Extra-axial Ependymomas Research Articles

Supratentorial extra-axial anaplastic ependymoma: a rare case report.

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. 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. 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. 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.

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

BackgroundDura-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 presentationA 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.ConclusionOwing 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.

Ovarian ependymoma presenting in pregnancy: a case report and literature review

BackgroundOvarian ependymoma is a rare malignancy. Because of the extreme rarity, certain features of the neoplasm, including its clinical behaviour and optimal therapy, are incompletely characterized.Case presentationA 32-year-old pregnant woman at term presented with a left ovarian neoplasm that occurred in the early stage of pregnancy. She underwent left adnexectomy during the caesarean section, and the neoplasm was histologically and immunohistochemically identified to be ovarian ependymoma. Immunohistochemical staining with oestrogen receptors and progesterone receptors showed strong positive staining. According to reports in the literature, the pathological type of ovarian ependymoma in our patient was the extra-axial type. Interestingly, the foetus was also found to have bilateral ependymal cysts during pregnancy. The patient received no further surgical treatment or adjuvant therapy. She and her 14-month-old baby both have no evidence of disease at present. The follow-up of both mother and child is still continuing.ConclusionsThe case presented here illustrates high levels of oestrogen during pregnancy may stimulate viable malignant ependymal cells to proliferate. Hence, young women with extra-axial-type ependymomas may not be suitable for fertility preservation. Moreover, hormone-based therapies can be a potentially effective treatment for women with extra-axial ependymomas.

Primary peritoneal ependymoma

Extra-axial ependymomas are exceedingly rare neuroectodermal tumors that arise outside the central nervous system. The majority behave in a benign clinical fashion. In this case, an elderly woman developed an intraperitoneal ependymoma that after surgical excision recurred twice over a period of twenty four years. At each presentation, the tumor demonstrated identical histologic appearances with prominent rosettes as well as perivascular pseudorosettes. Immunohistochemistry showed strong positivity for glial fibrilary acidic protein, estrogen receptors, CAM 5.2 and CD99 with weak staining for pankeratin. Staining was negative for epithelial membrane antigen (EMA) and S-100. Ultrastructurally, the neoplasm showed neuroectodermal features, including filamentous cytoplasm and abundant intercellular bridges. The patient had no lesions in the central nervous system or the para-spinal region, suggesting that this tumor arose spontaneously within the abdominal cavity.

Intracranial Extra-Axial Ependymoma in the Ambient Cistern That Initially Presented as Calcification: A Report of Case

Ependymomas usually occur in intraventricular or intraspinal locations. Intracranial extraaxial ependymomas (IEAEs) are very rare. Here, we present an unusual case of an IEAE in 25-year-old man. The patient experienced head trauma two and half years prior to presentation, at which time brain computed tomography (CT) showed only a dense calcification in the left ambient cistern. After two and a half years, follow up brain CT and magnetic resonance imaging depicted interval growth of a calcified mass with cystic change. The tumor was successfully treated surgically, and the pathologic examination confirmed ependymoma. Index terms Extra-Axial Intracranial Ependymoma

Intracranial extraaxial ependymoma in children: a rare case report and review of the literature

Intracranial extraaxial ependymomas (IEAEs) are extremely rare. We present a pediatric patient with IEAE misdiagnosed as a meningioma preoperatively, successfully treated surgically with a favorite outcome. The literature about IEAEs was briefly reviewed. Thereafter we discuss the clinical characteristics of the disease.

Ependymomas of the Central Nervous System and Adult Extra-axial Ependymomas are Morphologically and Immunohistochemically Distinct—A Comparative Study With Assessment of Ovarian Carcinomas for Expression of Glial Fibrillary Acidic Protein

Extra-axial ependymomas are very rare but have been reported in the ovary, broad ligament, sacrococcygeal region, lung, and mediastinum. The histogenesis is obscure, and a thorough immunohistochemical analysis is lacking. We reviewed the morphologic and immunohistochemical features of 5 extra-axial ependymomas occurring in adults, 1 arising in an infantile sacrococcygeal teratoma, and a control group of 10 central nervous system (CNS) ependymomas in adults. All cases were evaluated for expression of epithelial membrane antigen, estrogen receptor (ER), progesterone receptor (PR), WT1, CD99, CK18, AE1:3, CAM 5.2, 34betaE12, CK7, CK20, synaptophysin, chromogranin, and glial fibrillary acidic protein (GFAP) using formalin-fixed, paraffin-embedded tissue. One hundred twelve ovarian carcinomas in 3 tissue microarrays were also studied with GFAP. The adult extra-axial cases demonstrated more architectural variability than the CNS cases. We observed that both the CNS and adult extra-axial ependymomas expressed GFAP diffusely, whereas only 9 stage III, high-grade ovarian serous papillary carcinomas stained with GFAP (2 strongly and diffusely and 7 exhibiting focally weak expression). There were significant immunophenotypic differences between adult extra-axial and CNS ependymomas, with extra-axial cases preferentially expressing 34betaE12 (60% vs. 0%), CK18 (100% vs. 20%), CAM 5.2 (60% vs. 10%), CK7 (80% vs. 10%), ER (100% vs. 10%), and PR (80% vs. 20%). Two spinal cord ependymomas expressed CK18, 1 expressed CK7, and 1 expressed CAM 5.2. CNS ependymomas more frequently expressed CD99 (100% vs. 20%). The following stains were not differentially expressed: epithelial membrane antigen (expressed in 2 of 15 cases, including both extra-axial and CNS ependymomas), synaptophysin (1/15), chromogranin (0/15), WT1 (8/15), AE1:3 (10/15), and CK20 (0/15). The ependymal elements of the sacrococcygeal tumor failed to express 34betaE12, CK18, CAM 5.2, and CK7, like most CNS ependymomas. The morphologic and immunophenotypic differences between extra-axial and CNS ependymomas suggest that they derive from distinct precursors and/or differentiate along distinct pathways. The differential diagnosis of extra-axial ependymomas is extensive, and GFAP expression in primary ovarian serous carcinomas, although rare, could theoretically contribute to diagnostic difficulties. ER and PR expression in extra-axial ependymomas may provide targets for hormonal therapy.

Extraaxial ependymoma of the posterior fossa

A case of extraaxial ependymoma of the posterior fossa, arising along the inferolateral aspect of the left cerebellar hemisphere, is reported. The clinical, radiologic, and histologic features of this lesion are presented. The unusual location of the tumor and its possible origin are discussed in the light of previous experience with other extraaxial ependymomas of the neuraxis.