Statistics from Altmetric.com
A 70-year-old multiparous woman was diagnosed with an ovarian tumour at a local obstetrics and gynaecology clinic with abdominal pain that started 2 weeks prior and was transferred to our hospital.
A movable mass as large as the woman’s fist was palpated in the right adnexa on pelvic examination. Pelvic ultrasonography showed a 9×5×4 cm well-defined mixed echogenic mass in the right pelvic cavity. Contrast-enhanced abdominal CT showed a 9×5×4 cm well-defined solid cystic mass with low signal intensity in the right ovarian fossa (figure 1).
Tumour markers were within normal limits (CA125: 13.1 U/mL and CA19-9: 10.63 U/mL).
Under general anaesthesia, exploratory laparoscopy was performed on suspicion of ovarian tumour. The uterus and both adnexa were normal. The mass was located near the right ovarian fossa, but it was an oval-shaped giant cyst originating from the appendix. Neither enlargement of lymph nodes around the mass nor metastasis was found. We removed the mass carefully through the endobag after complete surgical resection (figure 2). No major intraoperative complications were noted.
Based on gross findings, the appendix showed an oval-shaped cystic expansion filled with thick mucus. Microscopic finding revealed that the appendix was composed of a mucinous cystic lesion with mucin containing a tall columnar cell lining; hence, the patient was diagnosed with a benign mucinous tumour of the appendix (figure 3).
The patient made an uneventful postoperative recovery and was discharged home on the fourth postoperative day.
Appendiceal mucocele is a benign or malignant tumour that arises in the appendix and refers to a condition of expanded appendix with a lumen full of abnormal mucoid substances.1 2
The incidence is relatively rare at 0.2%–0.3% in patients who had appendectomy, and cases preoperatively diagnosed in early stage are known to be very rare.3
Appendicel mucocele may mimic other adnexal lesions such as tubo-ovarian abscess, hydrosalpinx and ovarian mucinous tumour.4 5
Approximately 25% of cases of mucocele of the appendix are symptomless and identified by chance.
Most cases are found during examinations due to lower abdominal pain.
Delayed diagnosis due to the abovementioned reasons or intraperitoneal rupture due to careless practice during surgery may result in complications, including pseudomyxoma peritoneum.
Appendiceal mucocele yields a favourable prognosis in cases without complications, such as pseudomyxoma peritonei. In addition, it is rarely malignant, and a differential diagnosis is important given that it appears in the form of an intra-abdominal mass or submucosal tumours in the cecum.
Appendicel mucocele is benign or malignant tumour that arises in the appendix.
Approximately 25% of mucocele of the appendix are symptomless and are found by chance and most cases are found during examinations due to lower abdominal pain.
Rupture during the surgery may cause pseudomyxoma peritoneum, and background knowledge on such case is required and careful removal is essential.
Contributors All persons who meet authorship criteria are listed as authors, and all authors certify that they have participated sufficiently in the work to take public responsibility for the content, including participation in the concept, design, analysis, writing or revision of the manuscript. Furthermore, each author certifies that this material or similar material has not been and will not be submitted to or published in any other publication before its appearance in the BMJ case reports. Authorship contributions: Category 1: Conception and design of study: SYL and DHC. Acquisition of data: SYL and DHC. Analysis and/or interpretation of data: SYL and DHC. Category 2: Drafting the manuscript: SYL and DHC. Revising the manuscript critically for important intellectual content: SYL and DHC.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Disclaimer Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.