A man of 32 years was admitted with a 3-month history of temporal lobe epilepsy. CT-Scan showed a well-circumscribed area of heterogenous contrast enhancement in the right temporal lobe. Gross total resection was performed but the tumor recurred: the patient died 6 months after the onset of symptoms. There was no autopsy. Histology revealed a highly pleomorphic neoplasm with extensive zones of necrosis. Monster cells, up to several hundred micrometers in diameter, with multiple and/or multi-lobed nuclei were numerous and showed emperipolesis for polymorphonuclear, mononuclear, and small tumor cells. Abundant mitoses were observed. Tumor cells of all sizes had ground-glass or vacuolated cytoplasm which obscured their glial nature. GFAP was demonstrated in some neoplastic cells. Reticulin fibers were confined to perivascular areas where mononuclear inflammatory cells were sometimes noted. Vascular proliferation was mild. Electromicroscopic study revealed that the cytoplasms of the tumor cells contained abundant lipid droplets, numerous mitochondria, and glio-filaments. Such a tumor has been reported recently as "malignant glioma with heavily lipidized tumor cells". This rare entity, previously reported as xanthosarcoma of the brain, represents a subgroup of primitive monstrocellular cerebral tumors.