Site of Biopsy and Its Accuracy in Preoperative Diagnosis of Superficial Nonampullary Duodenal Epithelial Tumors: Retrospective Study

<b>Background/Objectives:</b> As endoscopy is increasingly being used to diagnose superficial nonampullary duodenal epithelial tumors (SNADETs), there is a growing need for their early detection and minimally invasive treatment. This study investigated the diagnostic accuracy of biopsy specimens for SNADETs. <b>Methods:</b> We conducted a retrospective analysis of clinicopathologic data from 98 patients with SNADETs who had undergone endoscopic resection. The presurgical diagnosis, based on biopsy specimens, was compared with the histological diagnosis of the excised specimens. <b>Results:</b> Herein, preoperative biopsies were performed on 98 SNADETs specimens from 91 patients. Of the 68 adenomas and 30 carcinomas, 22.4% adenomas were later found to be carcinomas. Carcinoma biopsy diagnosis sensitivity, specificity, and accuracy were 54.6%, 80.0%, and 71.4%, respectively. Biopsy accuracy for carcinoma differed significantly by location to the papilla of Vater (<i>p</i> = 0.0455). The preoperative biopsy diagnostics' sensitivity, specificity, and accuracy for oral and anal carcinomas to Vater papilla were 69.2%, 92.0%, and 84.2% and 42.1%, 73.2%, and 63.3%, respectively. <b>Conclusions:</b> The diagnostic accuracy of biopsy for SNADETs was low; however, it was higher on the oral side than the anal side of the papilla of Vater. The biopsy of duodenal lesions should be performed after an endoscopic examination, considering their location and reducing the risks of fibrosis.