Follicular cholangitis and pancreatitis – clinicopathological features and differential diagnosis of an under‐recognized entity

Abstract

Zen Y, Ishikawa A, Ogiso S, Heaton N & Portmann B (2012) Histopathology 60, 261–269 Follicular cholangitis and pancreatitis – clinicopathological features and differential diagnosis of an under‐recognized entity Aims: Biliary and pancreatic ductal systems can be involved in several lymphoplasmacytic inflammatory conditions, including primary sclerosing cholangitis, immunoglobulin G (IgG) 4‐related cholangitis and autoimmune pancreatitis. Here in we describe an unusual pancreatocholangitis whose features suggest a distinct disease entity. Methods and results: The study group consists of five adult patients, three with predominantly hilar bile duct stricture and two with a bulky pancreatic head. Four patients were treated surgically for suspected malignancy and one patient underwent liver transplantation with a clinical diagnosis of primary sclerosing cholangitis. Histological examination revealed extensive lymphoplasmacytic inflammation centred on large biliary or pancreatic ducts. Many lymphoid follicles with germinal centres were noted around the affected ducts. Whipple specimens from two patients with a pancreatic head mass showed similar follicular inflammation histologically around bile ducts. In contrast to autoimmune pancreatitis, diffuse infiltration of IgG4⁺ plasma cells, granulocytic epithelial lesions and obliterative phlebitis were not identified. The postoperative course was uneventful, without evidence of recurrence (follow‐up period 17–65 months). Conclusions: This study suggests that a disease entity which can be named follicular cholangitis and pancreatitis exists and may be under‐recognized. The disease mainly affects the hilar bile ducts and pancreatic head in adults.