Metastatic osteosarcoma presenting as a small-bowel polyp - A case report and review of the literature

Gastrointestinal metastases of osteosarcoma are an extraordinarily rare eve nt and, as far as we can determine, have been reported previously only 5 ti mes; these cases represent an unusual pattern of progression. We describe a 21-year-old man with an osteosarcoma of the right tibia that was removed 4 years previously. Two years later, the patient showed lung metastases. At his most recent presentation, he complained of abdominal pain, nausea, vomi ting, and anorexia. Radiologic examination revealed an abdominal mass close to the jejunum and 3 nodules in the liver. One metastasis was an ulcerated and pedunculated polypoid mass located in the mucosa of the bowel, and the other involved the entire thickness of the jejunum. This unusual phenomeno n represents an alteration in the natural history of osteosarcoma as a resu lt of increased long-term survival.