Intra-abdominal metastasis in osteosarcoma: survey and literature review.

Extrapulmonary metastasis, particularly abdominal metastasis from osteogenic sarcoma, are rare and generally appear as a solid mass of calcification as the primary tumor. The aim of this case report is to document the incidence, characteristics, treatment, and prognosis of abdominal metastasis in osteosarcomas in a single institution and to review the literature. From September 1989 to December 2002, 94 children ≤16 years of age with osteosarcomas were diagnosed and treated in the Division of Pediatric Oncology, Oncology Institute, Istanbul University. Patients with abdominal metastasis were assessed. Two girls of 94 patients (2.1%) with osteosarcoma developed abdominal metastasis. One had pulmonary metastasis at diagnosis and the other had developed lung metastasis 15 months after diagnosis. They developed abdominal metastasis 4 and 3 years after diagnosis during therapy or relapse at a median duration of 16 months (1-70 months) from initial diagnosis. All patients had metastasis to various sites, mostly lung, at the time the abdominal metastasis were detected. Treatment included surgery, chemotherapy, and radiotherapy in one and only surgery in the other patient. Both patients died at a median time of 4 months (2-6 months) from the time of abdominal metastasis with progressive disease. Abdominal metastasis in osteosarcoma is a rare event, but abdomen should be investigated in case of recurrence from osteosarcoma. The outcome for these patients is dismal in this series and in the literature.