Abstract
Granular cell tumors occur at a wide variety of sites, but rarely in the larynx. A case of laryngeal granular cell tumor on the arytenoid is reported.
A 44-year-old man was referred to our hospital after a laryngeal mass was detected at another hospital. Clinical observation using laryngofiberscopy demonstrated a white mass 5 mm in diameter localized on the left arytenoid of the larynx. Biopsy obtained during laryngofiberscopy confirmed the diagnosis of granular cell tumor, and extirpation of the tumor by laryngomicrosurgery with a CO2 Laser was performed. Upon histological examination, the tumor was found to be covered by squamous epithelial cells that formed a pseudo-epitheliomatous hyperplasia.
The tumor cells were poorly defined, round to oval cells with an eosinophilic fine granular cytoplasm and small condensed nuclei. The tumor cells were positive for PAS stain and were immunohistochemically positive for S-100 protein. In Japan, only slightly more than 10 patients with granular cell tumor of the larynx have been reported.
Almost all granular cell tumors are benign tumors, although there have been some malignant examples with poor prognosis. Since it is frequently difficult to distinguish malignant from benign tumors histopathologically, a tumor diagnosed as granular cell tumor should always be totally excised.
