Appendiceal Mucocele

Abstract

Case Presentation: A 53-year-old male underwent a colonoscopic examination after a single episode of small-volume hematochezia. Colonoscopy revealed sigmoid diverticulosis and a 2 × 2 cm friable mass in the cecum, obscuring the appendiceal orifice. [figure 1] Mucosal biopsies from the mass revealed mild, chronic inflammation, with no evidence of malignancy. Contrast-enhanced CT scan of the abdomen and pelvis demonstrated a fluid filled appendix, and a tubular mass with an attenuating rim and a low attenuation center at the base of the appendix; the mass appeared to prolapse into the cecum. The remainder of the abdomen and pelvis appeared normal. Despite the surface biopsies, because of the concern that this mass could still be a malignant lesion, surgical resection was undertaken.FigureLaparoscopic resection of the cecum and terminal ileum was performed. Pathology revealed a chronically inflamed appendix containing a large mucus plug, consistent with a benign mucocele of the appendix. Six of 6 regional lymph nodes were benign. Discussion: An appendiceal mucocele typically describes a dilated, mucin-filled appendix. Patients may present with RLQ abdominal pain, bleeding, or a palpable abdominal mass, with or without obstructive symptoms. Alternatively, a mucocele may be an incidental operative finding. More overt clinical presentations tend to be associated with malignant processes. An association with synchronous malignancy, particularly colonic, has been established. The underlying pathology associated with appendiceal mucocele includes cystadenoma, cystadenocarcinoma, adenocarcinoma, or a benign mucin-filled cyst. The distinction between benign and malignant mucocele is difficult to establish preoperatively, thus surgical resection is recommended. Rupture of a mucinous cystadenoma or cystadenocarcinoma can occur, and may result in pseudomyxoma peritonei. In expert hands laparoscopic resection can be successful, although open resection for appendiceal mucocele is generally recommended, in order to avoid potential spillage and peritoneal seeding.