Mucocele of the appendix: An unusual cause of lower abdominal pain in a patient with ulcerative colitis. A case report

The authors report the case of a 60-year-old male patient (B.S.). In November 2001 he developed intestinal symptoms: bloody diarrhea and abdominal pain. Colononoscopy and biopsy established the diagnosis of ulcerative colitis (proctosigmoiditis). The disease activity was moderate at the beginning. No significant laboratory alterations were found (including CEA, CA19–9), mesalazine was started orally. He was in remission until November 2003, when he was admitted to our Outpatient Clinic with upper and right lower abdominal pain and bloody diarrhea. Colonoscopy found proctosigmoiditis with moderate activity, gastroscopy revealed chronic gastritis, laboratory data were normal. Treatment was amended with mesalazine clisma and methylprednisolone (16mg), orally. Symptoms ameliorated, however, right lower abdominal pain persisted. US and CT examination demonstrated a pericaecal cystic mass (11×3.5cm). The final diagnosis of mucocele was based on fine needle biopsy and cytology. The patient underwent right hemicolectomy and excision of the mucocele. He recovered well; final histology revealed cystadenoma of the appendix. Follow-up was started: the patient is now free of symptoms. Although primary adenocarcinoma of the appendix is uncommon, the authors emphasize that preoperative diagnosis of an underlying malignancy in a mucocele is important for patient management, however, it is difficult on imaging studies and fine needle biopsy.