Granulocytic sarcoma of the prostate as the first manifestation of a late relapse of acute myelogenous leukemia.

We describe a 68-year-old patient who developed granulocytic sarcoma of the prostate 9 years after complete remission following successful treatment of acute myelogenous leukemia (FAB, M2). PCR analysis of bone marrow samples in first remission and at the time of relapse detected an AML1/ETO rearrangement typical for AMLs with t (8;21). The CD56 antigen was not expressed on the leukemic cells. Systemic chemotherapy led to a short-lasting regression of the tumor, but the patient subsequently developed overt bone marrow relapse and died during chemotherapy. While granulocytic sarcoma as a primary manifestation of AML is well known, as the first manifestation of relapse it appears to be very uncommon.