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 lowgrade 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.

Mayer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.