[INTRACHOLECYSTIC PAPILLARY-TUBULAR NEOPLASM: A NEW PATHOLOGY OF THE GALLBLADDER?].

The clinicopathologic characterization of tumoral intra-epithelial neoplasms of the gallbladder is fairly limited compared to that of similar tumors of the pancreatobiliary system. Until recently, pre-malignant lesions of the gallbladder were mostly reported as adenomas, which were microscopic and therefore regarded as benign and clinically inconsequential, whereas papillary lesions have been largely regarded as a papillary subtype of gallbladder invasive adenocarcinoma. In an attempt to create a unified terminology for these tumors, the term Intracholecystic papillary-tubular neoplasm (ICPN) was proposed to include all exophytic intra-epithelial tumors of the gallbladder measuring ≥1 cm under one category. A few studies which have retrospectively analyzed tumors fulfilling this category found them to be remarkable analogous to the more well-characterized intra-epithelial tumors of the pancreato-biliary system such as IPMN of the pancreas and IPNB of the bile ducts and as such they also represent an 'adenoma-carcinoma' sequence in the gallbladder. Since then a number of case series have been published which attempted to characterize the clinical and pathological features of these tumors and their relationship with invasive carcinoma. In this paper we report three cases of ICPN which represent different stages of the 'adenoma-carcinoma' sequence.