MR imaging of primary pancreatic leiomyosarcoma.

Primary leiomyosarcoma of the pancreas is a rare neoplasm with only 17 reported cases in the literature. Although the ultrasonic and computed tomographic appearances have been described, the magnetic resonance features of pancreatic leiomyosarcomas have not. In this report, we describe the MR characteristics of a primary pancreatic leiomyosarcoma which was an incidental finding on ultrasound. The unenhanced T1 weighted and T2 weighted images were the most useful in tumour localization whereas the enhanced images actually obscured the tumour within the pancreas. Differentiation from the much more commonly occurring adenocarcinoma was impossible.