[Leukemia Relapse as Granulocytic Sarcoma Beginning with Penile Localization : A Case Report].

A 57-year-old man visited the urology department with a painful mass on the dorsal side of the penis. Magnetic resonance imaging sagittal image showed a small nodule. Leukemia recurrence was suspected due to his history of treatment for acute myeloid leukemia treated with allogeneic hematopoietic stem cell transplantation. No recurrence was identified by bone marrow biopsy ; however, two months later, the recurrence of leukemia was strongly suspected because the tumor grew over time and blasts were found in the peripheral blood. A biopsy of the penile tumor and bone marrow was performed, leading to the diagnosis of granulocytic sarcoma. Patients with a history of leukemia may be preceded by a single recurrence to extramedullary organs, even if blood and bone marrow findings suggest remission.