Granular cell tumor that originated in a posterior ethmoid sinus

Abstract

A granular cell tumor (GCT) is a rare neoplasm. It grows slowly, presumably originates from a Schwann cell, and is typically benign. Histopathologically, GCTs are composed of loosely infiltrating sheets of large, pale, polyhedral cells with abundant granular eosinophilic cytoplasm and a pale, centrally situated nucleus. Immunohistochemically, GCTs express the S-100 protein and neuron-specific enolase. A GCT can occur anywhere in the body. Half of all GCTs occur in the head and neck regions, especially on the tongue, but they are rarely found in the nasal cavity. A GCT usually arises as a solitary tumor and can be confirmed only by a histologic examination. The appropriate treatment is excision of the lesion. Here, we present a rare case of a GCT originating in the right posterior ethmoid sinus in the nasal cavity. A GCT originating in a posterior ethmoid sinus has not been reported thus far. In our case, a simple nasal polyp was found in the left ethmoid sinus of the patient. Thus, we initially misjudged the GCT in the right nasal cavity as a simple nasal polyp.