Osteoid Osteoma Invading the Posterior Labyrinth of the Petrous Bone

Abstract

SUMMARY:We report a painless osteoid osteoma of the inner ear in an elderly woman presenting with hearing loss, tinnitus, and vertigo. CT showed a heterogeneous mass containing calcifications involving the posterior labyrinth, which heterogeneously enhanced on postcontrast MR images. Osteoid osteoma should be included in the differential diagnosis of an osteolytic petrous bone lesion with central calcification and enhancement.ABBREVIATIONS: OO ϭ osteoid osteoma O steoid osteoma is a benign osteoblastic tumor, most frequently diagnosed in young men presenting with characteristic pain at the site of the lesion, increasing at night and relieved by salicylates. On CT, the lesion is characterized by a zone of bony sclerosis surrounding a central radiolucent area. 1 OO usually involves long bones and the vertebral column and extremities and is very uncommon in the skull.2 Temporal bone OO is even rarer, with only 4 cases described in the literature, none of which were located in the inner ear.3-5 We report here the first case of a pathologically proved OO invading the posterior labyrinth and review the relevant literature. Case ReportA 77-year-old healthy woman presented with a several-months' history of right hearing loss, vertigo, and tinnitus. There was no associated pain. Physical examination confirmed hearing loss and an estimated vestibular deficiency of 70% on the right side. CT showed an osteolytic, heterogeneous, rounded, well-demarcated petrous lesion, measuring 11 ϫ 6 mm, with central calcifications (Fig 1A). Although such calcifications have been interpreted as newly produced osteoid trabeculae, remnants of destroyed bone might have been possible as well. The lesion spared the cochlea but invaded the posterior labyrinth and the endolymphatic duct. There was a close relationship with the facial nerve (Fig 1B). No sclerotic bone was seen surrounding the lesion. At MR imaging, the lesion demonstrated intermediate signal intensity on T1 and high signal intensity on T2-weighted images and enhanced intensely and heterogeneously after intravenous gadolinium administration (Fig 2). Technetium Tc99m scintigraphy showed a corresponding increased uptake in the petrous bone. The preoperative diagnosis was hemangioma.A surgical approach through a mastoidectomy revealed a gray lesion. The center of the lesion was soft and hemorrhagic, but its periphery was hard and indistinguishable from the surrounding normal bone. Because of the anatomic contact with the tympanic segment of the facial nerve, the lesion was only partially excised. Definitive pathologic examination revealed a nidus formed by a hypervascular young conjunctival stroma with osteoblasts, multinucleated giant cells, and thin osteoid trabeculae, consistent with osteoid osteoma (Fig 3). The postoperative course was uneventful, with normal facial nerve function. At 6-month follow-up, the vertigo had disappeared but the tinnitus remained unchanged. DiscussionOO is a frequent, benign, primary bone tumor accounting for approximately 10% of all primary bone tumors....

Osteomas of temporal bone: a rare presentation

“…In our case external auditory canal, middle ear as well as the mastoid parts of temporal bone were involved. Invasion of posterior labyrinth of petrous bone has been reported by Dugert et al in the year 2010 5. Involvement of lateral semicircular canal and facial canal has been reported here.…”

Osteoid osteoma of the maxillary sinus

“…3,13,14 BT osteoid osteoma tanısında en uygun yöntemdir. 4,13,15 Lezyonun yerine göre klinik semptomlar değişmektedir. En erken ve dikkat çekici belirtisi kademeli olarak geceleri şiddeti artan ağrıdır.…”

“…Nüks oranı yaklaşık %4-10 arasında değişmektedir. 2,14,15 Bizim hastamızda da küretaj ile yapılan patolojik inceleme ve tedavi yetersiz kalmış olup patolojik tanı olarak dev hücreli granülom gelmiştir. Bizim de bu vakada dikkati çekmek istediğimiz nokta; osteoid osteoma vakalarında mümkün olduğunca enblok rezeksiyon yapılması hem tanıda yanlışlıklara sebebiyet vermemek hem de tedavide faydalar sağlayacak olmasıdır.…”

Temporal bone osteoblastoma involving temporomandibular joint diagnosed as simple disc disorders: A case report

“…Osteoid osteoma is histologically identical to osteoblastoma. They are usually distinguished on the basis of size: osteoid osteoma is typically <1 cm and lesions >2 cm will be considered osteoblastoma (19)(20)(21). Osteoblastoma, on the other hand, can be locally aggressive, whereas osteoid osteoma lacks growth and invasiveness potential (1,19).…”