Cytologic features of giant cell ependymoma: a case report and review of the literature

A case of myxopapillary ependymoma with predominant giant cell morphology: A rare entity with comprehensive genomic profiling and review of literature

In the evolving landscape of ependymoma classification, which integrates histological, molecular, and anatomical context, we detail a rare case divergent from the usual histopathological spectrum. We present the case of a 37-year-old man with symptomatic spinal cord compression at the L3-L4 level. Neuroradiological evaluation revealed an intradural, encapsulated mass. Histologically, the tumor displayed atypical features: bizarre pleomorphic giant cells, intranuclear inclusions, mitotic activity, and a profusion of eosinophilic cytoplasm with hyalinized vessels, deviating from the characteristic perivascular pseudorosettes or myxopapillary patterns. Immunohistochemical staining bolstered this divergence, marking the tumor cells positive for glial fibrillary acidic protein and epithelial membrane antigen with a characteristic ring-like pattern, and CD99 but negative for Olig-2. These markers, alongside methylation profiling, facilitated its classification as a myxopapillary ependymoma (MPE), despite the atypical histologic features. This profile underscores the necessity of a multifaceted diagnostic process, especially when histological presentation is uncommon, confirming the critical role of immunohistochemistry and molecular diagnostics in classifying morphologically ambiguous ependymomas and exemplifying the histological diversity within MPEs.

Cerebrospinal fluid and intraoperative squash cytology of childhood ependymoma

Ependymomas are glial neoplasms of central nervous system originated from the ependymal lining of the brain ventricles and spinal cord central canal, and rarely exfoliated into cerebrospinal fluid (CSF). In this case we report the cytomorphological and immunocytomorphological features of ependymoma in CSF and intraoperative squash preparations, confirmed by histology.

Giant Cell Ependymoma of Cervicomedullary Junction: A Case Report of a Long-Term Survivor and Literature Review

BACKGROUND

Ependymoma accounts for 3%-9% of all neuroepithelial tumors. Giant cell ependymoma (GCE) is a rare and distinct variant, with only 22 cases described in the literature. The 2007 World Health Organization classification first acknowledged this rare subtype. The cytologic features of GCE include the presence of pleomorphic giant cells with several cellular atypias, which at intraoperative frozen diagnosis may appear to be high-grade glial lesions. Despite its apparently malignant histology, GCE seems to be a neoplasm with a relatively good prognosis. Extended tumor removal is the gold standard without adjuvant treatment.

CASE DESCRIPTION

We describe the first case, to our knowledge, of GCE situated at the cervicomedullary junction in a 62-year-old patient. Surgery was performed with combined intraoperative monitoring of motor evoked potentials and somatosensory evoked potentials. Intraoperative frozen diagnosis revealed a high-grade glial neoplasm; however, gross total resection was achieved. The definitive diagnosis was GCE. At follow-up evaluation 11 years after surgery, the patient did not present with any tumor recurrence.

CONCLUSIONS

As the intraoperative diagnosis can be misleading, whenever a cleavage plane is recognized, it is essential to perform a gross total resection with the aid of intraoperative neurophysiologic monitoring, to improve prognosis and neurologic outcome. Data reported in the literature show that prognosis is mainly influenced by grade of resection.

Intraoperative squash cytology and histology of giant cell ependymoma: A diagnostic dilemma

Giant cell ependymomas (GCE) are extremely rare tumors, with 24 cases described in the literature. Squash cytology is a rapid, reliable, simple technique for intraoperative consultation in neurosurgical practice. We describe a rare case of GCE arising at level of L4-L5 in a 66-year-old woman and discuss the cytologic/histologic features. Intraoperative smears were highly cellular with a prominent fibrillary background and exhibited papillary structures and sheets composed of highly atypical and bizarre cells. Some of the cells showed nuclear pseudoinclusions and rarely formed pseudorosette-like arrays. Intraoperative diagnosis was high grade glial tumor. On paraffin sections, besides extensive polymorphism, there were no microvascular proliferation, necrosis, and mitosis and the final diagnosis was WHO grade II GCE. GCE may be a diagnostic challenge on intraoperative smears, frozen, and paraffin sections. It must be kept in mind in the differential diagnosis of giant cell exhibiting benign and malignant tumors of brain.

Immunohistochemical features of giant cell ependymoma of the filum terminale with unusual clinical and radiological presentation

BACKGROUND

Giant cell ependymoma of the filum terminale is a rare variant, generally manifested as a well-circunscribed intradural mass with an indolent biological behavior.

CASE PRESENTATION

We describe the case of a 48-year-old Mexican female who non-relevant past medical history, that developed a GCE of the filum terminale. Magnetic resonance imaging and computed tomography revealed the presence of an intra-axial tumor extending from L3 to L5 with extra-medullary invasion. Therefore the tumor was considered unresectable and only incisional biopsy was obtained, establishing the tentative diagnosis of a poorly differentiated neoplasia. A second evaluation of the case revealed the presence of numerous non-cohesive pleomorphic giant cells with intranuclear inclusions and broad eosinophilic cytoplasm, alternating with intermediate size cells with round, hyperchromatic nuclei and forming a perivascular pseudo-rosettes pattern. The ependymal phenotype was supported by light microscopy and corroborated by immunohistochemistry analysis. The patient was subsequently treated with radiotherapy 54Gy. She is alive after a 27-month follow-up, with residual disease, difficulty ambulating and pain.

CONCLUSIONS

GCE of filum terminale may have an atypical clinical and radiological presentation, albeit with invasive characteristics and anaplasia on histologic analysis. However, its biological behavior is indolent and associated to longer survival. Due to the presence of giant cells, the differential diagnosis of other primary neoplasias at that site were considered, including paraganglioma, malignant peripheral nerve sheath tumors as well as metastatic malignant melanoma, adrenal carcinoma, thyroid gland carcinoma and urothelial carcinoma, that may all harbor giant cells.