Intracholecystic papillary neoplasm with associated invasive carcinoma, initially presenting with a palpable mass in...

An intracholecystic papillary neoplasm (ICPN) of the gallbladder is a newly established disease concept. Here, we report a case of ICPN with associated invasive carcinoma, manifesting with multiple polyps in the markedly enlarged gallbladder.

A 73-year-old female patient visited a clinic because of weight loss. A movable 15-cm mass was palpable in the right lower quadrant and she was referred to our hospital. Contrast-enhanced computed tomography (CT) showed that the gallbladder was markedly enlarged and multiple polyps were diffusely spread throughout it. ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/CT showed an abnormally high uptake diffusely on the thickened wall of the gallbladder. Thus, ICPN was diagnosed and the presence of concomitant gallbladder cancer was strongly suspected, and an open whole layer cholecystectomy was performed. Macroscopic findings showed a large number of papillary or nodular tumors diffused throughout the gallbladder. Histopathological findings showed that atypical cells formed complex papillary and cribriform structures. Because the tumor showed focal invasion to the subserosa, ICPN with associated invasive carcinoma was diagnosed.

ICPN with associated invasive carcinoma, as distinguished from the ordinary type gallbladder adenocarcinoma, was introduced in the 2019 WHO tumor classification. Individual data of its characteristics will be accumulated and further research on oncological behavior will be conducted.

We experienced a case of ICPN with associated invasive carcinoma, presenting with a palpable mass in the right lower quadrant.