Evaluation of Additional Treatment for Residual Cases After Endoscopic Papillectomy of Duodenal Ampullary Tumors

Background and Aims This study aimed to assess the prognosis and outcomes of additional treatment for residual adenocarcinoma and adenoma following endoscopic papillectomy (EP) for ampullary tumors. Methods Of 191 patients who underwent EP, 43 with adenocarcinoma or adenoma and either positive or unknown pathological margins were included. Cases with positive or unknown pathological margins and residuals on endoscopic observation after EP were defined as endoscopic residuals, and cases without endoscopic residuals were defined as pathological residuals. The outcomes between these groups were compared to evaluate additional treatment. Results A total of 12 cases of adenocarcinoma were identified, with pathological residuals in 10 cases and endoscopic residuals in two cases. Of the two cases with endoscopic residuals, one underwent additional surgical resection, while the other was observed and subsequently showed disease progression. Among the 10 cases with pathological residual adenocarcinoma, four underwent additional surgery, but no cancer was detected in the resected specimens. The remaining six cases showed no disease progression during the observation period, suggesting that pathological residual adenocarcinoma may have been completely eradicated by EP. Residual adenoma was detected in 31 cases, with pathological residuals in 20 cases and endoscopic residuals in 11 cases. Adenoma recurrence occurred in three cases, all of which were successfully managed with endoscopic treatment. Conclusions If the pathological margin is positive or unknown, additional treatment is necessary for cases with endoscopic residuals after EP. However, in the absence of endoscopic residuals, follow‐up observation may be carefully considered in selected cases with caution. Trial Registration N/A.