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A 39 YEAR‐OLD MAN WITH A CEREBELLAR MASS AND PANCYTOPENIA

A 39 year-old man presented with gait difficulties, headaches, bilateral tremor, and pancytopenia. An MRI revealed a T2 hyperintense 1.7 cm mass within the right cerebellum with associated leptomeningeal enhancement and additional lesions in the cervical and thoracic spine. A biopsy showed a moderately to highly cellular neoplasm composed of tumor cells with mild nuclear pleomorphism, round to oval nuclei, delicate chromatin and occasional clear perinuclear halos in a rich basophilic mucinous background. Rare mitotic figures were seen, but there was no microvascular proliferation or necrosis. A bone marrow biopsy also revealed aggregates of malignant cells resembling those encountered previously in the cerebellum. By immunohistochemistry the tumor was positive for S-100 protein, GFAP and WT1. FISH also detected deletions of both 1p and 19q chromosomes. These findings confirmed a cerebellar oligodendroglioma with bone marrow metastasis. To date, less than 30 cases of primary infratentorial oligodendrogliomas have been published and none had genetic confirmation. To our knowledge, this represents the first wellsupported case of cerebellar oligodendroglioma in the literature. Correspondence 254 Brain Pathology 22 (2012) 251–254 © 2012 The Authors; Brain Pathology © 2012 International Society of Neuropathology