow-up period, an Ommaya reservoir was placed in 3 patients. Insertion of an Ommaya reservoir and whole-brain radiotherapy (WBRT) or GKR were done in 2 patients, WBRT in 2, GKR in 1 and operation in 1. The median intracranial PFS and OS after intracranial metastasis was 5.2 (±0.42) and 6.8 (±0.38) months.
Cyst aspiration and GKR were feasible and safe but not very efficient, which could be an alternative option for large cystic metastases in patients who could not expect longer survival time 11).
Ebinu et al. reviewed a prospectively maintained database of brain metastases patients treated between 2006 and 2010. All lesions with a cystic component were identified, and volumetric analysis was done to measure percentage of cystic volume on day of treatment and consecutive follow-up MRI scans. Clinical, radiologic, and dosimetry parameters were reviewed to establish the overall response of cystic metastases to GKRS as well as identify potential predictive factors of response.
A total of 111 lesions in 73 patients were analyzed; 57% of lesions received prior whole-brain radiation therapy (WBRT). Lung carcinoma was the primary cancer in 51% of patients, 10% breast, 10% colorectal, 4% melanoma, and 26% other. Fifty-seven percent of the patients were recursive partitioning analysis class 1, the remainder class 2. Mean target volume was 3.3 mL (range, 0.1-23 mL). Median prescription dose was 21 Gy (range, 15-24 Gy). Local control rates were 91%, 63%, and 37% at 6, 12, and 18 months, respectively. Local control was improved in lung primary and worse in patients with prior WBRT (univariate). Only lung primary predicted local control in multivariate analysis, whereas age and tumor volume did not. Lesions with a large cystic component did not show a poorer response compared with those with a small cystic component.
This study supports the use of GKRS in the management of nonsurgical cystic metastases, despite a traditionally perceived poorer response. Our local control rates are comparable to a matched cohort of noncystic brain metastases, and therefore the presence of a large cystic component should not deter the use of GKRS. Predictors of response included tumor subtype. Prior WBRT decreased effectiveness of SRS for local control rates 12).
Between 2005 and 2010, 25 cystic metastases in 25 patients were treated at Dokkyo Medical University. The patients first underwent MRI and stereotactic aspiration of the cyst while stationary in a Leksell stereotactic frame; immediately afterward, the patients underwent a second MR imaging session and Gamma Knife treatment. Tumor volume reduction, tumor control rate, and overall survival were examined.
Tumor volume, including the cystic component, decreased from 8.0-64.2 cm(3) (mean 20.3 cm(3)) to 3.0-36.2 cm(3) (mean 10.3 cm(3)) following aspiration, and the volume of 24 of 25 lesions decreased to less than 16.6 cm(3), which is equivalent to the volume of a 3.16-cm sphere. At least 20 Gy was delivered to the entire lesion in 24 of 25 cases. Good tumor control was obtained in 16 of 21 cases that could be evaluated during a median follow-up period of 11 months (range 1-27 months); however, reaccumulation of cyst contents was observed in 2 patients who required Ommaya reservoir placement.
The 1-day aspiration plus GKS procedure is an effective and time-efficient treatment for large cystic brain metastases 13).
Hydrofiber dressing is a sodium carboxymethylcellulose hydrocolloid polymer with high fluid-absorptive capacity. This material was originally used as a dressing for exudative wounds. Hydrofiber dressing was used for 8 patients with cystic-type metastatic brain tumor. Tumor removal was performed after hydrofiber dressing was inserted into the cyst cavity to transform the tumor into a solid-type tumor.
Transformation of cystic-type metastatic brain tumors into smaller solid-type tumors using hydrofiber dressing facilitated en bloc resection of tumor. The dressing also absorbed residual cyst fluid and was thus also effective in preventing intraoperative dissemination of tumor cells. This approach enabled ideal en bloc resection in all patients. There were no adverse events.
These findings suggest hydrofiber dressing may be useful in surgery for cystic-type metastatic brain tumors 14).
