T-cell primary leptomeningeal lymphoma in cerebellopontine angle.

Primary meningeal lymphomas are very rare and those derived from T cells are even more infrequent (less than 5% of primary central nervous system lymphomas). Cerebellopontine angle involvement in the primary T-cell lymphoma is exceptional. Clinical presentation depends on the type of lesions, and histological diagnosis is needed. We present a rare case of a 50-year-old woman who presented with clinical cerebellar syndrome with posterior opsoclonus-myoclonus syndrome. Necropsy evaluation revealed primary diffuse leptomeningeal non-Hodgkin's T-cell lymphoma.