Giant appendiceal mucocele as a first manifestation in a patient with silent ulcerative colitis: A case report

Appendiceal mucocele (AM) is a rare lesion found in only 0.3% of all appendectomies and it is characterized by distention of the appendix by the accumulating intraluminal mucinous material. Four main histopathological subtypes of appendiceal mucocele has been described including: retention cyst, mucosal hyperplasia, mucinous cystadenoma, and cystadenocarcinoma. We report a case of 48-year-old middle eastern female, previously healthy, presented to the primary health center with right iliac fossa discomfort, and referred to our hospital for further evaluation. Contrast enhanced computed tomography of the abdomen and pelvis and focused ultrasonography over the right iliac fossa showed the characteristic CT and sonographic appearance of appendiceal mucocele. An additional incidental note of lack of colonic haustral pattern involving the rectum and descending colon was noted on abdominal CT raising the suspicion of Ulcerative Colitis which was then confirmed by colonoscopy and histopathology. Although no causal relationship between appendicular mucocele and inflammatory bowel disease has been established yet and few case reports had reported appendicular mucocele in patients with ulcerative colitis, close surveillance in these patients, and early recognition of the characteristic imaging features is crucial in preventing dreadful complications like pseudomyxoma peritonei.