Autoimmune pancreatitis (AIP) type 1 (IgG4-related) is characterized by periductal lymphoplasmacytic infiltrate with IgG4+ plasma cells and storiform fibrosis. It typically responds to which treatment, helping distinguish it from pancreatic carcinoma?

• A Corticosteroid (prednisolone) therapy ✓
• B Proton pump inhibitor therapy
• C Endoscopic retrograde cholangiopancreatography with stenting
• D Pancreaticoduodenectomy (Whipple procedure)

Explanation

A dramatic, often complete response to corticosteroids (prednisolone) within 2–4 weeks is pathognomonic of IgG4-related AIP (type 1) and is used both diagnostically and therapeutically to distinguish it from pancreatic ductal adenocarcinoma, which can present similarly with painless jaundice and pancreatic head mass. Elevated serum IgG4 (>2× upper limit) and diffuse sausage-shaped pancreatic enlargement support the diagnosis. Whipple procedure would be inappropriate if AIP is the correct diagnosis.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.