A case of pseudomyxoma peritonei originating from duplication of the alimentary tract

Abstract

A 49-year-old male complaining of suddenly occurring left lower quadrant abdominal pain since August 15, 1992 was admitted to our hospital. By clinical examination, he was diagnosed as having a mesenteric cystic tumor. Laboratory data on admission showed a high plasma level of CEA, and CT scan showed a cystic tumor with septations located anterior to the left psoas. Findings of the operation performed on November 9, 1992 showed a primary tumor located in the mesosigmoid with wide dissemination of mucinous fluid throughout the entire peritoneal cavity from Douglas pouch to the left subphrenic space. The resected primary tumor was an egg-sized cyst containing a mass of mucinous fluid. Histological findings showed that the cystic wall had mucosa, submucosa and proper muscle similar to the adjacent colonic wall which strongly suggested this cystic tumor to be a duplication of the alimentary tract. Histological findings also showed that mucinous cystadenocarcinoma of low grade malignancy was arising from the columnar epithelium of the cystic wall, indicating a very rare malignant change of the duplication. The mucus destroys the wall of the duplication and extends outside the wall, resulting in wide dissemination of the mucinous fluid. The malignant cells were also found in the mucinous fluid throughout the peritoneal cavity. We concluded that this is a very rare case of pseudomyxoma peritonei of which the primary reason is considered to be the duplication of the alimentary tract.