American Board of Internal Medicine (ABIM) Certification Practice Exam

What indicates a patient has type I autoimmune pancreatitis?

1. Increased serum amylase levels

2. Focal pancreatic enlargement

3. Normal pancreatic duct

4. Inflammation of the gallbladder

The correct answer is: Focal pancreatic enlargement

Type I autoimmune pancreatitis, also known as IgG4-related autoimmune pancreatitis, is characterized by specific imaging findings that reflect the disease process. One of the hallmark features of this condition is focal pancreatic enlargement. This occurs as a result of the autoimmune inflammatory process affecting the pancreas, leading to an increase in the size of the organ in a localized manner. The enlargement is typically not accompanied by the diffusely enlarged pancreatic duct seen in other types of pancreatitis. It is essential to note that the inflammation and fibrosis associated with this type of pancreatitis are often limited to certain areas of the pancreas, giving rise to the distinct focal enlargement. Other indicators of type I autoimmune pancreatitis, like increased serum amylase levels, are not specific to this condition. In fact, patients may have normal or slightly elevated enzyme levels primarily related to duct obstruction rather than widespread inflammation. The normal pancreatic duct finding in this condition also differentiates it from other pancreatic disorders where ductal abnormalities are more common. Inflammation of the gallbladder, while it may occur with pancreatitis in general, is not a direct indicator of type I autoimmune pancreatitis. Therefore, the indication of focal pancreatic enlargement serves as a critical diagnostic feature, helping to distinguish autoimmune pancreatitis from