Lymphomas and leukemias in the relatives of patients with mycosis fungoides.

Of 526 consecutive patients with cutaneous T-cell lymphomas, 21 had first-degree relatives with lymphoproliferative or hematopoietic malignancies. Twenty-nine such tumors occurred in the 21 kindreds. Hodgkin's disease accounted for one-third of this total, with various leukemias (11 cases), non-Hodgkin's lymphoma (five cases), and multiple myeloma (three cases) comprising the remainder. These data suggest that genetically-determined immunoregulatory abnormalities may represent a shared pathway of oncogenesis in diverse lymphoproliferative and hematopoietic malignancies.