Neuroendocrine neoplasm of the minor papilla diagnosed with endoscopic ultrasonography-guided fine-needle biopsy and curatively resected by endoscopic papillectomy

Minor papillary neoplasms are rare and surgical resection is the most reported treatment.¹ Moreover, reports of endoscopic resection of neoplasm in the minor papilla are scarce.²

A 47-year-old man with an enlarged minor papilla detected on upper gastrointestinal endoscopy was referred to our institution (Fig. 1a). Duodenoscopy revealed a submucosal epithelial lesion in the minor papilla (Fig. 1b), and endoscopic ultrasonography (EUS) showed an 8 mm hypoechoic neoplasm within the submucosal layer without invasion of the muscularis propria or intraductal extension into the pancreatic duct (Fig. 1c,d). Contrast-enhanced EUS showed that the neoplasm was contrast on isoechoic. Based on EUS-guided fine-needle biopsy (EUS-FNB) with a 22G three-prong asymmetry tip needle (Trident; Micro-Tech Endoscopy, Nanjing, China) using the fanning technique, the lesion was diagnosed as a low-grade (G1) neuroendocrine neoplasm (NEN). Computed tomography and magnetic resonance cholangiopancreatography showed no distant metastases or pancreatic divisum (Fig. 1e,f). The patient declined surgery, so endoscopic papillectomy (EP) was performed. The scope was placed in a semi-push position to position the lesion favorably. A snare was placed on the oral side of the lesion, which was then grasped by pushing the snare inward. During grasping, the scope was placed in a pulled position by stretching. The lesion was resected en bloc in endocut mode. Subsequently, pulsatile bleeding was controlled using hemostatic clips. A pancreatic ductal stent was not placed, as the pancreatic divisum was absent (Video S1). The pathological diagnosis was NEN-G1 without invasion of the muscularis propria or lymphovascular invasion, and the neoplasm was completely resected without any complications (Fig. 2). There was no recurrence within 1 year.

EUS-FNB can be used to diagnose NEN of the minor papilla. EP can be effective for NEN of the minor papilla and should be considered when the neoplasm is <10 mm without intrinsic muscle layer invasion or lymph node metastasis.³

Authors declare no conflict of interest for this article.

Approval of the research protocol by an Institutional Reviewer Board: N/A.

Informed Consent: Informed consent was obtained from the patient in this case report.

Registry and the Registration No. of the study/trial: N/A.

Animal Studies: N/A.