Case Report: Painless obstructive jaundice caused by IgG4 autoimmune pancreatitis; the role of endoscopic ultrasound in diagnosis

We report the case of a 60-year-old woman, presenting with painless obstructive jaundice of unknown etiology, who was finally found to suffer from type I autoimmune pancreatitis (AIP). This case emphasizes AIP as a rare cause in the differential diagnosis of obstructive jaundice and the role of endoscopic ultrasound (EUS) in final diagnosis, which is difficult to establish. According to diagnostic criteria, we combined the results from serologic, imaging and histological features (specifically lgG4 levels, computed tomography, magnetic resonance imaging/magnetic resonance cholangiopancreatography and EUS) with cytological results, leading to a final diagnosis. Our patient’s response to corticosteroids was impressive, confirming the diagnosis, leading to complete remission of the disease. Whilst diagnosis of AIP is challenging, the application of diagnostic criteria can lead to correct diagnosis. Therapy is corticosteroid based, with very satisfying outcomes.