Intracholecystic papillary-tubular neoplasms of the gallbladder - A clinicopathological study of 36 cases.

Intracholecystic papillary-tubular neoplasms (ICPNs) account for <0.5% of all cholecystectomies. There is a lack of significant published data from the Indian subcontinent on ICPN to the best of our knowledge. The objective of the current study was to describe the clinicopathological features of ICPN of gallbladder from the departmental archives during a 5.5-year period. We also aimed to classify them into various histological subtypes and to correlate the clinicopathological parameters of ICPN with invasive adenocarcinoma. This study included 36 cases diagnosed over a period of 5.5 years (2013-2018). Clinical, radiological and histopathological data were analyzed in detail. The incidence of ICPN was 0.8%. The mean age of patients was 45.7 years with a female to male ratio of 1.3:1. Biliary phenotype was associated with invasion (p ≤0.001). Papillary pattern was present in 15 cases (41.6%) and was associated with invasion (p ≤0.001). High grade dysplasia was seen in 34 cases (94.4%), of which invasion was seen in 18 cases (50%). One case in our study also had synchronous common bile duct carcinoma. Majority (92%) of the patients were alive and well at the end of available follow-up (mean of 7 months and 25 days). ICPNs are mass forming neoplasms of the gallbladder with a slight female predominance. Biliary phenotype has an aggressive course, often associated with an invasive adenocarcinoma component. Papillary configuration of the lesion is significantly associated with an invasive component. Diligent follow-up of these lesions is warranted as they can be associated with other malignancies of the biliary system.