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.