Fibrous dysplasia of temporal bone with stenosis of external auditory canal and secondary cholesteatoma

Abstract

The authors give historical reference to the first documentary descriptions of the clinical, radiological, microscopic images of altered bones characteristic of such a rare disease as fibrous dysplasia (FD). FD is caused by a congenital mutation of the GNAS1 gene, which leads to the formation of a fibrous disorganized bone matrix with primitive bone tissue that is not able to mature into lamellar bones. Monossal, polyossal forms of FD are distinguished, as well as multiple bone damage with pigmentation and endocrine abnormalities. In FD, skull bones are usually affected (in order of decreasing frequency): frontal, sphenoid, ethmoid, parietal, temporal and occipital bones. An enlargement in the size of the temporal bone leads to the development of stenosis of the external auditory canal, which is clinically manifested by bleeding from the ear, conductive hearing loss, as well as the development of cholesteratoma. A clinical case of a patient with bilateral localization of temporal bone FD and unilateral clinical manifestation on the left (stenosis of the external auditory canal and secondary cholesteatoma) is presented. At the age of 18, the patient was operated on for the exostosis of the auditory canal in the ENT department of the city hospital, which did not prevent further progression of the disease. After 10 years, the subtotal stenosis of the left auditory canal again developed, which was the reason for the re-operation. The patient underwent surgical treatment followed by dynamic observation and computed tomography of temporal bones for 10 years.