Between January 2001 and November 2005, 680 consecutive patients with brain metastases underwent GKS at our hospital, 30 of whom were included in this study (18 males and 12 females, mean age 60.6 +/- 11 years, range 38-75 years). Inclusion criteria were: 1) no prior whole-brain radiation therapy or resection procedure; 2) a maximum of 4 lesions on preoperative MR imaging; 3) at least 1 cystic lesion; 4) a Karnofsky Performance Scale score >or= 70; and 5) histological diagnosis of a malignant tumor.
Non-small cell lung carcinoma was the primary cancer in most patients (19 patients [63.3%]). A single metastasis was present in 13 patients (43.3%). There was a total of 81 tumors, 33 of which were cystic. Ten patients (33.3%) were in recursive partitioning analysis Class I, and 20 (66.6%) were in Class II. Before drainage the mean tumor volume was 21.8 ml (range 3.8-68 ml); before GKS the mean tumor volume was 10.1 ml (range 1.2-32 ml). The mean prescription dose to the tumor margin was 19.5 Gy (range 12-25 Gy). Overall median patient survival was 15 months. The 1- and 2-year survival rates were 54.7% (95% confidence interval 45.3-64.1%) and 34.2% (95% confidence interval 23.1-45.3%). Local tumor control was achieved in 91.3% of the patients.
The results of this study support the use of a multiple stereotactic approach in cases of multiple and cystic brain metastasis 15).
A study describes the first case of histopathologically-confirmed brainstem metastasis originating from lung adenosquamous carcinoma, and discusses the outcomes of treatment by stereotactic aspiration combined with gamma knife radiosurgery (GKRS). A 59-year-old female presented with a cystic mass (15×12×13 mm; volume, 1.3 cm3) located in the pons, two years following surgical treatment for adenosquamous carcinoma of the lung. The patient received initial GKRS for the lesion in the pons with a total dose of 54.0 Gy, however, the volume of the mass subsequently increased to 3.9 cm3 over a period of three months. Computed tomography-guided stereotactic biopsy and aspiration of the intratumoral cyst were performed, yielding 2.0 cm3 of yellow-white fluid. Histology confirmed the diagnosis of adenosquamous carcinoma. Aspiration provided immediate symptomatic relief, and was followed one week later by repeat GKRS with a dose of 12.0 Gy. The patient survived for 12 months following the repeat GKRS; however, later succumbed to the disease after lapsing into a two-week coma. The findings of this case suggest that stereotactic aspiration of cysts may improve the effects of GKRS for the treatment of cystic brainstem metastasis; the decrease in tumor volume allowed a higher radiation dose to be administered with a lower risk of radiation-induced side effects. Therefore, stereotactic aspiration combined with GKRS may be an effective treatment for brainstem metastasis originating from adenosquamous carcinoma 16).
A 71-year-old man who was admitted to the emergency department after an episode of loss of consciousness. On neurological examination a left hemiparesis was observed. The patient’s previous history entailed a total cystectomy and radical prostatectomy 7 months ago because of a transitional cell carcinoma (TCC) of the urinary bladder. Brain imaging work-up revealed a cystic lesion with perifocal edema in the right frontal lobe. The patient was operated and the histological diagnosis was consistent with a metastatic carcinoma, with morphological, histochemical and immunohistochemical features comparable to those of the primary tumor. Postoperative the patient was in excellent neurological state and received complementary chemotherapy and total brain irradiation. Additional imaging and laboratory examinations excluded other metastatic lesion. The patient died 18 months later due to systemic disease. Although intracranial metastases from TCC of urinary bladder have a low incidence, in follow-up examinations any alterations in neurological status in these patients should be thoroughly evaluated 17).
Cystic brain metastases from small-cell lung carcinomas are exceedingly rare and neurosurgical operations are not suitable for those cases considering invisible micrometastases. A 34-year-old female patient presented with small-cell lung carcinoma that metastasized to the brain as a solitary cyst with a thin wall 24 months after a good partial response to initial chemoradiotherapy. The brain mass volume and the main symptom of left hemiplegia, which made the Karnofsky performance status (KPS) fall to 30%, did not respond to whole brain irradiation. Therefore, an Ommaya reservoir was inserted, which dramatically improved the KPS to 70%. This minimally invasive surgical strategy is suitable even for patients with a poorer KPS bearing cystic brain metastases 18).
