Subependymal giant cell astrocytoma with oncocytic change.

A 49-year-old woman presented with a history of periodic episodes of nausea and vomiting starting in 2006. In June 2009, the patient lost consciousness and was transported to our hospital. Head computed tomography (CT) revealed hydrocephalus caused by an enhancing mass lesion with calcification located in the right lateral ventricle around the foramen of Monro. Total tumor removal was performed. Histologic findings revealed fibrillated spindle tumor cells and giant tumor cells with abundant cytoplasm. The spindle tumor cells were immunoreactive for GFAP and S-100 protein, but none of the giant tumor cells were immunoreactive for GFAP or S-100 protein. Electron microscopic examination revealed abundant mitochondria in the tumor cell cytoplasm. According to these findings, this tumor was diagnosed as subependymal giant cell astrocytoma (SEGA) with oncocytic change, which is extremely rare.