Appendiceal neoplasms are rare entities often discovered incidentally in patients undergoing surgery for acute appendicitis. Accurate identification is critical due to differing prognoses and management strategies. This retrospective single-center study analyzed 2802 adult patients who underwent appendectomy for suspected acute appendicitis between January 2015 and May 2025. Demographics, surgical approach, histopathological findings, and tumor characteristics were evaluated. Of the 2802 patients, 0.7% were diagnosed with neuroendocrine tumors (NETs), 0.4% with low-grade appendiceal mucinous neoplasms (LAMNs), and 0.1% with adenocarcinomas. Patients with LAMNs and adenocarcinomas were older (mean age >50 years), whereas NETs were more common in younger patients (mean age 33.5 years). Most NETs were well-differentiated, Grade 1, with Ki-67 index <3%. LAMNs showed no invasive features, though acellular mucin was present in deeper layers. Adenocarcinoma cases demonstrated high-risk features including deep invasion, positive margins, and lymphovascular involvement. Appendiceal neoplasms, though uncommon, display significant variation in age distribution, histological features, and malignant potential. Routine histopathological examination of appendectomy specimens remains essential. Our study shows that careful pathological examination of appendectomy specimens is important to detect rare but invasive tumors.
Agirman et al. (Thu,) studied this question.