A prospective study of discrepancy between clinical and pathological diagnosis of appendiceal mucinous neoplasm

PURPOSE: Appendiceal tumoral lesions can occur as benign, malignant, or borderline disease. Determination of the extent of surgery through accurate diagnosis is important in these tumoral lesions. In this study, we assessed the accuracy of preoperative CT and identified the factors affecting diagnosis. METHODS: Patients diagnosed or strongly suspected from July 2016 to June 2019 with appendiceal mucocele or mucinous neoplasm using abdominal CT were included in the study. All the patients underwent single-incision laparoscopic cecectomy with the margin of cecum secured at least 2 cm from the appendiceal base. To compare blood test results and CT findings, the patients were divided into a mucinous and a nonmucinous group according to pathology. RESULTS: The total number of patients included in this study was 54 and biopsy confirmed appendiceal mucinous neoplasms in 39 of them. With CT, the accuracy of diagnosis was 89.7%. The mean age of the mucinous group was greater than that of the nonmucinous group (P = 0.035). CT showed that the maximum diameter of appendiceal tumor in the mucinous group was greater than that in the nonmucinous group (P < 0.001). Calcification was found only in the appendix of patients in the mucinous group (P = 0.012). Multivariate analysis revealed that lager tumor diameter was a factor of diagnosis for appendiceal mucinous neoplasm. CONCLUSION: The accuracy of preoperative diagnosis of appendiceal mucinous neoplasms in this study was 89.7%. Blood test results did not provide differential diagnosis, and the larger the diameter of appendiceal tumor on CT, the more accurate the diagnosis.