Primary extraskeletal osteosarcoma of small bowel mesentery presenting with acute bowel obstruction.

Extraskeletal osteosarcoma of the small bowel mesentery is an exceedingly rare condition. It is an aggressive malignant neoplasm of mesenchymal origin characterized by osteoid formation. Final diagnosis is often made by histopathological analysis. However, we believe that prospective radiological diagnosis may be possible through careful analysis of densities (ossification) within the mesenteric mass. To the best of our knowledge, there is no current literature describing the radiological approach to making a prospective diagnosis of this condition. We present the 12th case of extraskeletal osteosarcoma worldwide and describe a radiological approach that is potentially useful in making a prospective diagnosis.