Primary Intracranial Extra-Axial Anaplastic Ependymomas

Ventricular system-unrelated cerebellar ependymoma: A case report

BACKGROUND

An ependymoma is a glial tumor that usually occurs in or near the ventricle, close to the ependyma. It rarely occurs exclusively in the brain parenchyma without being associated with the ventricle.

CASE SUMMARY

Here, we report a rare case of a cerebellar ependymoma completely located in the brain parenchyma. A previously healthy 32-year-old female with a 1-month history of dizziness was admitted to our hospital. During hospitalization, magnetic resonance imaging of the brain revealed a space-occupying lesion measuring 57 mm × 41 mm × 51 mm in the right cerebellar hemisphere and inferior cerebellar vermis. The patient underwent surgical resection for the right cerebellar mass. Postoperative pathological examination revealed an ependymoma. At 1 year follow-up, the patient was doing well and showed no recurrence.

CONCLUSION

We conducted a literature review and summarized three theories regarding ependymomas located exclusively in the brain parenchyma, which are key to the diagnosis of intraparenchymal cerebellar ependymomas. Surgery and postoperative radiotherapy are the primary treatment options for ependymomas.

Supratentorial extra-axial anaplastic ependymoma: a rare case report

Introduction and importance

Ependymomas are central nervous system tumors arising from the ependymal lining of the ventricle and spinal cord. Supratentorial extra-axial ependymomas are very rare, most commonly affecting the pediatric population and rarely in adults.

Case presentation

The authors report a case of a 71-year-old female with a headache and blurred vision. An MRI scan revealed a lesion at the parafalcine region of the occipital lobe. A parieto-occipital craniotomy was performed. When the dura was opened during the operation, the extra-axially located, well-circumscribed, dirty yellow-white tumor dissected from the surrounding tissue was excised entirely by microdissection. Histopathological examination revealed supratentorial extra-axial anaplastic ependymoma. The patient received postoperative radiation therapy (54 Gray over 30 fractions). No recurrence of the tumor was observed during the 4-year follow-up.

Discussion

Supratentorial ependymomas at the extra-axial region are uncommon; extra-axial anaplastic ependymoma and meningiomas have similar radiological findings, such as a dural tail, subarachnoid plane, and diffuse enhancement after contrast injection. This close similarity might cause misdiagnoses. Total surgical resection was followed by adjuvant radiotherapy and close follow-up in the gold standard of the treatment.

Conclusion

The authors report a rare case of anaplastic ependymomas located at the extra-axial region. Anaplastic tumors are prone to recurrence despite total resection and radiation therapy; hence, a close follow-up is warranted.

A rare presentation of extra-axial supratentorial ependymoma with subdural hematoma mimicking a parasagittal meningioma

Introduction

Primary extra-axial ependymomas, though rare, the majority of such lesions are identified as WHO grade III ependymomas. These ependymomas may mimick a meningioma on radiological investigations which can be confirmed by histopathology.

Research Question

We show in this case report a rare presentation of extra-axial supratentorial ependymoma with concomitant subdural hematoma mimicking a parasagittal meningioma.

Material and Methods

A 59 years lady with no known comorbidities presented with weakness of right half of body and decreased speech for 2 days. She was aphasic. Contrast MRI brain revealed an extra-axial dural-based homogenously enhancing lesion in the left anterior 1/3^rd parasagittal area with left frontotemporoparietal chronic subdural hematoma. With a provisional diagnosis of meningioma, the patient was subjected to bifrontal open-book craniotomy with gross total excision of lesion with periosteal graft duraplasty and acrylic cranioplasty. Left sided frontotemporal subacute SDH with thin greenish yellow membrane was present. In post operative period, patient quickly became E4V5M6 with power of 4/5 in the right half of body which was same as compared to the preoperative period.

Results

The biopsy of the mass, however, revealed features suggestive of extra-axial supratentorial ependymoma (WHO Grade III). Immunohistochemistry supported the diagnosis of supratentorial ependymoma, NOS. The patient was then referred for further chemoradiation.

Discussion and Conclusion

We report the first case of extra-axial supratentorial ependymoma mimicking a parasagittal meningioma occurring with adjacent subdural hematoma. Clinical and imaging background along with a complete pathological examination with immunohistochemical study is essential to confirm the diagnosis of rare brain tumours.

Supratentorial extra-axial RELA fusion-positive ependymoma misdiagnosed as meningioma by intraoperative histological and cytological examinations: a case report

Background

Dura-attached supratentorial extra-axial ependymoma is a very rare type of tumor, with only nine reported cases. Preoperative diagnosis of dura-attached supratentorial extra-axial ependymoma is difficult and often radiologically misdiagnosed as a meningioma. We report a case of dura-attached supratentorial extra-axial ependymoma that was misdiagnosed using intraoperative histological and cytological examinations.

Case presentation

A 26-year-old Japanese man with headache and nausea was referred to our medical facility. Magnetic resonance imaging revealed a cystic mass of 70 × 53 × 57 mm in the left temporoparietal lobe. A peritumoral band with hyperintensity on T2-weighted imaging was observed at the periphery of the lesion, suggesting an extra-axial lesion with no apparent connection to the ventricle. A dural tail sign was also noted on the gadolinium-enhanced T1-weighted image. Preoperative clinical diagnosis was meningioma. Proliferated tumor cells in sheets with intermingled branching vessels were observed in the frozen tissue. Perivascular rosettes were inconspicuous, and the tumor cells had rhabdoid cytoplasm. The tumor was intraoperatively diagnosed as a meningioma, suspected to be a rhabdoid meningioma. Perivascular rosettes were evident in the formalin-fixed paraffin-embedded tissues, suggesting ependymoma. The tumor cells had eosinophilic cytoplasm without a rhabdoid appearance. Anaplastic features, such as high tumor cellularity, increased mitotic activity, microvascular proliferation, and necrosis, were observed. Ependymal differentiation was confirmed on the basis of ultrastructural analysis. Molecular analysis detected C11orf95-RELA fusion gene. The final diagnosis was RELA fusion-positive ependymoma, World Health Organization grade III.

