A Case Report of a Solitary Fibrous Tumor Occurring in the Paranasal Sinus

Abstract

Solitary fibrous tumor (SFT) is a relatively rare mesenchymal neoplasm that usually arises in the pleura. Recently, SFT has been reported to occur in various extrapleural sites such as the liver, thyroid, sublingual gland, nasopharynx, and parapharyngeal space without any relation to serosal surfaces. SFT occurring in the nasal cavity and paranasal sinus is extremely rare, with only 3 cases being previously reported in the Japanese literature. We report here a case of SFT occurring in the paranasal sinus of a 46-year-old female. CT scan demonstrated an enhanced solid tumor occupying the left nasal cavity with extension posteriorly to the nasopharynx. MRI showed a hypointense mass on T1-weighted images and a heterogenous isointense mass on T2-weighted images. The tumor showed a prominent and inhomogenous enhancement with gadolinium. The tumor was removed by an endoscopic transnasal approach under general anesthesia. Since the tumor was too large and hard to remove en-block, the lesion was resected in a few fragments. Immunohistochemical study revealed that the tumor cells were positive for CD34, Bcl-2, and vimentin, and the tumor was pathologically diagnosed as SFT.