[Testicular relapse, with Ph-positive chromosome after bone marrow transplantation for acute lymphocytic leukemia]

A 25-year-old man with acute lymphocytic leukemia (ALL) had received bone marrow transplantation (BMT). Testicular relapse occurred 6 months after BMT as the first relapse, and couple of weeks later, bone marrow relapse developed. At that time, karyotypic analysis showed Ph-chromosome which was not observed before the first remission and DNA analysis revealed rearrangements of minor BCR, IgL, IgH, TCR and TCR genes. Testicular relapse often develops in ALL of children after BMT. However, some reports, including this report, indicate that testicular relapse following BMT can also occur in adults, so that the incidence of testicular relapse could be reduced either by total body irradiation (TBI) or testicular irradiation before transplantation. Incidence of Ph-positive chromosome following BMT is a key to illuminate the mechanism of the Philadelphia chromosome. Rearrangements of Ig and TCR gene can be considered as an abnormal gene rearrangement occurring at an early stage of B cell proliferation.