Diagnostic value of EUS–guided tissue acquisition in suspected autoimmune pancreatitis: A 15-year single-center retrospective study

Background and Objectives Autoimmune pancreatitis is a distinct type of pancreatitis mediated by autoimmune processes. Imaging studies frequently reveal diffuse or focal pancreatic enlargement, as well as irregular narrowing of the pancreatic duct. The clinical manifestations of this condition often overlap with those of other malignant conditions, such as pancreatic cancer, which can result in a high rate of misdiagnosis. EUS–guided fine-needle aspiration biopsy is a novel approach for the pathological diagnosis of AIP, enabling pancreatic tissue sampling. However, there remains a paucity of research on the efficacy of EUS-guided tissue sampling in the diagnosis of suspected AIP. The objective of this study is to assess the diagnostic value of EUS-guided tissue acquisition (including EUS-FNA and EUS-FNB) in patients with suspected AIP. Method Patients suspected of AIP who underwent EUS–guided tissue acquisition (EUS-TA) at Changhai Hospital between 2010 and 2025. Results This study included 148 patients with suspected AIP. Ultimately, 131 were diagnosed with AIP, 9 with pancreatic malignancy, and 8 with other pancreatic diseases. Among the 131 patients diagnosed with AIP, EUS-TA achieved a success rate of 88.66% for obtaining histopathological evidence in type 1 AIP, 76.47% in type 2 AIP, and 85.5% overall for AIP. The ROC curve indicates that EUS-TA demonstrates good diagnostic value for patients suspected of having AIP (AUC = 0.839, 95% CI: 0.729–0.95). Compared with EUS-FNB, EUS-FNA showed significantly lower sensitivity (78.57% vs. 90.67%, P = 0.029), specificity (75% vs. 88.89%, P = 0.017), negative predictive value (33.33% vs. 53.3%, P = 0.007), and accuracy (78.13% vs. 90.48%, P = 0.034). Conclusion EUS-guided tissue acquisition demonstrates good diagnostic value for patients suspected of AIP, with EUS-FNB showing higher diagnostic value for AIP than EUS-FNA. EUS-FNB is the preferred diagnostic method for patients suspected of AIP.