We report a case of solitary fibrous tumor （SFT） of the tongue. The patient was a 58-year-old man who was referred to our hospital because of a swelling on the left side of the tongue in August 2006. A magnetic resonance imaging examination showed a well-demarcated homogenous lesion in the left side of the tongue, with low signal intensity on T1-weighted images and moderate signal intensity on T2-weighted images. A fibroma was suspected on histopathological examination of a biopsy specimen, and surgical excision was performed under general anesthesia. Histopathologically, the tumor was composed of proliferating spindle cells resembling fibroblasts, interstitial collagenous fibers, and microvasculature. The tumor cells were distributed irregularly and were heterogeneous. Immunohistochemically, the tumor cells showed positive staining for CD34, vimentin, and bcl-2, but negative staining for CK AE1/AE3, SMA, and S100 protein. These findings led to a diagnosis of SFT. No recurrence or metastasis has occurred after a follow-up period of 4 years 8 months.