In atypical meningiomas bone involvement and large meningioma peritumoral edema are associated with increased tumor progression.
Intracranial atypical meningiomas
Approximately 15-20% of meningiomas are atypical, meaning that the tumor cells do not appear typical or normal. Atypical meningiomas are neither malignant (cancerous) nor benign, but may become malignant.
The treatment of atypical meningioma remains controversial and under-investigated in prospective studies. The roles of surgery, radiation therapy, radiosurgery, and chemotherapy have been incompletely delineated. This has left physicians to decipher how they should treat patients on a case-by-case basis.
In a study, Sun et al. review the English-language literature on the management and clinical outcomes using the WHO 2000/2007 grading criteria. Twenty-two studies for AMs were examined in detail. The authors examined clinical decision points using the literature and concepts from evidence-based medicine. Acknowledging the retrospective nature of the studies, the authors did find evidence for the following clinical strategies:
1) maximal safe resection
2) active surveillance after gross-total resection
3) adjuvant radiation therapy after subtotal resection of AM, especially in the absence of putative radio resistant features 1).
Atypical meningiomas are increasingly irradiated, even after complete or near-complete microsurgical resection despite data that suggests that close observation remains reasonable in the setting of aggressive microsurgical resection.
Conformal, high dose radiotherapy resulted in significant improvement of local control for atypical and malignant meningiomas. Increased local control resulted also in improved rates of survival for patients with malignant meningioma 2).
Adjuvant radiation therapy or external beam radiation therapy (EBRT) improved local control after stereotactic radiosurgery STR but only for tumors without spontaneous necrosis. Spontaneous necrosis may aid in decisions to administer adjuvant SRS or EBRT after STR of AMs 3).
Necrosis may be a negative predictor of radiation response regardless of radiation timing or modality 4).
Grade II atypical meningiomas tend to recur and grow faster.
Retrospective series supports the observation that postoperative radiotherapy likely results in lower recurrence rates of gross totally resected atypical meningiomas.
Patients older than 55 years and those with mitoses noted during pathological examination had a significant risk of recurrence after GTR; for these patients, postoperative radiotherapy is recommended 5).
After GTR without postoperative radiation, AMs have a high recurrence rate. Most recurrences occurred within 5 years after resection. Recurrences caused numerous reoperations per patient and shortened survival 6).
A multicenter prospective trial will ultimately be needed to fully define the role of radiotherapy in managing gross totally resected atypical meningiomas 7).
Study limitations, including inadequate statistical power, may underlie the studies’ inability to demonstrate a statistically significant benefit for adjuvant radiotherapy in AM. Because these tumors preferentially recur within 5 years of surgical resection, future studies should define whether early adjuvant therapy should become part of the standard treatment paradigm for completely excised tumors 8).
Brain invasion and high mitotic rates may predict recurrence. After gross total resection (GTR) of AMs, EBRT appears not to affect progression free survival and overall survival, suggesting that observation rather than EBRT may be indicated after GTR 9).
The rarity and the inconsistent criteria for defining atypical meningioma prior to the WHO 2007 classification made its management and prognostic factors poorly understood. Only few articles have addressed the survival rates of WHO-classified atypical meningiomas. The small number or the disproportionate representation of irradiated patients was a weakness for these articles.
The most important prognostic factor in determining recurrence was Simpson grading. There was no statistically significant impact of adjuvant radiotherapy on the recurrence of atypical meningiomas. Metaanalysis for the existing literature is needed 10).
The National Cancer Database was used to identify 2515 patients who were diagnosed with AM between 2009 and 2012 and underwent STR or GTR with or without adjuvant RT. Propensity score matching was first applied to balance covariates including age, year of diagnosis, sex, race, histology, and tumor size in STR or GTR cohorts stratified by adjuvant RT status. Multivariate regression according to the Cox proportional hazards model and Kaplan-Meier survival plots with log-rank test were then used to evaluate OS difference associated with adjuvant RT.
GTR is associated with improved OS compared with STR. In the subgroup analysis, adjuvant RT in patients who underwent STR demonstrated significant association with improved OS compared with no adjuvant RT (adjusted hazard ratio [AHR] 0.590, P = .045); however, adjuvant RT is not associated with improved OS in patients who underwent GTR (AHR 1.093, P = .737).
