Subependymal Gian Cell Astrocytoma in An Adult Without Tuberous Sclerosis Complex: A Neuropathologial Case Report of a Tumor Initially Misdiagnosed as Glioblastoma

Abstract

Subependymal giant cell astrocytomas (SEGA) are WHO CNS grade 1 tumors, predominantly diagnosed in the pediatric and young adult populations and almost always encountered in the context of the tuberous sclerosis complex (TSC). SEGAs develop from subependymal nodular (SEN), which are a component of TSC, while both have similar radiological and histological. Char-acteristically, SEN are small lesions that are growth stable and typically do not produce symptoms, while SEGAs are steadily growing lesions that produce compression-associated symptoms due to their periventricular location. Histologically, SEGAs present with pleomorphic, epitheloid-like, and giant multinucleated cells, with other glial phenotypes such as pyloid, histiocytic, and others also present. Tumors are sharply demarcated from the surrounding parenchyma and, other than the striking cellular appearance, may also show areas of palisading necrosis, making the histopathological diagnosis challenging. In cases of older patients or when a history of TSC is either not present or not known by the neuropathologist, the differential diagnosis can be quite challenging and includes a myriad of either lower-grade neuroglial tumors as well as high-grade astrocytic ones. Herein, we present a neuropathological case report of a 63-year-old female with no known TSC history and a CNS tumor with morpho-logical characteristics of SEGA.