[Transformation of type T lymphoma into type B lymphoma]

A 45-year-old woman with T-cell lymphoma is reported. Enlargement of the peripheral lymph nodes was not observed. Splenectomy was performed for hypersplenism and during the operation the mesenteric and retroperitoneal lymph nodes were found to be greatly enlarged. Three years after the diagnosis of lymphoma malabsorption syndrome developed. After 5 years sudden clinical deterioration appeared, with loss of reaction to effective treatment given as yet. Conversion of the predominating lymphocyte subpopulation from T to B cells was observed owing to repeatedly done monitoring of peripheral blood lymphocytes. The pattern of the newly developed lymphoma was that of a highly malignant B-cell proliferation. The possible mechanisms of the conversion discussed by the authors include: simultaneous proliferation of B and T populations of lymphocytes, B-cell lymphoma induction by chemotherapy, and infection by Epstein-Barr virus.