Abstract
Prolymphocytic leukemia (PLL) is a generalized malignancy of the lymphoid tissue characterized by the accumulation of monoclonal lymphocytes, usually of B cell type. Involvement of the central nervous system (CNS) is an extremely rare complication of T-cell prolymphocytic leukemia (T-PLL). We describe a case of T-PLL presenting with symptomatic infiltration of the brain that was histopathologically proven by stereotactic brain biopsy. We emphasize the importance of rapid diagnosis and immediate treatment for patients presenting with CNS involvement and a history of leukemia or lymphoma.