Incidence and Predictors of Neoplastic Diagnosis in Patients with a Clinically Abnormal Appendix

Appendiceal abnormalities, beyond typical acute appendicitis, are occasionally detected on imaging or endoscopy, leading to surgical evaluation. How often these reflect an underlying neoplasm, however, remains unclear. This study aimed to determine the incidence and associated findings of neoplastic disease in this setting.

Patients undergoing diagnostic appendectomy following abnormal findings in endoscopy or imaging at an academic cancer center were reviewed (2011-2021). Patients with preoperative diagnoses of acute appendicitis without a "suspicious" lesion, peritoneal carcinomatosis, or known malignancy were excluded. Radiographic, biochemical and colonoscopic findings were compared between neoplastic and non-neoplastic appendiceal pathology.

A total of 132 patients were identified (mean age 64 years, 52% female). Neoplastic disease was found in 68 (52%) cases and was more common in patients with cystic mass (77%, p < 0.001), calcifications (75%, p = 0.02), or dilated appendix (63%, p < 0.001), and less common in patients with thickened wall (28%, p = 0.001) or inflammation (6%, p < 0.001) on imaging. Following appendectomy, 2 (1.5%) patients with adenocarcinoma required right hemicolectomy and chemotherapy and 12 (9.1%) required surveillance only, while the remainder required no further follow-up. Three risk groups were defined: high (presence of cystic mass), with a 77% incidence of neoplasm; low (inflammatory changes without a cystic mass), with 0% incidence; and moderate (not meeting criteria for high or low risk), with 42% incidence.

Neoplastic pathology is common in patients referred to a cancer center with appendiceal abnormalities on imaging or endoscopy. These findings support diagnostic (and, in most cases, therapeutic) appendectomy as an effective management strategy in this context.