Testicular relapse in philadelphia chromosome positive acute lymphoblastic leukaemia

A case of Philadelphia-positive (Ph) acute lymphoblastic leukaemia (ALL) in a 40-year-old male is presented. At diagnosis, 80% of bone marrow cells were Ph. Remission with normal blood counts was achieved but the marrow became hypercellular, indicating conversion to chronic granulocytic leukaemia (GCL). The Ph clone persisted with a variable percentage of Ph cells. He developed testicular relapse 38 months from diagnosis. The patient died when engraftment with a matched unrelated bone marrow transplant failed. Molecular in-vestigation of DNA prepared from diagnostic and remission bone marrow and from testicular tissue in relapse revealed the same sized rearranged fragment of the BCR gene using a probe to the major breakpoint cluster region. This case confirms that testicular involvement due to infiltration of the testes by the orig-inal Ph leukaemic clone may occur as an unusual complication in Ph ALL. Conversion to chronic-phase GCL, a rare occurrence in Ph ALL, may have contributed to the unusually long survival.