IgG4-Related Disease: A Case Report and Diagnostic Challenges

IgG4 disease, also known as IgG4 autoimmune polyexocrinopathy, is a new entity that includes type 1 autoimmune pancreatitis. It has the capacity to affect various organs such as the central nervous system, salivary glands, thyroid, lungs, pancreas, bile ducts, liver, digestive tract, kidneys and prostate, resulting in symptoms specific to the organ affected. It is a rare disease. It is most common in men over the age of 50. Diagnosis is based on histological features such as the presence of a dense lymphoplasmacytic infiltrate in the affected organ, serum IgG4 elevation in more than 80% of cases, IgG4 positivity on immunohistochemistry, fibrosis of the organ and obliterating venulitis. It is sensitive to corticosteroid therapy, which entails a significant risk of relapse when corticosteroid treatment is stopped, necessitating recourse to immunomodulators. We describe the case of a 53-year-old female patient who was admitted to our institution for an aetiological work-up of chronic epigastric pain resembling pancreatic involvement, revealing IgG4 disease.