Intracholecystic papillary-tubular neoplasms (ICPN) of the gallbladder (neoplastic polyps, adenomas, and papillary neoplasms that are at least 1.0 cm): clinicopathologic and immunohistochemical analysis of 123 cases

123 gallbladder cases with a well-defined exophytic preinvasive neoplasm of 1 cm or more were analysed. Patients were predominantly female (2 to 1) with a mean age of 61 and a median tumour size of 2.2 cm; half presented with pain and half incidentally; gallstones were present in only 20%; radiology called almost half cancer and missed 10%. Configuration was papillary in 43%, tubulopapillary in 31% and tubular in 26%, and cell lineage biliary in 50%, gastric foveolar 16%, gastric pyloric 20%, intestinal 8% and oncocytic 6%, with hybrid patterns in 90%.

Of cases that would have qualified as pyloric gland adenoma, 88% had at least focal high-grade dysplasia and 18% invasive carcinoma. Overall 55% had an associated invasive carcinoma; extent of high-grade dysplasia, biliary or foveolar cell type and papilla formation were associated with invasion. Among systematically analysed invasive carcinomas, a tumoral intraepithelial neoplasm was detected in 6.4% (39 of 606). Three-year survival was 90% without and 60% with invasion, against 27% for pancreatobiliary-type gallbladder carcinoma, an advantage that persisted after stage matching.