Coexistence of granular cell tumor with squamous cell carcinoma on the tongue: a case report.

Introduction: Granular cell tumors (GCTs) are rare and mostly benign soft tissue tumors. Though they have been reported in all parts of body, they are generally located in the head and neck region, especially on the tongue. Some malign forms exist, but these have been rarely reported. Granular cell tumors have a neural origin and, in immunohistochemical evaluations, they express S-100 and neuron specific enolase (NSE). The treatment of these tumors is bulky surgical excision.

Case Report: In this case, a cauliflower shaped lesion with a 1 cm diameter was excised from the midline tongue of a 65 year old woman. The histopathological evaluation indicated that it was squamous cell carcinoma (SCC) covering GCT. Herein, the coexistence of GCT and SCC we describe on the same region of the tongue, in accordance with literature review, since this is a very rare condition.

Conclusion: Pseudoepitheliomatous hyperplasia may accompany GCTs on the tongue and this condition may mimic well-differentiated SCC. For this reason, with the help of Ki-67 and p63 expression, in addition to immunohistochemical markers, well-differentiated SCC should be differentiated from pseudoepitheliomatous hyperplasia through careful investigation.