Histopathological evaluation of needle tract seeding caused by EUS-fine-needle biopsy based on resected specimens from patients with solid pancreatic masses: An analysis of 73 consecutive cases

Background and Objectives: EUS-guided fine-needle biopsy (EUS-FNB) is considered a safe and useful method for preoperative diagnosis of resectable solid pancreatic masses. However, needle tract seeding (NTS) after EUS-FNB has recently been reported, which may affect long-term outcome. The aim of this study was to evaluate NTS after EUS-FNB. Materials and Methods: We reviewed 73 resected cases that underwent preoperative EUS-FNB for a pancreatic tumor from April 2014 to March 2016 and evaluated the utility and adverse events of EUS-FNB based on consecutively resected pathological specimens. Results: The final diagnoses were pancreatic ductal adenocarcinoma (n = 67), neuroendocrine neoplasm (n = 5), and acinar cell carcinoma (n = 1). The diagnostic accuracy of preoperative EUS-FNB was 98.6%. Clinical adverse events were observed in 4.1% of cases (bleeding, n = 2; acute pancreatitis, n = 1) and abnormal pathological findings in 4.1% (NTS, n = 2; acute focal pancreatitis, n = 1). Conclusions: Although EUS-FNB is useful for preoperative diagnosis of pancreatic tumors, we may need to reconsider the risk of NTS and use of EUS-FNB in patients with a resectable solid pancreatic mass unless the tract itself is planned to be resected.