Extraskeletal Osteosarcoma of Colon Mimicking Carcinoma of Colon – A Rare Entity

Extraskeletal osteosarcoma is a rare malignant mesenchymal tumor which typically affects elderly patients and the commonly affected sites are extremities, retroperitoneum, mesentery, and trunk. Extraskeletal osteosarcoma arising from colon or retroperitoneum can manifest as a large mass with features of intestinal or urinary tract obstruction. Local recurrence after excision and distant metastasis are common, so regular follow-up and surveillance of such patients are advisable after excision of the primary tumor.