Early pancreatic cancer in IgG4-related pancreatic mass: A case report.

IgG4-related disease can manifest diversely, including autoimmune pancreatitis and IgG4-related cholangiopathy. We are reporting a very unusual cause of pancreatic cancer triggered in a previously unknown IgG4-related disease.

A 75-year-old man was diagnosed with a 43 mm × 33 mm pancreatic head tumor after consulting for abdominal pain and jaundice. A pancreaticoduodenectomy was carried out uneventfully, and the histopathology report showed an early stage of acinar-cell pancreatic cancer. The patient reconsulted on the 30^th postoperative day with fever, jaundice and asthenia. Magnetic resonance cholangiopancreatography evidenced an extense bile duct stricture. A percutaneous biliary drainage proved to be ineffective, even after exchanging it with larger bore drainage. Reviewing the surgical specimen, features compatible with IgG4-related disease were observed. Consequently, empiric treatment with steroids was initiated achieving excellent results.

IgG4-related disease may cause chronic inflammation of the pancreas and can condition pancreatic malignancies.