A Case of Solitary Fibrous Tumor Occurring in the Nasal Vestibule

Abstract

Solitary fibrous tumor (SFT) is a benign tumor originating from the mesenchyme. While many cases of SFT arising from the serosa, such as the pleura and peritoneum, have been reported, this tumor is relatively rare in the field of otorhinolaryngology. In this article, we report the case of a SFT arising in the nasal vestibule in a female patient.
The patient was a 61-year-old female in whom a SFT was discovered inside the left nasal cavity. Contrast-enhanced CT imaging revealed a heterogeneously enhancing tumor lesion in the nasal cavity. MRI showed a tumor with a uniformity of internal anatomy measuring 3 cm in diameter. On T2-weighted images, the tumor was visualized as a hyperintensity, showing uniformly strong enhancement with gadolinium. Under general anesthesia, the tumor was removed via a gingival incision. On histopathology, the tumor was partially lined by ciliated epithelium and was composed of spindle cells lacking atypia within a subepithelial fibrous framework. Some vitrifications of vasodilatation were also noted. Immunohistochemistry revealed positive staining of the tumor for CD34 and bcl-2, along with positive staining of the tumor margin for SMA and desmin. Based on the above findings, the tumor was diagnosed as SFT. After the operation, the patient has been under outpatient follow-up, and until now, 12 months since the operation, there has been no evidence of recurrence or transfer of the tumor.
Recurrence or transfer of nose/paranasal sinus SFT has not been reported to date in Japan. Complete removal of the tumor by surgery was successfully accomplished in both the previously reported cases. The first surgical removal was considered to be an important indicator to assure a favorable prognosis.