Giant cell ependymoma (GCE) is a very uncommon variant of ependymoma, known for having varying degrees of nuclear pleomorphism. There are only 34 reported cases of GCE in the English literature. We describe an additional case of a young woman who presented with a tumor located in sacral soft tissue, which was not connected to the spinal cord and did not show additional lesions in the central nervous system. Complete tumor resection was performed and no recurrences or metastasis were detected after 5 months of follow-up. Only one of all the reported GCE was located in the sacral subcutaneous region, where ependymomas are rarely found and usually have myxopapillary histology. Ours is the second report showing microscopic features of GCE in the soft-tissue region. GCE should be considered in the differential diagnosis of lumbosacral subcutaneous tumors to avoid misdiagnosing it as a malignant lesion. Since GCE could be an extraspinal extension of an intraneural ependymoma, it would be important to evaluate whether it is connected to the spinal cord.
Keywords: cytokeratin; filum terminale; giant cell ependymoma; myxopapillary; sacral.
© 2019 Japanese Society of Neuropathology.