The unique simultaneous occurrence of a squamous cell carcinoma and a granular cell tumor of the tongue at the same site: a histological and immunohistochemical study.

We report a case of a 47-year-old man with a granular cell tumor (GCT) of the tongue colocalized with a squamous cell carcinoma. To our knowledge, this is the first case to be reported in the literature with such an association. Furthermore, we performed an immunohistochemical analysis with p63 to distinguish pseudoepitheliomatous hyperplasia from invasive squamous cell carcinoma. Clinicians and pathologists must be made aware of this potential diagnostic pitfall so that the workup of a tongue lesion does not end prematurely with a benign diagnosis of granular cell tumor with overlying pseudoepitheliomatous hyperplasia.