Diffuse Intracystic Papillary Neoplasm Indistinguishable from Gallbladder Cancer: A Case Report

This report describes a patient who underwent resection for an intracystic papillary neoplasm (ICPN) classified by the World Health Organization in 2010 as a pre-cancerous or early cancerous tumor of the gallbladder. The patient was a 70-year-old Japanese woman who was hospitalized for hepatic dysfunction and jaundice. Various imaging tests revealed multiple papillary tumors, present mainly in the gallbladder lumen as well as infiltrating the intra- and extra-hepatic bile ducts and the liver. Advanced gallbladder cancer was suspected. The patient underwent extended right hepatectomy and resection of the extrahepatic bile duct and regional lymph nodes along with hepatico-jejunostomy. However, the gallbladder tumor was diagnosed immuno-histopathologically as intestinal-type ICPN with high-grade dysplasia. ICPN has been described as a gallbladder papilloma (papillomatosis), comparable to benign gallbladder lesions. To date, however, there have been no reports of patients with multiple tumors in the gallbladder lumen resulting in an ICPN of large diameter. As ICPN is regarded as a pre-cancerous or early cancerous tumor of the gallbladder, the method of diagnosis and histopathological classification require standardization.