Comparison of endoscopic ultrasound guided 22-gauge core needle with standard 25-gauge fine-needle aspiration for diagnosing solid pancreatic lesions

BACKGROUND AND OBJECTIVES: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the standard modality for diagnosing pancreatic masses. We compared the diagnostic yield of a new EUS-guided 22-gauge core needle biopsy to a standard 25-gauge FNA in sampling the same pancreatic lesions during the same EUS. PATIENTS AND METHODS: The main outcomes of the study were the sample adequacy of each method to provide a final pathological diagnosis, and the concordance in diagnosis between core and FNA specimens. The secondary outcomes were the sensitivity and specificity of the findings for each needle and the incremental yield of using both needles compared with using each needle alone. RESULTS: A total of 56 patients with 61 solid pancreatic lesions were evaluated. The mean number of passes with FNA was 3.5 (ranges 1-8) and with core biopsy needle was 1.7 (ranges 1-5). The proportions of adequate samples were 50/61 (81.9%) for FNA and 45/61 (73.8%) for core biopsy (P = 0.37). The diagnostic yield was 46/61 (75.4%), 42/61 (68.9%) and 47/61 (77.1%) for FNA, core, and both, respectively. There was a substantial agreement of 87.5% (κ = 0.77; P < 0.001) in the findings of core and FNA specimens. The sensitivity for the diagnosis of malignancy for FNA and core biopsy were 68.1% and 59.6%, respectively (P = no significant [NS]). The specificity was 100% for both methods. The incremental increase in sensitivity and specificity by combining both methods are 1.5% and 0%, respectively. CONCLUSION: There are NS differences in the diagnostic yield between EUS-guided 22-gauge core biopsy and standard 25-gauge FNA for diagnosing pancreatic lesions, but core biopsy required fewer numbers of passes. There was NS incremental diagnostic yield when using both needles during the same procedure.