A hidden threat: incidental diagnosis of goblet cell carcinoma of the appendix

Goblet cell carcinoma (GCC) of the appendix is an exceptionally rare and distinct appendiceal neoplasm characterized by mixed features of both neuroendocrine tumors and adenocarcinomas. Its insidious presentation, frequently mimicking more common conditions like acute appendicitis, contributes to diagnostic challenges and highlights its rarity. We present the case of a 70-year-old female who presented to clinic with right-sided abdominal aching and intermittent nausea. Workup revealed colon nodule and she was taken to the operating room for colon resection. An incidental appendectomy was performed given the abnormal appearance of her appendix intraoperatively. Pathology revealed high grade GCC of the appendix, and she was taken back for a laparoscopic right hemicolectomy during the same admission. This case underscores the profound rarity of appendiceal GCC, with an estimated incidence of 0.01 to 0.05 per 100 000 individuals. The diagnostic ambiguity necessitates a high index of suspicion and meticulous pathological review.