Preoperative diagnosis of pancreatic leiomyosarcoma.

Background: The low incidence of pancreatic leiomyosarcoma is responsible for the small number of cases correctly diagnosed preoperatively, the tumor being frequently confused with benign pancreatic lesions.

Results: We describe a symptom free 52-yr-old male bearing an abdominal mass incidentally found at physical examination. Imaging techniques revealed a nonhomogenous large mass at the head of the pancreas that dislodged the portal vein and the superior mesenteric vein. Increased metabolic activity in the tumor area demonstrated by 18F-fluorodeoxyglicose positron emission tomography scan allowed the diagnosis of a malignant lesion. The patient was operated on and a pylorus preserving pancreatoduodenectomy performed. The pathology diagnosis was a low grade leiomyosarcoma. Immunohistochemistry revealed positivity for vimentin and smooth muscle specific actin. The clinical course was uneventful after 2 yr follow-up.

Conclusion: Pancreatic leiomyosarcoma may be preoperatively diagnosed by image techniques and differentiated from benign lesions by means of fluorodeoxyglicose positron emission tomography scanning (FDGPET).