Peritoneal osteosarcoma following irradiation therapy of ovarian cancer

A peritoneal osteosarcoma occurring after irradiation therapy for cystadenocarcinoma of ovary is described. Only 6 cases of postradiation extraosseous osteosarcomas have been reported and none of them have arisen within the peritoneum. The clinical presentation and histopathology of this unusual tumor is presented with a review of the literature.