Restoration of normal hematopoiesis by bone marrow ablation and allogeneic marrow transplantation in a case of Hodgkin's disease therapy-related preleukemia.

Therapy-related leukemias are generally preceded by a preleukemic phase of several months duration, characterized by pancytopenia, abnormal bone marrow findings, and nonrandom chromosomal abnormalities in almost all cases. No specific therapeutic guidelines are recommended in this preleukemic phase or any other type of preleukemia; aggressive combination chemotherapy is usually withheld until the full expression of leukemia. A 22-yr-old man with therapy-related preleukemia following treatment of Hodgkin's disease received as primary treatment ablative chemotherapy followed by marrow transplantation from his histocompatible sister. At day 316, the patient is still in complete bone marrow recovery with a normal donor karyotype. In the light of the very poor results obtained with conventional chemotherapy regimens once the leukemic phase is established, we suggest that bone marrow transplantation, if undertaken before leukemic conversion, may be the treatment of choice in young adults with therapy-related preleukemia.