Appendiceal mucocele: a rare differential diagnosis of a cystic right adnexal mass

Abstract

Case report

We present the case of a 42-year-old woman with an incidental finding of a large right adnexal mass during pelvic ultrasound scan for a spontaneous miscarriage. Ultrasound suggested the mass was ovarian in origin and serum Ca125 was normal. Laparotomy, however, revealed normal ovaries with no ovarian pathology. The right adnexal mass was appendiceal in origin and was delivered intact with no spillage. Histology confirmed a diagnosis of mucinous cystoadenoma of the appendix.

Discussion

Pre-operative diagnosis of this condition is difficult. Various radiological tools including CT scans, MRI, and ultrasound scans have been used with poor results. Pre-operative diagnosis would be useful, as extra measures could be taken to avoid intra-peritoneal rupture during surgery with the consequent development of pseudomyxoma peritonei. For a similar reason, needle aspiration should be avoided. In malignant cases co-existing ovarian neoplasm must be excluded as this will be present in 2–24% of cases. Simple appendicectomy is curative in uncomplicated, unruptured cases.

Conclusion

Although relatively rare, appendiceal tumours should be considered in women who present to gynaecologists with a right adnexal mass.