A case of a solitary fibrous tumor in the floor of mouth

Abstract

Solitary fibrous tumors （SFTs） are undifferentiated mesenchymal tumors and their incidence has been increasing in recent years. In the stomatognathic region, SFTs commonly affect the buccal mucosa and the tongue, but there are few reports of SFTs occurring in the floor of mouth. We present a case of a SFT in the floor of mouth in a 40-year-old man who was successfully managed through surgery.
In April 2021, a 40-year-old man presented to our department with swelling on the floor of the mouth, and on examination a 20 mm painless mass with a normal surface appearance was found. Magnetic resonance imaging revealed low-intensity signals on T1 weighted imaging, and mixed high- and low-intensity signals on T2 weighted imaging. Sublingual gland extirpation and tumorectomy were performed under general anesthesia.
On histopathologic examination, the tumor displayed abundant collagen fibers, short spindle-shaped tumor cells, and numerous staghorn-like irregular blood vessels. The tumor tissue was observed to be mixed with glandular tissue. The tumor was positive for CD34 and STAT6 markers. These findings confirmed the diagnosis of an SFT. One year and four months postoperatively, the patient is doing well with no recurrence at the primary site and no systemic metastasis has been observed.