Differentiating Autoimmune Pancreatitis From Pancreatic Cancer: Current Evidence and Emerging Diagnostic Technologies

Autoimmune pancreatitis (AIP) is a relatively rare chronic fibroinflammatory disorder of the pancreas caused by autoimmune mechanisms. Patients with this condition generally show a clear response to glucocorticoid therapy. Notably, its clinical and imaging features often resemble those of pancreatic cancer (PC), particularly when AIP presents as a focal mass. In such cases, clinicians may confuse the two diseases. Given that AIP and PC differ considerably with respect to their biological behavior and treatment, diagnostic errors can lead to unnecessary surgery or delayed treatment. Consequently, it is essential to accurately distinguish between these conditions. Recent diagnostic advances, including the application of liquid biopsy and artificial intelligence, are now being evaluated as alternative approaches to conventional diagnostic methods, and may contribute to improving the distinction between AIP and PC. In this review, we summarize the current evidence, outline the clinical profile of AIP, and compare AIP with PC with respect to epidemiological, clinical, serological, imaging, and histopathological dimensions. In addition, we discuss the advantages and limitations of these new diagnostic tools. Furthermore, we propose a practical three-stage diagnostic algorithm based on the present guidelines. This stepwise approach may provide a practical method for integrating routine and emerging tests for evaluating patients with suspected AIP or PC.