Primitive neuroectodermal tumor of bone as a second malignant neoplasm in a child previously treated for acute lymphoblastic leukemia.
PURPOSE: Although rare, second malignant neoplasms (SMNs) are a devastating consequence of successful treatment of childhood cancer. The 15-year estimated risk of developing a second malignant neoplasm after treatment of childhood acute lymphoblastic leukemia (ALL) is 2.5%. Most of these neoplasms are central nervous system tumors. The risk of secondary acute myeloid leukemia has been negligible in most treatment regimens. Here, we report the first case of a primitive neuroectodermal tumor (PNET) in a patient treated for ALL. PATIENTS AND METHODS: A 15.7-year-old girl developed pain in her left leg 7 years after diagnosis of low-risk ALL. Imaging studies revealed lytic lesions in her left proximal tibia and several vertebra as well as metastatic nodules in both lungs. RESULTS: Immunocytochemical and molecular analyses led to the diagnosis of PNET. The treatment of this SMN was composed of combination chemotherapy with hematopoietic growth factor support and radiotherapy to the primary lesion and affected spine. The tumor recurred 5 months after the completion of treatment, and the patient is now undergoing salvage therapy composed of chemotherapy and radiotherapy. CONCLUSIONS: To our knowledge, this is the first report of PNET as an SMN after successful treatment of ALL.