[Histological study of malignant cerebral granular cell tumor].

Granular cell tumor (GCT), which is suspected to be of Schwann cell origin, sometimes grows in the subcutaneous tissue, oral cavity and visceral sites and this tumor has a rather benign nature. Intracranial GCT also grows in the neurohypophysis but rarely in the brain parenchyma. We reported a case of intra-cerebral GCT in the left hemisphere, which took a malignant course. The patient was a 62-year-old male with a history of slowly progressing right hemiparesis and aphasia since May 1986. He was in a drowsy state and showed right hemiplegia on admission (October 14, 1986). Radiological examinations revealed a tumor and surrounding edema in the left temporal lobe and basal ganglia . Resection of the tumor and both radiotherapy of 53 Grey and chemotherapy using ACNU (total 310 mg) and BrdU (500 mg, two times per week prior to radiation) were applied after the operation. Although the tumor disappeared once after these treatments, the patient died of recurrence on July 3, 1987. Histological examinations on the specimen taken at the first operation revealed that the tumor consisted of rather round, large and small cells with a few cell processes. The large cells often had bizarre and multiple nuclei. These large cells had rich eosinophilic granular particles of various size and vacuoles in their cytoplasm. The staining for antiglial fibrillary acidic protein (GFAP) was positive in a part of the cytoplasm and cell processes. Electron microscopically various sized and shaped granular structures and intermediate filaments were noticed in the cytoplasm of both large and smaller cells.(ABSTRACT TRUNCATED AT 250 WORDS)