Intraventricular tanycytic ependymoma: case report and review of the literature

Whorling Sclerosing Ependymoma of the Cervical Spinal Cord Presenting Tanycytic Histopathologic Features: A Rare Case Report

Tanycytic ependymoma is a neuroectodermal tumor that arises from ependymoglial cells or tanycytes. It is highly uncommon. We reported a 34-year-old man who was diagnosed with intradural-intramedullary tanycytic ependymoma, located at the level of C4-5 who had a 9-months history of neck pain and left arm pain, and numbness on fingers. One month prior to presentation, his left arm numbness and paresthesia deteriorated. The lesion was removed totally by C4, C5 hemilaminoplasty. The histologic pattern of this lesion was consisted of fascicles forming nebula-like whorling structures. Because of these structures, tanycytic ependymoma should be taken into consideration in the differential diagnosis of a whorling-sclerosing variant of meningiomas.

Conventional and Advanced Magnetic Resonance Imaging Features of Supratentorial Extraventricular Ependymomas

OBJECTIVE

To describe the magnetic resonance imaging characteristics of supratentorial ependymomas.

METHODS

The magnetic resonance imaging and computed tomography imaging characteristics of 49 cases of supratentorial ependymomas were analyzed retrospectively. The location, size, degree of perilesional edema, gross appearance, computed tomography attenuation characteristics, T1 and T2 signal intensity characteristics, degree of diffusion restriction, presence of calcification, and hemorrhage were documented for each lesion. The intratumoral susceptibility scores (ITSS), apparent diffusion coefficient (ADC) values, relative cerebral blood volume, and choline/N-acetyl aspartate ratios were documented where available.

RESULTS

The frontal lobe was the most common location with a mean size of 6.37 × 4.8 cm. Severe perilesional edema was evident in 30%. Heterogenous, solid-cystic appearance was present in 96% lesions, with 95% of extraventricular lesions extending from pial surface to the ventricular margin. Calcification was seen in 55% of cases. The ITSS was 3 in 85.7% of lesions. The mean ADC value calculated was 600 × 10 mm/s. The mean relative cerebral blood volume on dynamic susceptibility contrast perfusion was 4.83. The mean choline/N-acetyl aspartate ratio was 5.87. Leptomeningeal dissemination was demonstrable in 5 lesions. Four lesions were abutting the dura with frank dural invasion in one. One patient presented with disseminated disease without evidence of a primary lesion.

CONCLUSIONS

A large lesion with relatively well-defined margins, heterogeneous solid cystic appearance, extending from the pial surface to the ventricular margin, presence of calcification, and ADC values approaching those of white matter should raise a suspicion of supratentorial ependymoma. High ITSS, MR perfusion parameters, and magnetic resonance spectroscopy characteristics are similar to those of other high-grade gliomas.

Tanycytic ependymoma of filum terminale: Clinical characteristics and surgical outcomes

Tanycytic ependymoma (TE), a rare subtype of ependymoma, was classified as grade II ependymoma by the World Health Organization in 2000 and 2007. Preoperative diagnosis of TE is challenging due to its similarities to schwannoma and astrocytoma; therefore, differentiation is required. The present study investigated the clinical, imaging and pathological characteristics of TE in the filum terminale. A retrospective analysis was conducted on the clinical, imaging, pathological and immunohistochemical characteristics of 8 patients with TE in the filum terminale and the relevant literature was reviewed. Of the 8 patients 7 were female and 1 was male, with an age range of 24–62 years old. The primary clinical symptom observed was lumbago, accompanied by lower limb pain and numbness. Magnetic resonance imaging predominantly identified isointensity on thoracic (T) 1-weighted images and iso- or hyperintense signal intensity on T2-weighted images, with homogeneous or inhomogeneous enhancement. All patients underwent resection of the tumor through a posterior median approach, and total resection was acighieved in 7 patients. During postoperative follow-up, all patients experienced improvement compared with their preoperative status, and were without tumor recurrence. The present study comprised the largest group of cases with TE in the filum terminale reported so far, to the best of our knowledge, which could foster a better understanding of this disease. Complete surgical resection of the tumor has the greatest effectiveness of any treatment for TE in the filum terminale. Postoperative histological examination, immunohistochemistry and electron microscopy for tumor specimens may assist in its diagnosis and differential diagnosis.

