Ruptured giant mucocele of the appendix with pseudomyxoma peritonei

DIAGNOSIS Ruptured giant mucocele of the appendix with pseudomyxoma peritonei The differential diagnosis includes enteric duplication cyst, ovarian cyst, mesenteric cyst, hydrosalpinx, lymphocele, abscess, hematoma, etc.1, 2 ,3, 4 IMAGING FINDINGS A computed tomography (CT) scan of the abdomen with oral and intravenous contrast showed a moderately large mass lesion with thin enhancing walls in the right iliac fossa region (Figure 1). Mucoceles can be divided into 3 categories: (1) retention mucocele with normal/hyperplastic appendiceal mucosa; (2) mucinous cystadenoma with neoplastic epithelium similar to that seen in villous adenomas and adenomatous polyps; and (3) mucinous cystadenocarcinoma with neoplastic epithelium similar to that seen in adenocarcinoma of the colon.2,5 Rupture of the mucocele may result in pseudomyxoma peritonei, which is characterized by implantation of mucinous epithelium on the peritoneum and mucus accumulation within the peritoneal cavity, often leading to adhesions and intestinal obstruction.2 Accurate pre-operative diagnosis of unruptured mucocele of the appendix is extremely important, since it may reduce the possibility of rupture and peritoneal contamination during resection.1,2 A typical imaging finding is a cystic mass in the expected region of the appendix.