2005 Volume 19 Issue 4 Pages 220-223
We encountered a 3-year-old boy with isolated left testicular relapse of acute myelogenous leukemia (AML : FAB classification M5a) that occurred 11 months after the completion of chemotherapy. The bone marrow specimen revealed a massive infiltration of monoblasts with chromosomes involving t (9; 11) (p22; q23) at the initial diagnosis. At the time of recurrence, histopathological findings on biopsied testis mimicked those of non-Hodgkin's lymphoma (NHL); however, MLL/AF9 chimera mRNA was detected from blasts of testis by reverse transcription-polymerase chain reaction (RT-PCR). On the basis of this finding, he was diagnosed as having testicular relapse of acute myelogenous leukemia. Although a bone marrow specimen revealed infiltration of leukemic cells and monoblasts were detected in cerebrospinal fluid, he has again been in remission with AML-99 protocol. As testicular relapse in AML is extremely rare, it was difficult for us to diagnose this case. It is suggested that RT-PCR is useful to diagnose overt testicular relapse of AML, even though histopathological findings mimic those of NHL.
