Malignant pseudomyxoma peritonei of colonic origin. Natural history and presentation of a curative approach to treatment.

Pseudomyxoma peritonei is an unusual malignancy arising from the goblet cells of the large bowel or appendix. Its characteristic clinical features are low histologic grade of malignancy and widespread dissemination throughout the abdominal cavity. In a clinical study of 14 patients, the most common initial symptoms were abdominal distention or right lower quadrant pain suggestive of appendicitis. All patients underwent radical procedures in an attempt to surgically remove all gross disease from the abdomen. Six patients had small-bowel obstruction and five of these had bowel function restored. All of eight patients had relief from bulky intra-abdominal tumors. Six cycles of intraperitoneal 5-FU and three doses of mitomycin C were used following cytoreductive surgery in seven patients. Five of these seven patients are disease free following staging by celiotomy with two- to four-year follow-up. This new treatment strategy, designed to cure some patients with pseudomyxoma peritonei, has given favorable results in a disease that previously had a uniformly lethal outcome.