Abstract
INTRODUCTION: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is an essential diagnostic tool for pancreatic tumors, but rare complications such as needle tract seeding (NTS) may cause local recurrence. CASE PRESENTATION: A 79-year-old man with a history of right hemicolectomy for colon cancer presented during follow-up in 2020 with a 16-mm pancreatic tail mass. He was asymptomatic, and laboratory findings including carcinoembryonic antigen and carbohydrate antigen 19-9 were normal. EUS-FNA confirmed adenocarcinoma (cT3N0M0, stage IIA), and after neoadjuvant chemotherapy, laparoscopic distal pancreatectomy was performed. No recurrence was observed until 2022, when elevated tumor markers and fluorodeoxyglucose positron emission tomography/computed tomography revealed a lesion near the stomach. Chemotherapy with gemcitabine and nab-paclitaxel was initiated, but the lesion persisted. Repeat EUS-FNA confirmed adenocarcinoma, suggesting NTS from the initial FNA. Subsequently, partial gastrectomy was performed, and pathology confirmed pancreatic adenocarcinoma. CONCLUSION: This case illustrates the risk of NTS following EUS-FNA for pancreatic tail cancer, particularly when the puncture route is not resected during pancreatectomy. Despite neoadjuvant chemotherapy, NTS occurred, indicating that this risk cannot be fully prevented. Surgical resection achieved disease control, underscoring the importance of vigilant follow-up and timely intervention in managing this rare but clinically significant complication.