Solitary fibrous tumor of the paranasal sinuses

Abstract

Although solitary fibrous tumors are well-recognized in the pleura, their occurrence in the paranasal sinuses is decidedly uncommon. We have encountered two cases of solitary fibrous tumors in the paranasal sinuses and report the clinicopathological findings including CD34 immunoreactivity. One tumor arose in a 55-year-old Japanese businessman and the other in a 53-year-old man who had been in the hospital for schizophrenia for 20 years. The tumors showed characteristic findings. Immunoperoxidase stains on paraffin sections showed staining of the cells for anti-vimentin, but there was no staining for anti-keratin, anti-S-100 protein, anti-desmin, anti-glial fibrillary acidic protein (GFAP), or anti-actin. Anti-CD34 monoclonal antibodies also reacted with these tumors, as those of the pleura generally do, and were found to be useful in diagnosing these tumors.