| Theme |
Benign to Low-malignant Pancreatobiliary Lesionst |
| Title |
Autoimmune Pancreatitis |
| Author |
Terumi Kamisawa |
Departments of Internal Medicine, Tokyo Metropolitan Komagome Hospital |
| Author |
Kensuke Takuma |
Departments of Internal Medicine, Tokyo Metropolitan Komagome Hospital |
| Author |
Taku Tabata |
Departments of Internal Medicine, Tokyo Metropolitan Komagome Hospital |
| Author |
Yoshihiko Inaba |
Departments of Internal Medicine, Tokyo Metropolitan Komagome Hospital |
| Author |
Naoto Egawa |
Departments of Internal Medicine, Tokyo Metropolitan Komagome Hospital |
| [ Summary ] |
Useful findings to differentiate autoimmune pancreatitis (AIP) from pancreatic cancer are as follows：elevation of serum IgG4 levels, diffuse enlargement of the pancreas, delayed enhancement and a capsule-like rim observed with enhanced CTs or MRIs, a high signal intensity area observed with diffusion-weighted MRIs, extrapancreatic lesions with FDG-PET scans, and long or skipped irregular narrowing of the main pancreatic duct on ERCP. EUS-FNA can be used to deny the existence of cancer but histological diagnosis of AIP is rarely made by employing EUS-FNA. Steroid responsiveness is useful for confirmation of diagnosis of AIP in some cases. Differential diagnosis between IgG4-related sclerosing cholangitis and bile duct cancer is sometimes difficult, especially in bile-cytology negative cases. Elevation of serum IgG4 levels, association with other sclerosing diseases, and extensive thickness of the bile duct wall suggest IgG4-related sclerosing cholangitis rather than bile duct cancer. Steroid responsiveness may be a useful diagnostic indicator for diagnosis of IgG4-related sclerosing cholangitis. |