A case of needle tract seeding with endoscopic findings of progression over time.

An 83-year-old male underwent three transgastric punctures with endoscopic ultrasound-guided fine-needle aspiration for the examination of a pancreatic body tumor. After a diagnosis of resectable pancreatic cancer and undergoing distal pancreatectomy, the patient was administered postoperative adjuvant chemotherapy with oral S-1 for 6 months, and carcinoembryonic antigen and carbohydrate antigen 19-9 levels were bimonthly evaluated. Carbohydrate antigen 19-9 levels continually increased to 4638.1 U/mL at 45 months post-fine-needle aspiration. Endoscopic ultrasound-guided showed a 25 mm low-echoic, irregularly shaped, and heterogeneous tumor with clear margins protruding from the mucosa outside the gastric wall, and biopsy confirmed adenocarcinoma. Since the immunostaining findings of the specimen matched those of the previously resected specimen, needle tract seeding (NTS) due to puncture of the pancreatic cancer was identified as the cause. After a pylorus-preserving gastrectomy at 46 months post-fine-needle aspiration, postoperative chemotherapy initiation, comprising gemcitabine and nab-paclitaxel, was initiated; however, the patient died despite these interventions as he developed multiple peritoneal dissemination. Although rare, the incidence of NTS will increase in the future owing to the expected extended survival in post-pancreatic cancer resection cases. We suggest regular upper gastrointestinal endoscopy and endoscopic ultrasound-guided evaluations for patients who are at risk for NTS can facilitate early detection. Furthermore, it is extremely relevant to share experiences of encountered NTS cases in practice and extend knowledge of its varying endoscopic appearances.