Osteosarcoma after bone marrow transplantation for acute lymphoblastic leukemia

A male patient initially diagnosed with acute lymphoblastic leukemia at age 9 years received chemotherapy (total body irradiation, 12 Gy) followed by allogeneic bone marrow transplantation. Since then, he had been in complete remission. Three years after the bone marrow transplantation, he complained of increasing pain in the right knee. Radiological and histological examinations led to a diagnosis of conventional osteosarcoma. We performed intensive chemotherapy and wide local excision of the osteosarcoma. Intensive chemotherapy was accomplished as planned, although recovery from myelosuppression was delayed during some cycles. Polymerase chain reaction-single-strand conformation polymorphism analysis revealed a p53 gene mutation in exon 7 in the tumor cells, but not in skin or blood cells. This is an extremely rare case of osteosarcoma after bone marrow transplantation.