Pediatric acute lymphoblastic leukemia initially presenting with bone marrow necrosis

We report on a case of pediatric acute lymphoblastic leukemia presenting with massive bone marrow necrosis. A 4-year-old boy complained of fever and leg pain. Laboratory data revealed pancytopenia, but bone marrow examination showed only necrotic materials. About one month later, repeated bone marrow examination showed leukemic cells and the necrotic marrow had disappeared. The patient was treated with standard chemotherapy and was successfully induced to complete remission. Patients with massive bone marrow necrosis should undergo bone marrow examination repeatedly to make the correct diagnosis.