A 50-year-old woman presents with several months of mild right lower quadrant pain. She has never had a colonoscopy or prior abdominal operations. Her white blood cell count is normal. A CT scan of her abdomen and pelvis with intravenous contrast is shown in Figure 1. An appendiceal mucocele is suspected. She undergoes colonoscopy. Figure 2 shows bulging at the appendiceal orifice. She undergoes laparoscopy, and an enlarged appendix is identified. It is removed by dividing across normal bowel at the base of the cecum. Pathology reveals low-grade appendiceal mucinous neoplasm (LAMN) with a negative margin and no extra-appendiceal extension.