Mastoid osteoma: A rare incidental finding in an orthodontic patient

Long-Term Surgical Results of Cortical Mastoid Bone Osteomas

“…Osteomas usually involve the craniofacial skeleton being the most frequent benign tumor of the skull and facial bones. Typically, they affect the frontal and ethmoid sinuses, and rarely the EAC, eustachian tube, petrous apex, glenoid fossa, styloid process, middle ear, and ossicular chain [ 1 , 7 , 8 , 9 ]. Mastoid osteomas represent 0.1% to 1% of all benign tumors of the cranial bone and the mastoid represents the most frequent localization within temporal bone [ 2 , 9 ].…”

“…The tumor may also dislocate the posterior meatal wall, leading to conductive hearing loss, or can occasionally extend to the internal table of the temporal bone, causing tenderness on pressure [ 5 , 9 ]. Osteomas can rarely be part of a syndrome such as Gardner syndrome, where multiple osteomas are associated with, subcutaneous fibromas and lipomas, desmoid tumors, epidermal cysts, and intestinal polyposis that carries a high risk of malignant transformation [ 5 , 7 ]. According to a review by Domínguez Pérez et al [ 11 ], from 1861 to 2011, a total of 137 cases of mastoid osteomas have been described, to which about an additional 25 cases in the last 10 years should be included.…”

“…As mastoid osteomas are rare lesions, frequently asymptomatic, and with a certain histopathological variability, accurate preoperative radiological evaluation is of utmost importance for differential diagnosis and early identification of potential complications. The imaging technique for the diagnosis of bone lesions of the mastoid process is CT [ 3 , 7 , 16 , 17 , 18 ]. On CT mastoid osteomas appear as well-demarcated outgrowing lesions from the external cortex.…”

“…Cancellous osteomas are usually pedunculated, having an inner hypodense region surrounded by sclerotic bone. They grow slightly more rapidly than compact osteomas [ 3 , 7 , 18 ]. Differential diagnosis of osteoma involves benign and malignant lesions: exostoses, osteoid osteoma, benign osteoblastoma, ossifying fibroma, fibrous dysplasia, chondroma, osteochondroma, calcified meningioma, isolated eosinophilic granuloma, Paget’s disease, giant cell tumor, osteosarcoma, and osteoblastic metastasis.…”

“…Differential diagnosis of osteoma involves benign and malignant lesions: exostoses, osteoid osteoma, benign osteoblastoma, ossifying fibroma, fibrous dysplasia, chondroma, osteochondroma, calcified meningioma, isolated eosinophilic granuloma, Paget’s disease, giant cell tumor, osteosarcoma, and osteoblastic metastasis. Typically, malignant neoplasms show indistinct margins at imaging [ 2 , 7 ].…”