PMC

The clinical course of the present case. D-bil: direct bilirubin, PSL: prednisolone, T-bil: total bilirubin

Pathological images of pancreatic tissue specimens obtained by EUS-FNA. (a) Hematoxylin and Eosin staining shows the presence of lymphoplasmacytic infiltration (Original magnification, ×400). (b) IgG4-immunohistochemical staining shows abundant IgG4-positive plasma cells (≥20 positive cells/HPF) (Original magnification, ×400).

Images obtained with the re-escalation of the prednisolone dose. (a) CT shows a shrinking pancreas without dilation of the pancreatic duct. (b) MRCP and (c) ERCP show the marked improvement of distal stricture of the common bile duct and multiple sclerotic changes of the intrahepatic bile.

Pathological images of a bone marrow specimen obtained by bone marrow aspiration. (a, b) Hematoxylin and Eosin staining shows erythroid hyperplasia (M/E ratio, 1.0) with no blast or plasma cell proliferation (Original magnification; a ×100, b ×400). (c) IgG4- Immunohistochemical staining shows no IgG4-positive plasma cells (Original magnification, ×400).

Images obtained at 8 months after tapering prednisolone treatment. (a) CT shows a bulky pancreas with a capsule-like rim without dilation of the pancreatic duct, as seen previously. (b) MRCP shows a distal stricture of the common bile duct with dilation of the hilar bile duct. In addition, the intrahepatic bile duct shows multiple strictures. (c) ERCP shows a distal stricture of the common bile duct with dilation of the hilar bile duct. Moreover, the intrahepatic bile duct shows multiple sclerotic changes with mild strictures.

Images obtained before treatment. (a) Computed tomography (CT) shows a bulky pancreas with a capsule-like rim without dilation of the pancreatic duct. (b) Magnetic resonance cholangiopancreatography (MRCP) shows a distal stricture of the common bile duct with dilation of the upstream bile duct. The main pancreatic duct of the pancreatic head is not detected. (c, d) Endoscopic retrograde cholangiopancreatography (ERCP) shows a distal stricture of the common bile duct with dilation of the upstream bile duct and segmental constriction of the main pancreatic duct at the head of the pancreas. The pancreatic duct at the tail side is not dilated.