Malignant lymphoma occurring in a family

Three patients, a 57-year-old man, his 60-year-old sister, and 81-year-old mother, developed non-Hodgkin's lymphoma within an interval of 12 months. There were histologic similarities of the biopsy material from these patients, but the clinical response was variable. Two patients achieved a sustained remission, and one expired after similar chemotherapy. Studies revealed slightly decreased numbers of circulating T lymphocytes in both surviving patients, and decreased cellular reactivity to mitogens in the man. HLA typing was not conclusive; HLA haplotypes were not the same as those reported in other families with non-Hodgkin's lymphoma. Electron microscopy of biopsy material revealed no viral inclusions. Except for the familial relationship, no common etiologic factors were identified.