The temporal bone osteoma is a single unilateral lesion and is considered to be rare. An osteoma is benign, slow growing tumor containing mature bone. Confusion has arisen clinically between the osteoma and the exostosis. From the clinical standpoint, the two conditions can be considered separately. The osteoma refers to the solitary pedunculated bony growth, attached to tympanosquamous suture superficial to the isthmus. By contrast the exostosis is broad-based elevations of bone, usually multiple and bilaterally symmertrical, located deep to the isthmus, at the upper edges of the tympanic bone.