PRIMITIVE NEUROECTODERMAL TUMOR OF BONE AS A 2ND MALIGNANT NEOPLASM IN A CHILD PREVIOUSLY TREATED FOR ACUTE LYMPHOBLASTIC-LEUKEMIA

Purpose: Although rare, second malignant neoplasms (SMNs) are a devast ating consequence of successful treatment of childhood cancer. The 15- year estimated risk of developing a second malignant neoplasm after tr eatment of childhood acute lymphoblastic leukemia (ALL) is 2.5%. Most of these neoplasms are central nervous system tumors. The risk of seco ndary acute myeloid leukemia has been negligible in most treatment reg imens. Here, we report the first case of a primitive neuroectodermal t umor (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 pr oximal tibia and several vertebra as well as metastatic nodules in bot h lungs. Results: Immunocytochemical and molecular analyses led to the diagnosis of PNET. The treatment of this SMN was composed of combinat ion chemotherapy with hematopoietic growth factor support and radiothe rapy to the primary lesion and affected spine. The tumor recurred 5 mo nths after the completion of treatment, and the patient is now undergo ing salvage therapy composed of chemotherapy and radiotherapy. Conclus ions: To our knowledge, this is the first report of PNET as an SMN aft er successful treatment of ALL.