Despite the lack of consensus on whether adjuvant RT reduces recurrence after surgical resection of AM, our study observed significantly improved OS with adjuvant RT compared with no adjuvant RT after STR 11).
Real-Peña et al published 27 patients with pathological diagnosis of atypical meningioma, and who had a minimum follow-up time of 6 months after diagnosis. Later prognostic factors (age <50years, male gender, bone involvement, peri-lesional swelling, tumour volume, location, Ki67/MIB-1) were evaluated after the stratification of patients undergoing complete resection in recurrencies and non-recurrencies. Univariate analysis was performed using Mann-Whitney test, χ(2) homogeneity test/Fisher exact test. Finally, multivariate analysis was performed using binary logistic regression to obtain the values for R(2) Nagelkerke and the Hosmer-Lemeshow to evaluate the goodness of fit.
The uni- and multivariate analysis showed no statistically significant differences between recurrent and non-recurrent subgroups of patients undergoing complete resection. It is noted in the results that for each year of age above 50 years, the risk of recurrence is decreased by 5.8%.
Although current prognostic factors may show an increased risk of recurrence once patients are stratified by the two most important factors (pathology and extent of resection), those factors are insufficient to predict the ultimate outcome of patients affected by this pathology 12)
Endo et al., reviewed 45 patients with atypical meningioma who underwent surgical intervention between January 2000 and December 2013. The mean age of the patients and mean follow-up period was 58.7 years and 81.0 months, respectively. Analyses included factors such as patient age, gender, location and size of tumor, extent of surgical resection (Simpson Grading System), and MIB-1 index (LI). Univariate analysis was used to detect prognostic factors associated with recurrence and survival.
The 5-year recurrence-free rate for all 45 patients was 58.4 %; 5- and 10-year survival rates were 83.2 % and 79.9 %, respectively. In univariate analyses, age >60 years, and MIB-1 LI correlated with disease recurrence, whereas age >60 years, subtotal surgical resection, MIB-1 LI, and indication for radiotherapy correlated with death. MIB-1 LI levels higher than 12.8 % and 19.7 % predicted recurrence and death, respectively. In our cohort, 26 patients received postoperative radiotherapy including conventional radiation (n = 21) or gamma knife radiosurgery (n = 5). Postoperative radiotherapy did not decrease recurrence rates in our cohort (p = 0.63). Six and two patients who died during the study period underwent conventional radiation and radiosurgery, respectively.
Age, male gender, extent of surgical resection, and higher MIB-1 LI influenced the outcome of atypical meningioma. In our cohort, postoperative radiotherapy failed to provide long-term tumor control. Following incomplete surgical resection of atypical meningioma in elderly patients, adjuvant postoperative radiotherapy may not be an ideal treatment option, particularly when MIB-1 LI is higher than 19.7 % 13).
44 WHO Grade II and 9 WHO Grade III meningiomas treated by CyberKnife for adjuvant or salvage therapy. Patient demographics, treatment parameters, local control, regional control, locoregional control, overall survival, radiation history, and complications were documented.
For WHO Grade II patients, recurrence occurred in 41%, with local, regional, and locoregional failure at 60 months recorded as 49%, 58% and 36%, respectively. For WHO Grade III patients, recurrence occurred in 66%, with local, regional, and locoregional failure at 12 months recorded as 57%, 100%, and 43%. The 60-month locoregional control rates for radiation naïve and experienced patients were 48% and 0% (p = 0.14), respectively. Overall, 7 of 44 Grade II patients and 8 of 9 Grade III patients had died at last follow-up. The 60-month and 12-month overall survival rates for Grade II and III meningioma were 87% and 50%, respectively. Serious complications occurred in 7.5% of patients.
SRS for adjuvant and salvage treatment of WHO Grade II meningioma by a hypofractionated plan is a viable treatment strategy with acceptable long-term tumor control, overall survival, and complication rates. Future work should contribute additional study toward the radiation naïve and the local management of malignant meningioma 14).
