Figure 29

The primary tumor for pseudomyxoma peritonei is a ruptured appendiceal adenoma. Here, the mucocoele that formed as a result of excess mucus production within the appendiceal lumen is cut in cross section. The ruptured tip of the appendix is extruding a large volume of mucus into the free peritoneal cavity. This mucus contains large numbers of adenomatous epithelial cells that give rise to disseminated peritoneal adenomucinosis. The appendix stump has been tied off proximally.

Figure 30

A cross section of the dilated appendix in a patient with large volume pseudomyxoma peritonei. The lumen of the appendix contains areas that show adenomatous change. The distal portion of the appendix contains mucinous material and multiple adenomatous epithelial cells. The presence of adenomatous epithelial cells outside of the intestinal lumen establishes the diagnosis of pseudomyxoma peritonei. (H&E x 10).

Figure 31

Open midline abdominal incision in a patient with pseudomyxoma peritonei. The abdomen has been opened through a long midline abdominal incision, and the abdominal sidewalls secured with self-retaining retractors. The entire anterior portion of the abdomen is filled by the "omental cake". This extensive proliferation of mucinous tumor within the greater omentum is reliably the most extensive accumulation of adenomucinosis.

Figure 32

Small bowel sparing with pseudomyxoma peritonei syndrome. The greater omentum has been elevated away from the small bowel. A large volume of mucinous tumor heavily coats the greater omentum and transverse colon. However, the small bowel is relatively free of tumor and will not require "peritonectomy" in order to be made free of disease. This observation regarding small bowel sparing is the original one that initiated efforts to completely eradicate disseminated adenomucinosis from the peritoneal cavity. Retention of the entire small bowel in these patients means completely adequate nutrition after the acute recovery phase from surgery is over.

Figure 33

Pseudomyxoma polyp on the surface of the small bowel mesentery. Pseudomyxoma peritonei is a progression of adenomatous tissue outside of the intestinal lumen. It is well known that adenomas within the intestinal lumen are distorted over time by peristalsis into a pedunculated configuration. Likewise, pseudomyxoma deposits on the surface of the small bowel or its mesentery are moved continuously by the small bowel peristalsis. This movement results in the formation of a stalk that extends from the surface of the small bowel to the head of the polyp. Adenomatous tissue can result in pedunculated polyps inside the intestinal lumen or also on the peritoneal surface.