Isolated mass-forming IgG4-related sclerosing cholangitis masquerading as extrahepatic cholangiocarcinoma: A case report

Figure 1 Preoperative imaging. A: Pancreas computed tomography indicates proximal common bile duct (CBD) stricture with wall thickening (arrow head) and marked dilatation of the proximal bile duct and gallbladder; B: Magnetic resonance cholangiopancreaticography also demonstrates short segmental stricture of the proximal CBD (arrow head) with diffuse dilatation of the peripheral bile duct.

Figure 2 Preoperative endoscopic cholangiogram. Endoscopic retrograde cholangiopancreaticography confirms the 1 cm-lengthened segmental stricture at the proximal common bile duct with marked dilatation of the central bile duct.

Figure 3 Preoperative positron emission tomography-computed tomography. A focal hypermetabolic lesion (SUVmax 4.2) around the proximal common bile duct is revealed without distant metastasis.

Figure 4 Histopathological examinations. A: The thickened bile duct wall demonstrates a marked sclerosis with diffuse lymphoplasmacytes and some eosinophils infiltration; B: Obliterative phlebitis is apparent; C: Numerous IgG4+ cells are detected by immunohistochemical staining.

Figure 5 Gross findings of the specimen. The tumor is shown to be located around the cystic duct orifice and is grossly about 2-cm long. Depth of invasion of the tumor seems to reach the pericholedochal adipose tissue. CBD: Common bile duct; GB: Gallbladder; CHD: Common hepatic duct.