Prolymphocyte transformation of chronic lymphocytic leukaemia manifesting as a cerebellar lymphoma

A 75-year-old woman presented with symptoms related to a space occupying lesion in the cerebellum which histology showed to be a malignant lymphoma of prolymphocytic type. A diagnosis of chronic lymphocytic leukaemia (CLL) had been made over 1 year before. This form of lymphoma complicating CLL has not been described previously in the nervous system.