A case of fibrous dysplasia of the temporal bone

Abstract

Fibrous dysplasia involving the temporal bone is unusual. The most common initial findings are stenosis of the external auditory canal and conductive hearing loss. We report a case of monostotic fibrous dysplasia of the temporal bone. The patient was a 66-year-old man, who complained of hearing loss in the left ear and swelling of the left temporal region of the head. The left external auditory canal was stenotic, so an audiogram demonstrated a conductive hearing loss. A plain skull roentgenogram and CT scan showed swelling of the left temporal bone with ground-glass appearance and bony stenosis of the left external auditory canal. Canalplasty and cranioplasty were performed by a doctor of otorhinolaryngology and plastic surgery. The left external auditory canal was opened and hearing loss was improved, and this condition was maintained for one year after the operation at our hospital. Fibrous dysplasia is one of the benign and chronic proliferations of fibrous tissue and bone. Although it produces tumorous masses, not all authors agree that the process is truly neoplastic. Most cases involve a single bone, but about 20% of patients have polyostotic involvement and often with extraosseous abnormalities. This disease produces widely variable radiographic images. Often, there is a ground-glass appearance with a density similar to that of the surrounding cancellous bone, but lacking a trabecular structure.