Lipidized giant-cell glioblastoma of cerebellum.

Glioblastoma multiforme is recognized rarely in the cerebellum. We describe a peculiar case with lipid accumulation in giant tumor cells, possibly the second example so far reported in this unusual location. A 46-year-old man with a 5-month history of headache, vomiting, dizziness and instability of gait, was found to have on magnetic resonance imaging an expanding mass situated deep in the left cerebellar hemisphere. The lesion was hypointense in T 1- and hyperintense in T2-weighted images, had poorly defined borders, peripheral edema and annular foci of contrast enhancement. Eight months after subtotal removal and radiotherapy, control MRI showed tumor recurrence with aggressive features. The patient was alive 15 months after operation but follow-up was eventually lost. Histologically, the tumor showed marked pleomorphism, with many giant cells characterized by finely vacuolated cytoplasm strongly suggestive of lipid accumulation. There were few, sometimes atypical mitotic figures and foci of endothelial proliferation. The tumor cells were strongly positive for GFAP, vimentin and S100 protein, all of which stressed the foamy appearance of the giant cells. About 15% of nuclei were positive for Ki-67. We considered the case to be a so-called lipidized glioblastoma, first recognized as a subtype by Kepes and Rubinstein [1981]. Differential diagnosis with anaplastic pleomorphic xanthoastrocytoma is discussed.