A Rare Case of a High-Grade Appendiceal Mucocele Causing Colocolonic Intussusception.

Appendiceal mucoceles are rare, accounting for less than 0.3% of all appendiceal pathology. High-grade appendiceal mucinous neoplasms (HAMNs) are a specific subtype with a significant risk for malignancy and poor prognosis, representing approximately 20% of appendiceal mucinous tumors. Complications of an appendiceal mucocele include rupture, malignancy, intestinal obstruction, and, rarely, colonic intussusception. Here, we present the case of a 31-year-old female with an asymptomatic appendiceal mucocele leading to intussusception. Following a computed tomography abdominal pelvis (CTAP) scan confirming the diagnosis, she underwent an emergency right hemicolectomy. Histopathology revealed a high-grade mucinous neoplasm. This report highlights the diagnostic challenges, surgical management, and histopathological findings of this rare entity.