MUCOCELE OF THE APPENDIX: A CASE REPORT

Case Presentation MJS, a 67-year-old male, was referred to the coloproctology outpatient clinic due to abdominal pain for several months, without changes in bowel habits, bleeding, pruritus, or weight loss. On physical examination, a palpable mass was noted in the hypogastrium. Colonoscopy revealed a polyp (polypectomy), and abdominal ultrasound showed an oval lesion to the right of the bladder. A subsequent pelvic MRI showed an expansive, oval lesion with lobulated contours, hypointense on T1, hyperintense on T2, and peripheral contrast enhancement, measuring approximately 7.9 × 4.3 × 5.0 cm, possibly corresponding to an appendiceal mucocele. As a result, a right colectomy was performed without complications. Intraoperatively, the lesion had a cleavage plane with the bladder and involved the distal ileum. The pathological examination indicated a low-grade mucinous neoplasm of the cecal appendix with moderate atypia, confined to the appendiceal mucosa, with free surgical margins, and no involvement of the colon or ileum. Lymph nodes were also free of neoplasia (0/30). Pathological staging: pTis, pN0. The patient, 60 days after surgery, is recovering well, with preserved bowel habits, no complaints, and no indication for adjuvant treatment. Awaiting immunohistochemical results of the surgical specimen.

Discussion Mucocele is the term used to describe the gelatinous tumor of the vermiform appendix, occurring due to the abundant production of mucus in the lumen or chronic obstruction, leading to its accumulation. It is a rare condition that affects 0.1-0.4% of the population and presents in three types: Type I, benign; Type II, mucinous cystadenoma, covered by neoplastic epithelium; and Type III, appendiceal cystocarcinoma, a malignant and aggressive neoplasm. Its treatment is surgical: appendectomy for Types I and II, and right colectomy for Type III. In cases of diagnostic uncertainty or tumor invasion, or in the case of larger tumors, colectomy is preferred. It is crucial not to rupture the structure during specimen removal to prevent disease dissemination to the peritoneum—risk of pseudomyxoma peritonei.

Conclusion The presented case highlights what is expected of an appendiceal mucocele: diagnosis through incidental finding and nonspecific abdominal pain. Therefore, understanding the pathology and its nuances in the presence of clinical suspicion is essential, as it can lead to negative outcomes if diagnosed late or managed inappropriately.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
25 April 2025