Imaging of pancreatic desmoid fibromatosis by endoscopic ultrasound.

Desmoid type fibromatosis (DTF) is a rare intermediate soft tissue tumor. Here we report a case of DTF located in the tail of pancreas. A 39-year-old female presented epigastric pain of 1 week duration. An abdominal magnetic resonance imaging revealed a 3.4-cm irregular contour solid mass in the tail of the pancreas that was interpreted by radiology as suspicious for a benign pancreatic tumor. Endoscopic ultrasound (EUS) showed an irregularly shaped hypoechoic, heterogeneous mass within the tail of pancreas invading the adjacent gastric wall, suggesting a diagnosis of malignant pancreatic tumor. Subsequently, surgery consisted of a distal pancreatectomy, splenectomy and combined partial resection of the stomach, was performed. The immunohistochemistry and histopathological features were consistent with a diagnosis of pancreatic desmoid type fibromatosis. EUS is very useful for visually defining the location and character of pancreatic DTF and to determine whether the major vessels and the adjacent organs are infiltrated.