Secondary monocytic leukemia with rearrangement of the MLL gene occurring during the course of adult T-cell leukemia.

In June 1994, a 39 year-old male with adult T-cell leukemia was admitted to our hospital and received combination chemotherapy including epipodophyllotoxin for approximately 1 year. The monocyte count increased gradually beginning in April 1995, accelerating to 100 x 10(9)/l in January 1996, when he was diagnosed with acute monocytic leukemia. Inv(11)(q21;q23) x 2 was recognized at that time by chromosome analysis, and rearrangement of the MLL gene was shown by Southern blot analysis. From the clinical course and subsequent examinations, the case was regarded as epipodophyllotoxin-related secondary leukemia. Recently, epipodophyllotoxin has frequently been used as a treatment agent for adult T-cell leukemia. It is valuable to note that secondary leukemia may follow even such an aggressive leukemia as adult T-cell leukemia.