Optimal Puncture Number and Tissue Evaluation Method in Endoscopic Ultrasound-Guided Fine-Needle Biopsy for Patients with Malignant Neoplasm of Pancreas

Background/Objectives: Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) has become the standard for diagnosing solid pancreatic masses (SPMs). However, in the absence of rapid on-site cytopathologic evaluation (ROSE), the optimal number of needle passes remains uncertain. This study aimed to evaluate the diagnostic perfor-mance of EUS-FNB using a gross-eyed evaluation with fanning techique in patients with pancreatic malignancy. Methods: This retrospective single-center study included 106 patients with confirmed pancreatic malignancy who underwent EUS-FNB with at least three needle passes between January 2022 and December 2024. Gross-eyed visual inspection for whitish core tissue was used to assess specimen adequacy. Primary out-comes were diagnostic accuracy. Secondary outcomes included tissue adequacy and diagnostic yield rate. Results: Diagnostic accuracy improved with additional passes: 73.6% for one pass, 83.0% for two, and 88.7% for three. However, the gain beyond two passes was margin-al. Tissue adequacy was high across all passes (≥94.3%), with most samples deemed adequate within two passes. Diagnostic yield similarly improved from 83.0% (one pass) to 93.4% (three passes). No adverse events were reported. Gross-eyed evaluation was feasible in all cases and guided effective sampling. Conclusions: EUS-FNB with 2 puncture numbers and fanning technique achieves high diagnostic performance for pancreatic malignancy without the need for ROSE and MOSE. Two passes appear sufficient for diagnostic adequacy in most cases, supporting a simplified and safe approach that minimizes unnecessary needle passes.