Subependymal giant cell astrocytoma: clinical, histologic and immunohistochemical characteristic of 3 cases.

Three cases of subependymal giant cell astrocytoma (SEGA) in the women aged 23, 26, and 36 years were reported. Two of them had no clinical evidence of tuberous sclerosis complex (TSC) and the one woman presented apparent mental retardation. All patients manifested sudden clinical onset with symptoms of elevated intracranial pressure due to tumor of lateral ventricles and obstructive hydrocephalus. At surgery, the neoplasm was removed totally in one case and resected partially in 2 cases. Histologically, the tumors were composed of large polygonal cells with vesicular nuclei, prominent nucleoli and glassy eosinophilic cytoplasm, intermingled with spindle and small cells. In addition, multinucleated and bizarre giant cells were present, but they were very numerous in one case only. The tumor cells revealed in all cases variegated immunoreactivity for glial fibrillary acidic protein (GFAP), S-100 protein, vimentin (VIM) and neuron-specific enolase (NSE), with stronger expression of VIM than GFAP in 2 cases. Immunostaining of neurofilament proteins and synaptophysin was negative. The results suggest rather astroglial incomplete or aberrant differentiation and maturation than neuronal differentiation of tumor cells. The immunohistochemical variations of SEGA in asymptomatic TSC cases and those associated with tuberous sclerosis are discussed.