Factors affecting the accuracy of endoscopic ultrasound-guided fine needle aspiration for the diagnosis of small (≤20 mm) pancreatic lesions

To explore the diagnostic value of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for small, solid or semi-solid pancreatic lesions (≤20 mm) and the factors affecting its accuracy. Methods: Altogether 92 patients with small, solid or semi-solid pancreatic lesions who underwent EUS-FNA at the Nanjing Drum Tower Hospital from November 2009 to January 2019 were retrospectively analyzed. Univariate and multivariate analyses were used to determine the factors affecting the accuracy of EUS-FNA for detecting these lesions. Results: Among the 92 cases, 56 (60.9%) were diagnosed as having malignant lesions and 36 (39.1%) as benign lesions, respectively. The overall sensitivity, specificity and accuracy of EUS-FNA for the diagnosis of small, solid or semi-solid pancreatic lesions were 71.4%, 100% and 82.6%, respectively. When considering the impact of the presence of a tissue core on the diagnosis, the sensitivity, specificity, and accuracy of EUS-FNA with tissue core compared with those based on cytology alone were 77.3% vs 50.0%; 100% vs 100%; and 86.8% vs 62.5%, respectively. The multivariate analysis showed that larger tumor size (>15-20 mm) (odds ratio [OR] 4.200, 95% confidence interval [CI] 1.21-14.53, P = 0.023) and histologic diagnosis based on tissue core (OR 4.593, 95% CI 1.03-20.47, P = 0.046) were related to a higher accuracy of EUS-FNA. Adverse events were observed in three patients, all were treated conservatively and recovered within 3 days. Conclusions: EUS-FNA is effective and safe for diagnosing small pancreatic lesions. Tumor size and presence of tissue core are related to higher accuracy of the EUS-FNA.