Autoimmune pancreatitis: A series of 10 cases

Autoimmune pancreatitis (AIP) is an uncommon form of chronic pancreatitis—representing 5–10 % of cases—classified into two subtypes: type 1, associated with IgG4-related disease and systemic involvement, and type 2, limited to the pancreas. It is characterized by lymphoplasmacytic fibroinflammatory changes that may closely mimic pancreatic carcinoma on clinical and imaging grounds. Early recognition of its characteristic features is therefore essential to avoid unnecessary surgical resection. In this retrospective case series, we describe ten patients, mostly men, diagnosed using contrast-enhanced CT or MRI, serum IgG4 measurement, and, in two cases, pancreatic biopsy. Imaging revealed typical diffuse “sausage-shaped” enlargement with delayed enhancement in most patients and a focal enlargement in three patients. All nine patients with type 1 AIP demonstrated elevated IgG4 levels, while the type 2 case showed normal serum values but histological confirmation of Lymphocytes and neutrophils (GELs). Initiation of corticosteroid therapy led to rapid symptomatic relief, radiologic resolution of pancreatic abnormalities, and normalization of laboratory markers in all patients. These findings underscore the value of the diagnostic approach—combining imaging patterns, serology, and selective histopathology—to distinguish AIP from malignancy, guide prompt steroid treatment, and prevent invasive procedures.