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 investigation 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 original 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.