A triple center case-note review of adults with newly-diagnosed atypical meningiomas between 2001 and 2010 was performed. Pathology diagnosis was made according to the World Health Organization classification in use at the time of surgery. Patients with multiple meningiomas, neurofibromatosis type 2 and radiation-induced meningiomas were excluded. Extent of resection was defined as gross total resection (GTR; Simpson Grade I-III) or subtotal resection (STR; Simpson Grade IV-V). Survival analysis was performed using the Kaplan-Meier method. One hundred thirty-three patients were identified with a median age of 62years (range 22-86years) and median follow-up of 57.4months (range 0.1-152.2months). Tumors were mostly located in the convexity (50.4%) or falcine/parasagittal regions (27.1%). GTR (achieved in 85%) was associated with longer progression free survival (PFS) (5year PFS 81.2% versus 40.08%, log-rank=11.117, p=0.001) but not overall survival (OS) (5year OS 76.6% versus 39.7%, log-rank=3.652, p=0.056). Following GTR, early adjuvant radiotherapy was administered to 28.3% of patients and did not influence OS (5year OS 77.0% versus 75.7%, log-rank=0.075, p=0.784) or PFS (5year PFS 82.0% versus 79.3%, log-rank=0.059, p=0.808). Although extent of resection emerged as an important prognostic variable, early adjuvant radiotherapy did not influence outcome following GTR of atypical meningiomas. Prospective randomized controlled trials are planned 15).
Twenty-eight patients with skull base atypical meningiomas underwent microsurgical resection between June 2001 and November 2009. The clinical characteristics of the patients and meningiomas, the extent of surgical resection, and complications after treatment were retrospectively analyzed.
Thirteen patients (46.4%) had disease recurrence or progression during follow up time. The median time to disease progression was 64 months. The extent of the surgical resection significantly impacted prognosis. Gross total resection (GTR) of the tumor improved progression free survival (PFS) compared to subtotal resection (STR, p = 0.011). An older patient age at diagnosis also resulted in a worse outcome (p = 0.024). An MIB-1 index <8% also contributed to improved PFS (p = 0.031). None of the patients that underwent GTR and received adjuvant radiotherapy had tumors recur during follow up. STR with adjuvant radiotherapy tended to result in better local tumor control than STR alone (p = 0.074). Three of 28 patients (10.7%) developed complications after microsurgery. The GTR group had a higher rate of complications than those with STR. There were no late adverse effects after adjuvant radiotherapy during follow up.
For patients with skull base atypical meningiomas, GTR is desirable for longer PFS, unless radical excision is expected to lead to severe complications. Adjuvant radiation therapy is advisable to reduce tumor recurrence regardless of the extent of surgical resection. Age of disease onset and the MIB-1 index of the tumor were both independent prognostic factors of clinical outcome 16).
A retrospective analysis of the patients operated at the Clinic of Neurosurgery, Clinical Center of Serbia, Belgrade, between January 1st 1995 and December 31th 2006 was performed. In that period 88 lesions met the histological criteria for atypical (75) and anaplastic (13) meningioma. Postoperative radiotherapy was conducted in 63.6% of patients.
At a median follow-up of 67.4 months in all patients the overall survival was 68 months and five-year survival was about 54.5%. The median survival was 76 months with surgery and adjuvant radiotherapy and 40 months with surgery alone (Log rank=7.4; p=0.006). Recurrent disease occurred in 58 patients (65.9%). Median time between first surgery and tumor recurrence in patients undergoing radiotherapy was 51 months, while in non-irradiated group 24 months (Log rank=17.7; p˂0.001). Multivariate analysis identified as recurrence-predicting factors anaplastic histotype (hazard ratio=2,9; p=0,003) and postoperative radiotherapy (hazard ratio=4,5; p<0,001).
The addition of adjuvant radiotherapy to surgery for atypical and anaplastic meningiomas resulted in a clinically meaningful and statistically significant survival benefit 17).
Only two prior cases of benign dendritic melanocytes colonizing a meningioma have been reported.
