Osteoma of the lateral semicircular canal

Abstract

Osteomas are benign, slow growing tumors of bone that occur almost exclusively in the craniofacial region. They are uncommon in the temporal bone. Surgical excision is indicated in symptomatic cases. An osteoma arising from the lateral semicircular canal growing into the mastoid cavity is extremely rare and usually discovered on routine radiography. We present a case of osteoma arising from the lateral semicircular canal growing into the mastoid cavity, followed by a discussion of the etiology, presentation, and management of osteomas.

Lateral semicircular canal osteoma presenting as chronic postaural fistula

“…Apart from our report, there is only one other reported case of labyrinthine osteoma in the literature from Israel by Ben-Yaakov A et al in 2006 4. Their patient was also a young woman who had previous ear surgery, which suggests the possibility that it was an acquired osteoma triggered due to trauma or infection similar to our patient.…”

Piezosurgery® for removal of symptomatic ear osteoma

“…The size and location of the osteoma as well as the severity of symptoms determine the treatment [9]. The major surgical challenges of removing obstructive EAC osteoma are related to proximity of the temporomandibular joint, facial nerve injury, inability to visualize the medial EAC landmarks, the thin skin covering the osteoma, and contact with the tympanic membrane [1,2,10].…”

Osteoma Originating from Mastoid Cortex

“…Temporal bone osteomas are rarely seen, slowly growing, benign, mesenchymal, osteoblastic tumors (1,4). Mastoid osteomas were first reported in the literature by Politzer in 1887, and D'Ottavi et al (5) reviewed almost 100 previously reported mastoid osteoma cases and reported two more cases.…”

“…An intrapetrosal extension is not seen in superficial osteomas, and mastoid aeration is normal. Osteomas rarely extend medially to the petrous bone or lateral semicircular canal or ossicles (4). Temporal bone CT is very useful while planning surgical procedures in such cases.…”

“…Other benign lesions including osteoid osteomas, osteoblastomas, ossifying fibromas, fibrous dysplasia, chondromas, osteochondromas, Paget's disease, and giant cell tumors should be kept in mind in the differential diagnosis. Moreover, malignant lesions such as osteosarcomas and osteoblastic metastases should be considered (4,7,8). Rapid growth, pain, irregular borders, heterogeneous structures, and an osteolytic appearance on performing temporal bone CT indicate malignancy.…”