Intracholecystic papillary-tubular neoplasm (ICPN)

Adsay and colleagues grouped neoplastic polyps, adenomas and papillary neoplasms of the gallbladder measuring 1 cm or more under one heading, intracholecystic papillary-tubular neoplasm, in a 123-case series: female to male 2 to 1, mean age 61, median size 2.2 cm, gallstones in only 20%, and growth patterns papillary (43%), tubulopapillary (31%) or tubular (26%) with biliary (50%), gastric foveolar (16%), gastric pyloric (20%), intestinal (8%) and oncocytic (6%) lineages. Invasive carcinoma accompanied 55% of cases, and even lesions that would have been called pyloric gland adenomas had high-grade dysplasia in 88% and invasion in 18%. Three-year survival was 90% without invasion and 60% with it, against 27% for ordinary pancreatobiliary-type gallbladder carcinoma, an advantage that held after stage matching; among systematically analysed invasive carcinomas only 6.4% had a tumoral precursor, confirming that this is the minority route (Adsay 2012; Roa 2006 put adenomas at 0.14% of cholecystectomies). CTNNB1 mutation with aberrant beta-catenin expression has been described in incipient ICPNs. Because half present incidentally and radiology labels almost half as cancer, the practical consequence is that polyps of 1 cm or more are removed.