Fine-needle aspiration biopsy of granular cell tumor of the tongue: a technique for the aspiration of oral lesions.

Granular cell tumor is most commonly located in the tongue. Despite this common location, there are few reports of fine-needle aspiration biopsy (FNAB) of the tongue, likely because this is a sensitive area for most patients, and many cytopathologists do not have experience aspirating oral lesions. We report a case of FNAB of a granular cell tumor of the tongue in a 29-year-old man with an unusual presenting history and without symptoms. The diagnosis was made based on the cytomorphology of the direct smears and immunohistochemistry on cell block material. We will also describe cytologic features of the neoplasm, differential diagnosis, and our technique for obtaining the material, as we feel this can be repeated by experienced cytopathologists.