Leiomyosarcoma of the pancreas: report of a case.

Leiomyosarcoma of the pancreas is a rare neoplasm, with only 34 reported cases in the literature. We encountered a rare case of leiomyosarcoma of the pancreas, treated successfully by surgery. A 41-year-old woman was referred to our hospital for further examinations of a pancreatic tumor. Imaging studies demonstrated a solid and lobular mass, about 4 cm in diameter, in the body of pancreas. This mass had a nonuniform content and was encapsulated. We performed distal pancreatectomy and splenectomy for an assumed diagnosis of invasive ductal carcinoma. Macroscopically, a sagittal section of the operative specimen showed a well-circumscribed yellowish-white mass without any cystic changes. Immunohistological examination revealed that α-smooth muscle actin, desmin, and vimentin were positive, and the labeling index of MIB-1 was 50% or more. Based on these findings, we confirmed a diagnosis of leiomyosarcoma originating from the pancreas. During 14 months of follow-up to date, there has not been any evidence of local recurrence or distant metastasis.