Granular cell astrocytoma.

Granular cell astrocytoma (GCA) is a rare morphologic variant of astrocytomas, characterized by a prominent component of plump granular tumor cells. It has an aggressive clinical course as compared with conventional astrocytoma of the same grade. As its cytologic feature resembles that of a foamy histiocyte and, histologically, the tumor is rich in arborizing capillaries, it can be difficult to distinguish GCA from non-neoplastic diseases such as infarct or demyelinating disease. In this paper, a case of a GCA in a 28-year-old full-term pregnant woman suffering from a sudden episode of seizure during delivery is described, focusing on histopathological, immunohistochemical, and ultrastructural features. Histopathology and immunohistochemical phenotype of this tumor were identical to the previous reports. Ultrastructurally, secondary lysosome (so-called lipofuscin bodies) granules were present but not numerous; instead, many mitochondria and unusual paracrystalline inclusions were found in each tumor cell. In our case, the light microscopic granular appearance might be produced not only by phagolysomes but also by numerous mitochondria and paracrystalline inclusions.