IgG4-related sclerosing cholangitis mimicking cholangiocellular carcinoma in a patient with obstructive jaundice

IgG4-related disease has gained increased attention worldwide. While the initial focus was on autoimmune pancreatitis which was first described in Asian populations and turned out to be of relevance in Western populations too, the scope has recently broadened towards a notion of a multi-systemic disease with very diverse manifestations such as autoimmune pancreatitis, IgG4-related sclerosing cholangitis (IgG4-SC), retroperitoneal fibrosis and tubulointerstitial nephritis. IgG4-SC (also known as IgG4-associated cholangitis, IAC) represents a rare but clinically challenging differential diagnosis in patients with obstructive jaundice and proximal extra- or intrahepatic biliary strictures which can be mistaken for cholangiocellular carcinoma (CCC). We present a very rare case of a 79-year-old male patient with a normal serum IgG4-level and without any evidence for autoimmune pancreatitis who presented with obstructive jaundice and biliary strictures at the hepatic duct bifurcation and who underwent hemihepatectomy for suspected CCC. However, on histological examination of the resection specimen CCC could not be confirmed. It was only after several episodes of obstructive jaundice reoccurred that the diagnosis of IgG4-SC could be established by reexamination of the surgical specimen, which showed a dense IgG4-positive lymphoplasmocytic infiltrate. Appropriate medical treatment with steroids and azathioprine led to complete remission of the disease. IgG4-SC represents a rare but important differential diagnosis in patients with obstructive jaundice since it usually responds well to steroids and early recognition can save patients from unnecessary surgery.

Fig. 1: PTCD showing sclerosing cholangitis with multiple biliary strictures (e.g. arrow, clips after hemihepatectomy in situ)

Fig. 2: Histopathological findings of the extrahepatic bile ducts with concentrical fibrosis and a transmural dense lymphoplasmocytic infiltrate involving peribiliary glands.

Fig. 3: The bile duct epithelium is preserved, while the stroma shows a dense inflammatory infiltrate containing many plasma cells (HE, original magnification 400x), mostly positive for IgG (left insert, original magnification 400x) and IgG4 (right insert, original magnification 400x).

Fig. 4: Significant regression of biliary strictures 6 weeks after initiation of prednisolone treatment

IgG4 - cholangiocellular carcinoma - cholangitis - jaundice