Transcolonic endoscopic ultrasound-guided fine-needle biopsy to diagnose a pancreatic tail adenocarcinoma in a patient with surgically altered anatomy

Previous studies have demonstrated that endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/B) is an efficient method for diagnosing pancreatic masses in patients with surgically altered anatomy [1], but it is sometimes difficult to visualize the target organs from the reconstructed route [2]. Echoendoscope manipulation challenges have restricted the approaches for EUSFNA/B to the lower gastrointestinal tract, through the sigmoid colon and rectum [3]. Meanwhile, transcolonic EUS-FNA/B using forward-viewing echoendoscope or guidewire-assisted techniques have been reported [4, 5]. Herein, we report a case of pancreatic tail adenocarcinoma diagnosed by transcolonic EUS-FNB from the splenic flexure using an overtube method. A 70-year-old woman who had previously undergone esophagectomy with retrosternal gastric tube reconstruction for esophageal carcinoma presented with abdominal pain. Contrast-enhanced computed tomography revealed a 25-mm hypovascular tumor at the pancreatic tail, which was suggestive of pancreatic cancer (▶Fig. 1). Because of the distance between the gastric tube and the pancreas along the postoperative reconstruction, a puncture through the gastric tube was not possible. Therefore, we attempted transcolonic EUS-FNB in order to obtain a biopsy (▶Video 1). First, we inserted a colonoscope with an overtube (ST-C7; Olympus Co., Tokyo, Japan) (▶Fig. 2) up to the splenic flexure. We then placed the overtube at the sigmoid colon, pulled out the colonoscope, and inserted an echoendoscope (GF-UCT260; Olympus Co.) through the overtube to reach the splenic flexure (▶Fig. 3 a). A hypoechogenic tumor was visualized at the pancreatic tail from the splenic flexure, and the lesion was punctured twice with a 22-gauge Franseen needle (Acquire; Boston Scientific Corp., Natick, Massachusetts, USA) under EUS guidance (▶Fig. 3b). The patient received prophylactic antibiotics and no procedure-related adverse events were observed. Histopathological examination revealed adenocarcinoma (▶Fig. 4) and we diagnosed the patient as having a resectable pancreatic ductal adenocarcinoma. She received two cycles of neoadjuvant chemotherapy with gemcitabine and S-1, before undergoing distal pancreatectomy.