Surveillance Colonoscopy Revealing Asymptomatic Low-Grade Appendiceal Mucinous Neoplasm.

Appendicular mucinous neoplasms are a collection of rare tumors with diverse clinical presentations and pathologic potential, which can cause diagnostic and therapeutic challenges. Traditionally, they are diagnosed by radiologic imaging or identified intraoperatively; however, rarely, they may be diagnosed during an endoscopic procedure. In this unusual case, we present the case of a 62-year-old Caucasian male undergoing routine surveillance colonoscopy due to a history of colonic neoplasia. During the colonoscopy, a submucosal, non-bleeding 1cm mass of benign appearance was found in the appendix. Further workup determined the mass was likely a mucocele, and surgical consultation was recommended. The patient denied any symptoms suggestive of a mucinous neoplasm prior to and during evaluation. A laparoscopic appendectomy was subsequently performed, and the histopathology report confirmed the diagnosis of a low-grade appendiceal mucinous neoplasm. The patient recovered without complications and continued to deny any symptoms during his postoperative course and follow-up care. Given their rare incidence and unpredictable nature, appendiceal mucinous neoplasms remain difficult to identify. Discovering a low-grade mucinous neoplasm in an asymptomatic patient via colonoscopy illustrates the spectrum of unique presentations and modalities for diagnosis.