Accuracy of biopsy for the preoperative diagnosis of superficial nonampullary duodenal adenocarcinoma

Background and Aims Endoscopic biopsy sampling for the diagnosis of duodenal adenocarcinoma is not perfect. We investigated the accuracy of biopsy specimen diagnoses of superficial nonampullary duodenal epithelial tumors (NADETs). Methods Clinicopathologic data were retrospectively reviewed for 95 superficial NADETs from 95 patients who underwent endoscopic resection. Preoperative diagnoses based on biopsy specimens were compared with histologic diagnoses of resected specimens. Results Among the 21 lesions with biopsy specimen diagnoses of carcinoma, 12 (57.1%) were histologically diagnosed as adenomas after resection. Among the 74 lesions with biopsy specimen diagnoses of adenoma, 15 (20.3%) were histologically diagnosed as carcinomas after resection. The duodenal biopsy specimen predicted final histologic diagnoses of carcinoma with a sensitivity of 37.5% (95% CI, 18.8-59.4), specificity of 83.1% (95% CI, 72.3-91.0), accuracy of 71.6% (95% CI, 61.4-80.4), positive predictive value of 42.9% (95% CI, 21.8-66.0), and negative predictive value of 79.7% (95% CI, 68.8-88.2). Among 61 cases considered suitable for EMR, treatment modality was converted from EMR to endoscopic submucosal dissection because of the nonlifting sign in 15 cases (24.6%). Conclusions The accuracy of duodenal biopsy sampling was relatively low. Duodenal biopsy sampling may induce unexpected fibrosis. New endoscopic modalities that can improve preoperative diagnosis yield of NADETs are eagerly awaited.