Leiomyosarcoma of the pancreas. Report of a case and review of the literature.

A case of leiomyosarcoma of the pancreas, occurring in a 44-year-old male, is reported. With a preoperative diagnosis of cystadenocarcinoma, the patient underwent surgical resection of a cystic tumor in the head of the pancreas. There were no metastases noted at the time. The resected specimen was diagnosed histologically as a smooth muscle tumor originating from the pancreas. It was seemingly benign on the basis of the mitotic counts and the degree of cellular atypism. However, the tumor proved to be malignant; the patient died with metastases to the liver. The tumor at autopsy also had few mitoses (0-1/10 hpf). The previously reported cases were reviewed and the limitations of histological diagnosis in assessing malignant potential of smooth muscle tumors are discussed.