IgG4-related sclerosing lymphoplasmacytic pancreatitis and cholangitis mimicking carcinoma of pancreas and Klatskin tumour.

BACKGROUND: Autoimmune sclerosing pancreatitis is a well-known disease entity for years, particularly recognizing the difficulty in distinguishing it from malignancy. Immunohistochemical study showed that immunoglobulin IgG4 staining was positive in plasma cells of some autoimmune pancreatitis or cholangitis. The term 'autoimmune sclerosing pancreatocholangitis' was used as it was believed that they belonged to a range of disease involving both pancreas and biliary tree. It may also be part of a systemic fibro-inflammatory disease. PATIENTS AND METHODS: All the patients suffering from immunoglobulin G4 (IgG4)-related pancreatitis and cholangitis from May 2003 to September 2006 in Queen Elizabeth Hospital, Hong Kong were retrospectively studied.
RESULTS: A total of five patients with clinical diagnosis of IgG4-related autoimmune pancreatitis or cholangitis were analysed. All presented with jaundice or abdominal pain, mimicking carcinoma. Two patients had major resection, two patients were diagnosed by intraoperative biopsy and one was based on serum IgG4 level.
CONCLUSION: With the growing awareness of this relatively recently characterized clinical entity and its similar presentation to pancreatic carcinoma or bile duct cholangiocarcinoma, it is important for autoimmune sclerosing pancreatocholangitis to be included in the differential diagnosis of pancreaticobiliary disease. The management strategy has shown to be modified--from major resection to intraoperative biopsy and to the assay of serum IgG4 level without the necessity of histology confirmation.