Papillary carcinoma of the gallbladder

Papillary (exophytic) growth in the gallbladder covers two related entities that the WHO classification (5th edition, 2019) separates. The intracholecystic papillary (or papillary-tubular) neoplasm, ICPN, is a mass-forming preinvasive neoplasm of 1 cm or more: in the defining series of 123 cases patients were mostly women (2 to 1), mean age 61, median size 2.2 cm, half presenting with pain and half found incidentally, and gallstones were present in only 20 percent, far below their frequency in ordinary gallbladder cancer (Adsay 2012). Papillary gallbladder carcinoma proper is an invasive adenocarcinoma with complex papillary architecture. Akita and colleagues, applying strict criteria to 75 cancers, found that ICPNs (7) showed gross mucin hypersecretion in 43 percent, had no lymphovascular invasion or nodal metastasis, and were less advanced than either papillary (24) or non-papillary (44) carcinomas, in which those features occurred in 13 to 59 percent; exome sequencing also separated the groups (Akita 2019). Cancer Research UK describes papillary adenocarcinoma as less likely to spread to the liver and nearby nodes and as having a better outlook than most other types.

What differs in treatment: the polypoid growth means these lesions are often visible on ultrasound and removed as polyps of 10 mm or more under the European polyp guideline, sometimes while still preinvasive; once invasive they are staged and treated as adenocarcinoma. A papillary lesion can be difficult to tell from adenomyomatosis or a cholesterol polyp on imaging, and the pathology report should say whether invasion is present and how deep (Adsay 2012; Foley 2022).