Supplementary Material for: Local Recurrence Due to Needle Tract Seeding After EUS-FNA for Pancreatic Tail Cancer: A Case Report

A 79-year-old man underwent a right hemicolectomy for transverse colon cancer in February 2019. In April 2020, computed tomography (CT) revealed a 16-mm mass in the pancreatic tail, and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) confirmed pancreatic tail adenocarcinoma (cT3N0M0, Stage IIA). After two cycles of preoperative chemotherapy, laparoscopic distal pancreatectomy was performed. No recurrence was observed until August 2022, when elevated carcinoembryonic antigen (CEA) levels and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) revealed a local recurrence near the stomach. Despite treatment with gemcitabine and nab-paclitaxel, the lesion persisted. Repeat EUS-FNA confirmed adenocarcinoma, suggesting needle tract seeding (NTS) from the initial FNA. Subsequently, partial gastrectomy was performed. This case highlights a rare complication of NTS following EUS-FNA, which was successfully managed with surgical resection.