Fibrous xanthoma of the frontal sinus.

Frontal sinus mucocele was our preoperative diagnosis in a patient who had frontal swelling and downward displacement of the eye. Supporting this were typical roentgenogram changes, a long history of asthma, pansinusitis, and previous multiple-polypectomy surgery. Frontal sinus exploration revealed a locally eroding lesion. It was composed of spindled cells and lipid-laden histiocytes with a pattern of fibrous xanthoma and was treated conservatively. It should not be confused with true malignancies such as fibrous histiocytoma having a similar histopathologic appearance and requiring more aggressive surgical treatment.