Testis : Leukemia
Leukemic infiltrates are commonly found on autopsy in the testes of patients with acute leukemia (40% to 65% of cases) and chronic leukemia (20% to 35%). Testes are a sanctuary site and frequently involved bilaterally in children with acute lymphoblastic leukemia. Testicular biopsies reveal leukemic infiltrates during remission in 5% to 10% of patients and are a predictor of subsequent relapse. In rare instances, leukemia may initially present in the testis. Leukemic testes are usually not enlarged. Infrequently, there may be testicular enlargement or induration. Microscopically, the pattern of infiltration is interstitial, like lymphomas. The neoplastic cells have scant cytoplasm and a basophilic appearance. It may not be possible to distinguish between leukemias and lymphomas without knowing the peripheral blood and bone marrow status. This image shows acute lymphoblastic leukemia in a prepubertal testis (higher magnification of the previous image).