Glomus Jugulare Tumours

They are rare, slow-growing, very vascular tumours of a group called paragangliomas. They are derived from neural tissue and arise within the jugular foramen of the temporal bone. These occur at such sites as the carotid body, the vagus nerve and the middle ear.

The annual incidence is around 1 in 1.3 million people per year.¹ They tend to present between 40 and 70 years of age with a female preponderance of between 3 and 6:1. Sometimes they run in families as an autosomal dominant with incomplete penetrance.² The gene responsible for hereditary paragangliomas³ is on band 11q23.

The tumours grow slowly and may extend to involve the middle ear. Only about 4% metastasise. Metastases have been found in the lung, lymph nodes, liver, vertebrae, ribs, and spleen. The base of the skull is eroded with extension to the mastoid and occipital bones. Between 2 and 4% of tumours produce catecholamines and noradrenaline producing a clinical picture similar to phaeochromocytoma with hypertension and tachycardia. Tumours may also produce somatostatin, vasoactive intestinal polypeptide (VIP) and calcitonin. Features include headache, perspiration, pallor, and nausea.

• The commonest symptoms are deafness and pulsatile tinnitus. Hearing loss may be conductive or sensori-neural.⁴ With the latter there may be vertigo.
• There may be otorrhoea, haemorrhage, bruit and the presence of a middle ear mass.
• Pain in the ear is uncommon.
• The jugular foramen syndrome is paresis of cranial nerves IX to XI and produces hoarseness and dysphagia. It is pathognomonic for this tumour, but it usually follows a year after the initial symptoms of hearing loss and pulsatile tinnitus.
• Less commonly, these tumours produce facial nerve palsy,⁵ hypoglossal nerve palsy, or Horner's syndrome.
• Intracranial extension can produce headache, hydrocephalus and elevated intracranial pressure.
• Ataxia and brainstem symptoms may also develop.
• Involvement of the dural sinuses mimics sinus thrombosis.

Examination

Otoscopic examination reveals a characteristic, pulsatile, reddish-blue tumour behind the tympanic membrane but the true extent is much greater.

Other tumours that have been reported in association with glomus jugulare tumours are pheochromocytoma, parathyroid adenoma, and thyroid carcinoma.

• Audiometry will show a mixture of sensori-neural and conductive loss, the former more marked as the tumour expands.
• Plain skull x-rays may show evidence of the lesion but the best imaging technique is CT along with MRI with DTPA enhancement.
• Arteriography may be required before resection of large tumours.
• There should be screening for catecholamines.

• Chordoma
• Histiocytosis X
• Meningioma
• Primary or metaststic carcinoma
• Cholesteatoma
• Aneurysm
• Lymphoma

The most commonly used clasifications are Glasscock-Jackson and Fisch.

Surgical resection is the treatment of choice but it may be more complex and better avoided in older and more frail patients, especially if there is significant extension.⁶ It can lead to damage of the cranial nerves.¹ Embolisation and radiotherapy⁷ can be used. As it grows so slowly, in the elderly simply watching and waiting with serial imaging may suffice. Alpha and beta blockers may be required for some weeks before treatment if catecholamine production causes high and labile blood pressure.

The approach may depend on the Fisch stage of the tumour:

Type A can be excised by a transmeatal or perimeatal approach.
Type B need an extended posterior tympanotomy.
Type C need radical resection through a combined transmastoid-infratemporal or transtemporal-infratemporal approach preceded by external carotid artery embolisation. Surgery is a therapeutic success in about 90% of patients.
Large type D need to be treated with a combined ENT and neurosurgical approach. It may be possible to remove the entire tumour. Incomplete resection should be followed by radiation and follow-up MRI and CT scans. Megavoltage radiotherapy gives very good results.⁸

Glomus jugulare tumours tend to grow slowly without metastasis and produce cranial nerve palsies that are more cosmetic than debilitating. The overall mortality rate is 8.7% with worse figures for radiotherapy than surgery but they are higher risk patients.Even 20 years after treatment, the survival rate is 94% and 77% of patients remain symptom free.⁹