Primary intraosseous rhabdomyosarcoma

We report a case of primary intraosseous pleiomorphic rhabdomyosarcoma loca ted in the pelvis of a 21-year-otd woman followed for 4 years. The lytic tu mor involved the acetabulum and the isthma with moderate extension to soft tissue. First line chemotherapy was unable to arrest tumor progression. Hem ipelvectomy with saddle prosthesis reconstruction was performed, but septic complications dictated a secondary inter-ilio-abdominal amputation. Recurr ence-free remission was achieved for 4 years, suggesting this was indeed a primary tumor. Primary intraosseous rhabdomyosarcomas are exceptional. Bone localizations generally suggest metastasis from a primary tumor often situated in an intr aperitoneal localization. When search for a primary tumor is negative, intr aosseous lesions can be considered as primary tumors warranting curative tr eatment. Radical surgical,resection is recommended within the framework of a multidisciplinary management protocol associating radiotherapy and chemot herapy to improve prognosis.