Primary Ear and Temporal Bone Meningiomas: A Clinicopathologic Study of 36 Cases with a Review of the Literature

Abstract

"Primary" ear and temporal bone meningiomas are tumors that are frequently misdiagnosed and unrecognized, resulting in inappropriate clinical management. To date, a large clinicopathologic study of meningiomas in this anatomic site has not been reported. Thirty-six cases of ear and temporal bone meningiomas diagnosed between 1970 and 1996 were retrieved from our files. Histologic features were reviewed, immunohistochemical analysis was performed (n ‫؍‬ 19), and patient follow-up was obtained (n ‫؍‬ 35). The patients included 24 females and 12 males, aged 10 -80 years (mean, 49.6 years), with female patients presenting at an older age (mean, 52.0 years) than male patients (mean, 44.8 years). Patients presented clinically with hearing changes (n ‫؍‬ 20), otitis (n ‫؍‬ 7), pain (n ‫؍‬ 5), and/or dizziness/vertigo (n ‫؍‬ 3). Symptoms were present for an average of 24.6 months. The tumors affected the middle ear (n ‫؍‬ 25), external auditory canal (n ‫؍‬ 4), or a combination of temporal bone and middle ear (n ‫؍‬ 7). The tumors ranged in size from 0.5 to 4.5 cm in greatest dimension (mean, 1.2 cm). Radiographic studies demonstrated a central nervous system connection in 2 patients. Histologically, the tumors demonstrated features similar to those of intracranial meningiomas, including meningothelial (n ‫؍‬ 33), psammomatous (n ‫؍‬ 2), and atypical (n ‫؍‬ 1). An associated cholesteatoma was identified in 9 cases. Immunohistochemical studies confirmed the diagnosis of meningioma with positive reactions for epithelial membrane antigen (79%) and vimentin (100%). The differential diagnosis includes paraganglioma, schwannoma, carcinoma, melanoma, and middle ear adenoma. Surgical excision was used in all patients. Ten patients developed a recurrence from 5 months to 2 years later. Five patients died with recurrent disease (mean, 3.5 years), and the remaining 30 patients were alive (n ‫؍‬ 25, mean: 19.0 years) or had died (n ‫؍‬ 5, mean: 9.5 years) of unrelated causes without evidence of disease. We conclude that extracranial ear and temporal bone meningiomas are rare tumors histologically similar to their intracranial counterparts. They behave as slow-growing neoplasms with a good overall prognosis (raw 5-y survival, 83%). Extent of surgical excision is probably the most important factor in determining outlook because recurrences develop in 28% of cases.

Middle ear meningioma associated with coclear implant: special attention

“…Embryologically, ectopic meningiomas are postulated to arise from either ''punched off'' embryonal arachnoid cells outside the skull and vertebra that lie along the line of fusion of the primitive nerve or bone sheaths, or it may arise as a result of differential maturation of pluripotent mesenchymal cells (2,7). The first theory is more widely accepted.…”

“…Only an estimated 2% of meningiomas occur extracranially (1); middle ear or temporal bone involvement of meningioma is extremely rare. Thompson et al (2) reported 36 cases of ear and temporal bone meningiomas diagnosed between 1970 and 1996. Many cases of middle ear meningioma were not isolated middle ear meningiomas, but had primary intracranial lesions with involvement of the middle ear.…”

“…The presumed mechanism of extracranial meningioma formation is migration of meningothelial cells through potential routes such as the tegmen tympani, posterior fossa plate, and jugular foramen (2).…”

Temporal bone meningioma involving the middle ear: A case report

“…Depending on the location of the tumor, patients can present with a variety of neurological symptoms, including headaches, speech problems, visual disturbances, cognitive deficits, motor deficits and epilepsy (4). In cases of temporal bone meningioma, otalgia is the most common feature, although hearing loss (conductive, mixed or sensorineural) (14), facial palsy and tinnitus are also common (15). A lower proportion of patients present with other cranial nerve palsies or vestibular symptoms (16).…”

Primary meningioma of the middle ear: case report

“…8 An MRI with gadolinium enhancement is superior to plain X-ray or CT scan for differentiating peripheral extension of an intracranial meningioma from the less common primary extracranial meningioma (as encountered in our patient). 3,8 The differential diagnosis of a middle-ear mass includes schwannoma, glomus tumour, metastatic tumour and ceruminous gland tumour. Differentiation of middle-ear meningioma from facial nerve schwannoma is clinically difficult, due to these tumours' similar clinical presentations.…”