Distal biliary obstruction with ampullary thickening and no obstructing calculi making the possibility of a neoplastic process most likely.

ERCP and biopsy were done from an obstructing ampullary mass. Examined sections revealed a portion of the duodenal mucosa showing infiltrating tumor tissue formed of solid sheets and cribriform structure lined by moderate to markedly pleomorphic malignant epithelial cells with high nucleo/cytoplasmic ratio and surrounding moderate desmoplasia. Final pathology diagnosis was ampullary mass showing infiltrating poorly differentiated adenocarcinoma (grade II-III).