Report of a case of giant cell ependymoma with unusual clinical and pathological presentation

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.

When a dermatopathologist encounters the ultra-rare: A case series of superficial soft tissue/cutaneous myxopapillary ependymomas

Myxopapillary ependymoma (MPE) is an uncommon variant of ependymoma, almost exclusively seen in conus medullaris or filum terminale. MPE can be diagnostically challenging, especially when arising extra-axially. Here we report 5 cases of superficial soft tissue/cutaneous MPE, identified across three tertiary institutions. All patients were female and three of them (3/5, 60%) were children (median age 11 years, range 6-58 years). The tumors presented as slow-growing masses of the sacrococcygeal subcutaneous soft tissues, occasionally identified after minor trauma and clinically favored to be pilonidal sinuses. Imaging showed no neuraxis connection. Macroscopically, tumors were well-circumscribed, lobulated, and solid and microscopically they exhibited typical histopathology of MPE, at least focally. Two of the tumors (2/5, 40%) showed predominantly solid or trabecular architecture with greater cellular pleomorphism, scattered giant cells, and increased mitotic activity. All tumors (5/5, 100%) showed strong diffuse immunohistochemical expression of GFAP. One tumor clustered at the category "ependymoma, myxopapillary" by methylome analysis. Two patients (2/5, 40%) had local recurrence at 8 and 30 months after the initial surgery. No patients developed metastases during the follow-up period (median 60 months, range 6-116 months). Since a subset of extra-axial MPEs behaves more aggressively, timely and accurate diagnosis is of paramount importance.

Pediatric Extraspinal Subcutaneous Sacrococcygeal Myxopapillary Ependymoma: Case Report and Minireview

ABSTRACT

A 9-year-old girl presented with a slow-growing and painless mass for 7 months in the soft tissue of the sacrococcygeal region. Magnetic resonance imaging revealed a well-circumscribed solid mass located in the subcutaneous soft tissue of the sacrococcygeal area, but not affecting bone structures. The mass was completely removed, and the disorder was diagnosed as myxopapillary ependymoma. In addition, the MYCN gene amplification status of the tumor was evaluated. Extra-axial ependymomas are very rare tumors with a tendency to metastasis, but they are usually regarded as low-grade ependymomas. Long-time surveillance and follow-up are necessary even after complete excision. Besides, we also discuss the diagnosis of primary soft tissue myxopapillary ependymoma.

Extra-axial sacral soft tissue giant cell ependymoma affecting a child: Case report and review of the literature

An otherwise healthy eight-year-old girl presented with a mass in the soft tissue of the sacral region. The lesion was diagnosed as a vascular malformation on imaging studies, for which percutaneous sclerotherapy was attempted. The mass continued to grow and a complete resection was performed after four years. The pathological diagnosis was giant cell ependymoma (GCE). GCE is a term used to describe a rare histologic variant of ependymoma characterized by malignancy-like morphologic phenotype and indolent behavior. To the best of our knowledge, this is the first case of extra-axial soft tissue sacral GCE reported in a child.