Dehghan Harati et al. add a third case, describe clinicopathologic features shared by the three, and elucidate the risk factors for this very rare phenomenon. A 29 year-old Hispanic woman presented with headache and hydrocephalus. MRI showed a lobulated enhancing pineal region mass measuring 41 mm in greatest dimension. Subtotal resection of the mass demonstrated an atypical meningioma, WHO grade II, and the patient subsequently underwent radiotherapy. She presented 4 years later with diplopia, and MRI showed an enhancing extra-axial mass measuring 47 mm in greatest dimension and centered on the tentorial incisura. Subtotal resection showed a brain-invasive atypical meningioma with melanocytic colonization. The previous two cases in the literature were atypical meningiomas, one of which was also brain invasive. Atypical meningiomas may be at particular risk for melanocytic colonization as they upregulate molecules known to be chemoattractants for melanocytes. We detected c-Kit expression in a minority of the melanocytes as well as stem cell factor and basic fibroblast growth factor in the meningioma cells, suggesting that mechanisms implicated in normal melanocyte migration may be involved. In some cases, brain invasion with disruption of the leptomeningeal barrier may also facilitate migration from the subarachnoid space into the tumor. Whether there is low-level proliferation of the dendritic melanocytes is unclear. Given that all three patients were non-Caucasian, meningiomas in persons and/or brain regions with increased dendritic melanocytes may predispose to colonization. The age range spanned from 6 years old to 70 years old. All three patients were female. The role of gender and estrogen in the pathogenesis of this entity remains to be clarified. Whether melanocytic colonization may also occur in the more common Grade I meningiomas awaits identification of additional cases 18).
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This book describes in practical terms the endoscopic neurosurgery of the third ventricle and surrounding structures, emphasizing aspects of intraoperative endoscopic anatomy and ventricular approaches for main diseases, complemented by CT / MRI images. It is divided in two parts: Part I describes the evolution of the description of the ventricular system and traditional ventricular anatomy, besides the endoscopic neurosurgery evolution and current concepts, with images and schematic drawings, while Part II presents a collection of intraoperative images of endoscopic procedures, focusing in anatomy and main pathologies, complemented by schemes of the surgical approaches and CT / MRI images.
The Atlas of Endoscopic Neurosurgery of the Third Ventricle offers a revealing guide to the subject, addressing the needs of medical students, neuroscientists, neurologists and especially neurosurgeons.
Roberto Alexandre Dezena: MD from the Federal University of Triângulo Mineiro, Uberaba, Brazil (2003), completed his residency training in Neurosurgery at Santa Casa de Misericórdia de Ribeirão Preto, Brazil (2009), achieved his PhD in Neurosurgery at Ribeirão Preto Medical School of University of São Paulo, Brazil (2011), and his Postdoctoral Fellowship at Federal University of Triângulo Mineiro, Uberaba, Brazil (2014). In Brazil, is Full Member of Brazilian Society of Neurosurgery (SBN) and Brazilian Academy of Neurosurgery (ABNc). Internationally, is Fellow of World Federation of Neurosurgical Societes (WFNS), Active Member of both International Society for Pediatric Neurosurgery (ISPN) and International Federation of Neuroendoscopy (IFNE), and Full Member of both Latin American Federation of Neurosurgery Societes (FLANC) and Latin American Group of Studies in Neuroendoscopy (GLEN). Fellow of University of Tübingen, Germany, and University of Hiroshima, Japan. Currently is Chief of Division of Neurosurgery at Clinics Hospital, Neurosurgery Residency Director, and Professor of Postgraduate Program in Health Sciences and Postgraduate Program in Applied Biosciences, all in Federal University of Triângulo Mineiro, Uberaba, Brazil. Main neurosurgical areas in vascular and neuro-oncology microneurosurgery, endoscopic neurosurgery, pediatric neurosurgery, spinal surgery and neurotrauma. Main research areas in endoscopic neurosurgery, pediatric neurosurgery, neurotrauma, experimental cerebral ischemia and basic neurosciences. Editorial Board Member of International Journal of Anesthesiology Research (Phaps), Journal of Neurology and Stroke (Medcrave), EC Neurology (EC), and International Journal of Pediatrics and Children Health (Savvy). Reviewer of several online international scientific journals, highlighting World Neurosurgery (WFNS), Neurological Research (Maney) and Journal of Neurosurgical Sciences (Minerva).