Torsion of Appendiceal Mucinous Neoplasm: A Rare Cause of Right Lower Quadrant Abdominal Pain.

Appendiceal mucinous neoplasms are rare, and torsion of the appendix is exceptionally uncommon. Rupture of an appendiceal mucinous neoplasm can lead to pseudomyxoma peritonei, a condition with high morbidity. We present the case of a 64-year-old male patient with five days of right lower quadrant abdominal pain. Cross-sectional imaging of the abdomen and pelvis revealed a five-centimeter-long, tubular, ring-enhancing lesion, concerning for a mucocele. Intraoperatively, a 360-degree appendiceal torsion was identified, prompting conversion from laparoscopy to laparotomy to avoid mucocele rupture. Pathology confirmed a low-grade appendiceal mucinous neoplasm with negative margins. The patient recovered uneventfully and remained asymptomatic at follow-up. This case underscores the deceptive presentation of a torsed appendiceal mucocele and highlights important technical considerations for optimal operative management of this pathology.