label: Preinvasive Neoplasm of the Ampullary Region
label_lc: preinvasive neoplasm of the ampullary region
description: "A premalignant neoplastic and dysplastic lesion that arises from the ampulla of Vater.  It is characterized by the absence of invasion.  This category includes intestinal-type adenomas, noninvasive papillary neoplasms of pancreatobiliary type, and flat intraepithelial neoplasia."