Ampulla of Vater biopsies: A retrospective 10-year, single-institution study.

Endoscopic biopsies from the ampulla of Vater are challenging due to specimen sampling limitation, small size, interventional artifacts, and the nature of local complex anatomy. We retrospectively reviewed 318 in-house ampulla of Vater biopsy specimens from 252 patients over a 10-year period. The biopsy findings were compared to those in subsequent biopsy and/or resection specimens. Of the 318 biopsy cases, 104 (32.7 %) cases were diagnosed as adenoma (96 with low-grade dysplasia; 8 with high-grade dysplasia), 19 (6.0 %) adenocarcinomas (ampullary-12, distal bile duct-6, pancreatic-1), 5 (1.6 %) other carcinomas/tumors, and the rest were benign findings (unremarkable, ulcer and acute inflammation, reactive changes, and rare atypical cells/gland). Of the 90 cases with follow-up specimens, 55 cases (61.1 %) had concordant results and 35 (38.9 %) were discordant. Eight (22.9 %) of the 35 discordant cases had major discrepancies (benign biopsy diagnosis with malignant resection diagnosis); 27 (77.1 %) cases had minor discrepancies (normal, reactive, atypical, and dysplastic). We found that vast majority of the false negative biopsy results were due to sampling limitations. Combined biopsy and cytology specimens may help decrease the false negative rate. Careful correlation with endoscopic/cytology/clinical findings and acknowledging the limitation of the biopsy material in the pathology report are important, when malignancy is suspected but cannot be established in a small ampullary biopsy.