Cerebellar ependymoma with overlapping features of clear-cell and tanycytic variants mimicking hemangioblastoma: a case report and literature review

BACKGROUND

Imaging and histology of clear-cell ependymoma and cerebellum-based hemangioblastoma are similar; distinguishing between them is a diagnostic challenge.

CASE PRESENTATION

A 62-year-old Chinese woman presented with an intermittent headache of 8 years' duration. Computed tomography and magnetic resonance imaging revealed a mass in the cerebellum. Neurological imaging suggested hemangioblastoma (HB). Histologically, the tumor included cellular and paucicellular areas, in which cells were arranged in nests or diffusely distributed; and a highly vascular area, in which tumor cells were arranged in clusters and separated by capillaries. At low magnification, the tumor mimicked cellular HB, but at high magnification, tumor cells showed clear cytoplasm instead of the vacuolated cytoplasm typically observed in HB. Moreover, spindly, bipolar elements resembling tanycytes were observed within the nest structures. Although these features indicated the possibility of ependymoma, neither true ependymal rosettes nor an ependymal-lined profile was observed. The tumor was characterized by prominent vascularity, but glomeruloid formation was absent. We saw pleomorphism in foci of some tumor giant cells, but pathologic mitosis and palisaded necrosis were absent. Most tumor cells were positive for glial fibrillary acidic protein and S100. Epithelial membrane antigen was expressed with a paranuclear dot-like or a ring-like pattern. The Ki-67 index was approximately 2%. Considering the patient's symptom, neurological imaging, and pathological findings, she was diagnosed as cerebellar ependymoma (WHO grade II).

CONCLUSIONS

Here, we report a case of ependymoma with overlapping clear-cell and tanycytic features, and review the literature to evaluate its real incidence. Pathologists should consider this rare diagnosis when confronted with a similar presentation.

Anaplastic supratentorial cortical ependymoma presenting as a butterfly lesion

BACKGROUND

Anaplastic cortical ependymomas are rare lesions with few cases reported in the literature.

CASE DESCRIPTION

We present a unique case of an anaplastic cortical ependymoma in a 51-year-old female presenting as a butterfly lesion with involvement of both frontal lobes. The patient underwent gross total resection of her tumor with further adjuvant treatment. We present the findings in our case and review the literature surrounding supratentorial ependymomas and their treatment outcomes.

CONCLUSION

Rarely, cortical ependymoma can present as a butterfly lesion and should be considered in the differential diagnosis of such lesions in adults.

Masses and malformations of the third ventricle: normal anatomic relationships and differential diagnoses

The third ventricle lies in the center of the brain. It is surrounded by critical nuclear structures (the hypothalamus and thalami) and important glandular structures (the pituitary and pineal glands). Although a wide array of pathologic processes may involve the third ventricle, most are extrinsic masses. By understanding the anatomic boundaries of the third ventricle and its relationship to adjacent structures, it is possible to create short lists of differential diagnoses. Third ventricle masses can be classified as arising in or immediately adjacent to one of five locations: anterior, posterior, inferior, foramen of Monro, and intraventricular. Anterior masses involve the optic and infundibular recesses, posterior masses affect or arise in the posterior commissure and pineal gland, and inferior masses involve or affect the ventricle floor. Masses may also arise at or adjacent to the foramen of Monro or entirely within the third ventricle. Of the intraventricular masses, chordoid glioma-a rare low-grade primary neoplasm-is unique to the third ventricle. Congenital malformations of the third ventricle are uncommon and are most often noted during childhood. Most commonly, these anomalies represent malformations of the neurohypophysis, which may manifest as hormonal abnormalities, or stenosis of the aqueduct of Sylvius, which manifests as dilatation of the third and lateral ventricles (hydrocephalus).