Conclusion

Owing to its unusual location, dura-attached supratentorial extra-axial ependymomas are frequently misdiagnosed as meningiomas. Neuropathologists should take great precaution in intraoperatively diagnosing this rare subtype of ependymoma to avoid misdiagnosis of the lesion as other common dura-attached tumors.

Intraventricular neuroepithelial tumors: surgical outcome, technical considerations and review of literature

Background

Intraventricular neuroepithelial tumors (IVT) are rare lesions and comprise different pathological entities such as ependymomas, subependymomas and central neurocytomas. The treatment of choice is neurosurgical resection, which can be challenging due to their intraventricular location. Different surgical approaches to the ventricles are described. Here we report a large series of IVTs, its postoperative outcome at a single tertiary center and discuss suitable surgical approaches.

Methods

We performed a retrospective chart review at a single tertiary neurosurgical center between 03/2009–05/2019. We included patients that underwent resection of an IVT emphasizing on surgical approach, extent of resection, clinical outcome and postoperative complications.

Results

Forty five IVTs were resected from 03/2009 to 05/2019, 13 ependymomas, 21 subependymomas, 10 central neurocytomas and one glioependymal cyst. Median age was 52,5 years with 55.6% (25) male and 44.4% (20) female patients. Gross total resection was achieved in 93.3% (42/45). 84.6% (11/13) of ependymomas, 100% (12/21) of subependymomas, 90% (9/10) of central neurocytomas and one glioependymal cyst were completely removed. Postoperative rate of new neurological deficits was 26.6% (12/45). Postoperative new permanent cranial nerve deficits occurred in one case with 4th ventricle subependymoma and one in 4th ventricle ependymoma. Postoperative KPSS was 90% (IR 80–100). 31.1% of the patients improved in KPSS, 48.9% remained unchanged and 20% declined. Postoperative adverse events rate was 20.0%. Surgery-related mortality was 2.2%. The rate of shunt/cisternostomy-dependent hydrocephalus was 13.3% (6/45). 15.4% of resected ependymomas underwent adjuvant radiotherapy. Mean follow-up was 26,9 (±30.1) months.

Conclusion

Our surgical findings emphasize satisfactory complete resection throughout all entities. Surgical treatment can remain feasible, if institutional experience is given. Satisfying long-term survival and cure is possible by complete removal. Gross total resection should always be performed under function-remaining aspects due to mostly benign or slow growing nature of IVTs. Further data is needed to evaluate standard of care and alternative therapy options in rare cases of tumor recurrence or in case of patient collective not suitable for operative resection.

Adult cerebellopontine angle ependymoma presenting as an isolated cisternal mass: A case report

INTRODUCTION

Ependymomas represent approximately 2%-8% of all primary intracranial brain tumors. The occurrence of extra-axial posterior fossa ependymomas in adults is rare.

CASE AND OUTCOMES

We report a case of extra-axial cerebellopontine (CP) angle ependymoma in an adult patient, managed through gross total resection (GTR) and adjuvant radiotherapy. At her one-year postoperative visit, the patient remained clinically stable without any symptoms or focal neurological deficit and a follow up MRI showed no evidence of tumor recurrence.

DISCUSSION

Only six cases of adult cerebellopontine angle ependymomas have been reported in the English literature, with the left side affected more commonly. Including this case, the mean age of the reported cases of adult extra-axial CP angle ependymoma is 44.14 years (range 22-66 years). Men accounted for five out of seven cases (71.4%). Maximal surgical resection is the mainstay of treatment in extra-axial CP angle ependymomas. Among seven reported cases, five received GTR and two had subtotal resection (STR). Patients were followed an average of 13.6 months (range 2-30 months) and only two patients with STR died during the follow-up period (6 weeks and 2 months after surgery). Six of the seven reported cases (including this one) received adjuvant radiotherapy.

CONCLUSION

Although rare, extra-axial CP angle ependymomas should be considered as a differential diagnosis to other lesions of the CPA. Radical resection, whenever possible, is usually associated with a good outcome. Adjuvant radiotherapy remains an optional treatment with an unknown impact on overall and progression-free survival.

A Missed Differential in an Extra-Axial Lesion with Calvarial Involvement

Extra-axial central nervous system lesions can occasionally involve the overlying calvarium. The involvement may be due to longstanding pressure effects or secondary to the aggressive behaviour of the lesion. The spectrum of such dural-based lesions varies from infectious/inflammatory to neoplastic etiology. We present a dural-based lesion with the erosion of the overlying calvarium in a young lady. In view of the short history with heterogenous enhancement on magnetic resonance imaging and bony erosion, hemangiopericytoma or malignant meningioma was suspected. The histopathology, however, proved it to be an anaplastic (grade III) ependymoma. Extra-axial ependymomas though uncommon have been reported. However, these extra-axial ependymomas presenting with calvarial erosion are unknown. The bony erosion, as in the present case, may suggest an aggressive tumour behaviour. The reported extra-axial supratentorial ependymomas along with their salient radiological/operative features are shortly reviewed. Also, the differentials of extra-axial lesions with calvarial involvement are touched upon.