Background: A case study of a presentation of a mucocele appendix, a rare condition accounting for 0.2% of appendicectomies. The case and operative management are discussed along with the possible progression to pseudomyxoma peritoneii and its differing management. Case: A 15-year-old girl had two presentations with atypical Right Iliac Fossa pain over 2 months. This was investigated with ultrasound and CT which revealed a calcified, intussusepting mucocele of the appendix. This was surgically resected with partial Right Hemicolectomy. The patient was discharged on day 3 with no complications. Discussion: The presentation, malignant potential, investigation and management of the mucocele appendix are discussed. The rare presentation of a mucocele appendix necessitates care to eliminate the risk of pseudomyxoma peritoneii. The operative management should minimise disturbance of the peritoneum in this presentation. In this case, due to an intersussepting nature a limited Right Hemicolectomy had to be performed. This is compared to the literature.