Primary leptomeningeal presentation of T-cell lymphoma. Report of a patient and review of the literature.

Although secondary leptomeningeal lymphoma is relatively common, primary leptomeningeal lymphoma is rare. We report a patient with the extremely unusual clinical and pathologic presentation of a primary T-cell lymphoma of the leptomeninges. Diagnosis was established by morphologic and immunologic studies of cerebrospinal fluid (CSF) and brain biopsy. The leptomeningeal lymphoma responded well to intrathecal chemotherapy and irradiation but the patient has severe residual motor paralysis. The clinical and pathological features of primary and secondary central nervous system (CNS) lymphoma are reviewed in reference to this most unusual patient.