There are a few fibrous lesions that should be included in the histologic differential diagnosis of tumors in the oral cavity [1,4] such as solitary fibrous tumor, traumatic fibroma, giant cell fibroma, and benign fibrous histiocytoma [8]. The fibroblasts of traumatic fibroma, giant cell fibroma, and benign fibrous histiocytoma do not react with anti-CD34 antibodies [8]. The gene discussed is CD34; the disease is solitary fibrous tumor.