Malignant diffuse peritoneal leiomyomatosis: A case report

Abstract

Diffuse peritoneal leiomyomatosis (DPL) is a rare condition characterized by the presence of multiple abdominal smooth muscle nodules. Malignant transformation appears to be extremely rare. This report presents the eighth case with proven malignancy. The patient is a 43 year old, Caucasian, non-pregnant female, with no history of hormonal therapy, presented with a few months old history of intermittent and increasing right lower abdominal pain. In October 1996, explorative laparatomy was performed. Innumerable subperitoneal gray-white masses with firm to rubbery consistency, varying in size from 0.2 to 11.5 cm, were found scattered over the parietal peritoneum, omentum and mesentery. Several of these nodules were removed. Their microscopic appearance was variable. Most of the lesions appeared to consist of subperitonel nodules of benign-appearing smooth muscle cells. Nevertheless, some of them showed malignant characteristics, marked cellularity, and numerous mitoses. Immunohistochemical and ultrastuctural studies proved the smooth muscle origin of the tumors. During the next few months the abdominal tumors increased in size and the patient's condition progressively deteriorated. A second laparotomy was performed in March 1997. More than 40 nodules were removed together with a small bowel segment where inflammatory fistula was found. After receiving three courses of chemotherapy, the patient refused further treatment. In December 1997, the patient was admitted to the hospital with acute abdominal pain due to ileus, and the third laparotomy was performed. This additional case indicates that DPL has a low, but definite malignant potential, and suggests that meticulous examination of histologic material and careful follow up are required.