Forward‐Viewing Endoscopic Ultrasound‐Guided Fine‐Needle Biopsy for a Hypopharyngeal Carcinoma Mimicking a Subepithelial Lesion: A Case Report

Subepithelial lesions (SELs) of the head and neck have a low diagnostic yield with mucosal biopsy and carry a bleeding risk. Among endoscopic ultrasound-tissue acquisition (EUS-TA) techniques, fine-needle biopsy (FNB) provides higher specimen adequacy and diagnostic accuracy than fine-needle aspiration (FNA). A forward-viewing curved linear-array echoendoscope (FV-EUS) is useful for mobile lesions and those in narrow spaces that are difficult to puncture with conventional oblique-viewing EUS (OV-EUS), but FV-EUS-guided EUS-FNB has not been reported for head and neck lesions. We report a 72-year-old man in whom a lesion at the esophageal inlet was not apparent on initial upper gastrointestinal endoscopy performed with a small-caliber endoscope. Stenosis was subsequently noted at the time of endoscopic submucosal dissection for early gastric cancer. Contrast-enhanced computed tomography showed an approximately 20-mm solid mass on the posterior hypopharyngeal wall. Under general anesthesia with laryngoscopic exposure, an elevated subepithelial lesion without mucosal exposure was observed on the posterior pharyngeal wall. Using FV-EUS with a cap device attached to the scope tip, a 22 × 18 mm hypoechoic subepithelial mass was clearly visualized, and consecutive EUS-FNB was performed with a 22-gauge needle. No complications, including bleeding, occurred. Histopathology and immunohistochemistry demonstrated moderately differentiated squamous cell carcinoma, and the patient was referred for treatment as primary hypopharyngeal cancer. This case illustrates the feasibility and safety of FV-EUS-guided FNB for pharyngeal SELs and suggests a wider role for FV-EUS in head and neck disorders.