Autoimmune pancreatitis: Multimodality non-invasive imaging diagnosis

Area of Science:

• Gastroenterology
• Radiology
• Immunology

Background:

• Autoimmune pancreatitis (AIP) presents with jaundice, steroid responsiveness, and lymphoplasmacytic infiltrate.
• Type 1 AIP links to IgG4-related disease with elevated IgG4, while Type 2 is pancreas-specific.
• AIP is diagnosed in 2%-6% of patients evaluated for pancreatic cancer.

Purpose of the Study:

• To detail the imaging features of autoimmune pancreatitis (AIP) across various modalities.
• To emphasize the differential diagnosis between AIP and pancreatic ductal adenocarcinoma.
• To highlight the role of imaging in AIP management, including therapy monitoring and recurrence detection.

Main Methods:

• Review of ultrasonography, computed tomography (CT), magnetic resonance (MR), and positron emission tomography/CT (PET/CT) findings in AIP.
• Comparison of imaging characteristics to differentiate AIP from pancreatic cancer.
• Assessment of imaging's utility in monitoring treatment response and disease recurrence.

Main Results:

• AIP exhibits distinct imaging patterns: diffuse "sausage-like" enlargement, focal mass mimicking malignancy, or multifocal involvement.
• Distinguishing AIP from pancreatic ductal adenocarcinoma is critical for treatment planning.
• Imaging aids in assessing treatment effectiveness and identifying disease recurrence.

Conclusions:

• Accurate and early differential diagnosis of AIP using non-invasive imaging is vital.
• Correct diagnosis prevents unnecessary pancreatic surgery for AIP patients.
• Imaging surveillance is essential for managing AIP, guiding therapy, and monitoring outcomes.