The first report of familial adult T-cell leukemia lymphoma in the United States.

Two patients, a daughter and her father, developed the acute type of adult T-cell leukemia/lymphoma (ATLL) within a 3-month period. Antibodies against HTLV-I have been found in both wives of the father. The second wife acquired the infection from her husband within 3 years of marriage. The patients described represent the first cases of familial ATLL in the United States. ATLL continues to be frequently misdiagnosed in the United States. A positive family history consistent with this disease in a patient with a lymphoid malignancy may be a helpful clue for earlier diagnosis.