Hypopharyngeal granular cell tumor treated with endoscopic submucosal dissection

A 55-year-old woman was referred to our hospital after screening esophagogastroduodenoscopy revealed an erythematous area in the larynx. Detailed esophagogastroduodenoscopy at our institution initially suggested inflammatory changes. However, pharyngeal observation using the Valsalva maneuver revealed a 4-mm flat, elevated, whitish lesion in the postcricoid region of the hypopharynx. Although endoscopic differential diagnosis was challenging, lymphoid follicles were initially suspected; however, biopsy revealed inflammatory changes. Follow-up esophagogastroduodenoscopy four months later demonstrated persistent findings, and repeat biopsy established the diagnosis of a granular cell tumor.Endoscopic submucosal dissection was performed under general anesthesia, and en bloc resection was achieved. Histopathological examination confirmed a hypopharyngeal granular cell tumor with negative margins. Immunohistochemical analysis revealed diffuse positivity for S-100 protein. Granular cell tumors originate from Schwann cells and can arise throughout the body, including in the skin, oral cavity, and gastrointestinal tract, with the esophagus being the most common gastrointestinal site. The tongue is the most frequent site of granular cell tumors in the oral cavity, whereas their occurrence in the hypopharynx is extremely rare. We report an endoscopically detected hypopharyngeal granular cell tumor treated with endoscopic submucosal dissection. This tumor should be considered in the differential diagnosis of whitish elevated lesions in the hypopharynx.