Primary T cell leptomeningeal lymphoma--successful treatment with systemic chemotherapy.

Primary central nervous system lymphoma (PCNSL) is rare, accounting for only 1-2% of non-Hodgkin's lymphoma, and primary isolated leptomeningeal lymphoma is even rarer. It may create a diagnostic problem, particularly when the tumor cells are of T cell lineage. We herein report a patient with primary T cell leptomeningeal lymphoma. The final diagnosis was confirmed by the cytogenetic study which revealed clonal aberration, isochromosome of long arm of chromosome 7, in the lymphoid cells from CSF. She was treated with a novel protocol of systemic chemotherapy specifically designed for the CNS lymphoma. The regimen consisted of carmustine, vincristine, high-dose methotrexate, etoposide, and methylprednisolone. A total of 5 courses were given and she was still in complete remission at the time of reporting, 21 months after the establishment of diagnosis.