Gastric leiomyosarcoma mimicking a cystic tumor at the pancreatic tail--one case report.

A 73 year-old female patient suffered from anemia and a palpable abdominal mass. Abdominal ultrasonography and magnetic resonance imaging revealed a lesion with papillary excrescences at the pancreatic tail. Endoscopic retrograde cholangiopancreatography showed a normal pancreatic duct, but a small submucosal tumor was found in the stomach incidentally. Laparotomy disclosed an exophytic tumor arising from the submucosal layer of the stomach. Pathology revealed a gastric leiomyosarcoma with remarkable liquefaction and cystic change. Gastric leiomyosarcoma can be so necrotic as to be mistaken for a cystic tumor. It is critically important to differentiate the peripancreatic cystic lesion because the treatment strategy is totally different.