Spinal tanycytic ependymoma with diffusion restriction on MRI

Tanycytic ependymoma is a rare spindle-cell variant of ependymoma derived from tanycytes. Primitive neuroectodermal tumors usually have diffusion restriction, whereas ependymomas do not. Here, we present a case of tanycytic ependymoma with diffusion restriction. As far we are aware, this is the first case of tanycytic ependymoma in the English literature with diffusion restriction.

Imaging of ependymomas: MRI and CT

The imaging features of intracranial and spinal ependymoma are reviewed with an emphasis on conventional magnetic resonance imaging (MRI), perfusion MRI and proton magnetic resonance spectroscopy, and computed tomography. Imaging manifestations of leptomeningeal dissemination of disease are described. Finally, salient imaging features obtained in the postoperative period to evaluate completeness of surgical resection, and thereafter for long-term surveillance for disease recurrence, are reviewed.

Chordoid glioma of the third ventricle: a report of two cases, one with ultrastructural findings

Chordoid glioma, which generally occurs in adults, is a rare CNS tumor arising in the anterior part of the third ventricle. We report two cases of chordoid glioma of the third ventricle in a 42-year-old woman and a 51-year-old man, respectively. Both tumors showed essentially the same histological and immunohistochemical features; the tumors were composed of cords and nests of epithelioid, GFAP-immunoreactive cells in a mucinous stroma with lymphoplasmacytic infiltrates at the tumor periphery. Ultrastructural examination in one case revealed that the tumor cells were characterized by the presence of hemidesmosomes and associated focal basal lamina formation, intermediate junctions, microvilli and cilia, and intercellular microrosettes with microvilli. Of interest was that small blood vessels with fenestrated endothelial cells were present in the stroma. In the brain, the presence of fenestrated endothelial cells is a feature of the circumventricular organs (except the subcommissural organ), among which the organum vasculosum of the lamina terminalis is located in the anterior part of the third ventricular floor that is lined by specialized ependymal cells known as tanycytes. These findings further strengthen the hypothesis that chordoid glioma may represent a peculiar clinicopathological subtype of ependymoma (chordoid ependymoma) originating from the lamina terminalis area.

Pediatric tanycytic ependymoma of the cauda equina: case report and review of the literature

Tanycytic tumors of the cauda equina region are being increasingly reported. Such tumors can occur among pediatric patients and adults. An unusual case of tanycytic ependymoma located at the region of the cauda equina is reported in a girl. The clinical presentation, radiological features, intraoperative findings, and histopathologic features are described. The prognostic significance of differentiating such a neoplasm from other intramedullary tumors is noted. A heightened awareness of this pathologic entity among neurosurgeons and pathologists will help in diagnosing this neoplasm and in enabling better patient management.

Tanycytic ependymoma arising from the right lateral ventricle: a case report and review of the literature

A 38-year-old man presented with a year-long history of worsening headache. Neuroradiological findings showed that a solid cystic mass occupied the right lateral ventricle. Histologically, the tumor composed of nuclear dense zones consisting of a cluster of spindle cells and fibrillary zones consisting of streaming of cell processes. The tumor cells showed the characteristics of monopolar or bipolar processes. Some tumor cell processes extended to the vessel wall and formed ill-defined perivascular rosettes. No mitoses or necrosis were found. The cells presented positive for GFAP, S-100 protein, vimentin, Nestin and neurofilament, and dotlike positive for epithelial membrane antigen, but negative for Syn and NeuN. Four cases of tanycytic ependymoma arising from the lateral ventricle have been reported in literature. Histological differential diagnosis includes spindle-shaped neuroepithelial tumors, such as pilocytic astrocytoma, fibrillary astrocytoma and schwannoma. Tanycytic ependymoma has slightly better prognosis than other ependymoma subtypes.