[External auditory canal osteoma]

Osteomas are a slow growing benign neoplasm of unknown etiology very rarely involving the temporal bone. They develop in the external auditory canal on squamous sections, in the mastoid, middle and inner ear. By bone composition they are divided into spongious (osteoma spongiosum) and compact osteomas (osteoma eburnum); by growth direction, into outward-growing (exosteoma) and in inward-growing (endosteoma); into unilateral and bilateral; by size, into small and gigantic; by surface structure, into smooth and multilobular; by number, into solitary and multiple; into symmetrical and asymmetrical. The symptoms of intracanalicular osteomas are the result of auditory canal obstruction. Diagnosis is made based on case history, clinical examination, audiological processing and radiography (temporal bone CT scan), and confirmed by histopathological examination of the bone. In terms of differential diagnosis, they must be distinguished from exostoses, bone tissue proliferation and osteoid osteomata. The progress of the disease is prolonged, as they are slow growing, asymptomatic and benign tumours. Therapy is surgical only.

The report presents the case of a 70-year old patient with the osteoma of the right external auditory canal. In our patient, the osteoma arose in the auditory canal, the most frequent localization; it was unilateral, solitary, multilobular and compact. It was discovered accidentally, during otoscopic examination. The clinical diagnosis was confirmed by CT scan of the temporal bone. We applied surgical therapy by retroauricular approach. The removed bone change was about 12 mm high, 13-14 mm deep and about 8 mm wide. Histopathological findings confirmed osteoma.

Due to their slow growth, the rate of auditory canal osteomas develop asymptomatically for a long time without the characteristic clinical features. In most cases, they are discovered accidentally during otoscopic or radiographic examination. The method of choice in diagnosis is temporal bone CT scan. Therapy is surgical.