Glomus Tumors
Timothy C. Hain, MD
Last edited: 1/13/2002
What are Glomus Tumors?
Glomus tumors are also known as temporal bone paragangliomas. They are vascular tumors derived from chemoreceptor organs derived from the neural crest. They were first described by Rosenwasser in 1945.
Glomus tumors may cause hearing loss or pulsating tinnitus. Glomus tumors characteristically affect hearing because they often are located within or adjacent to the temporal bone. Glomus tumors may also affect other nerves in the face (cranial nerves) producing paralysis of the face, pharynx, vocal cords and tongue.
They can develop in the middle ear (glomus tympanicum), the jugular foramen of the skull (glomus jugulare) or in the skull base (glomus vagale). The graphic below illustrates the glomus tympanicum location.
How are Glomus Tumors Diagnosed?
Glomus tumors are diagnosed by a combination of their location and their highly vascular nature. Patients may present to their doctor with a pulsatile tinnitus, or possibly a conductive hearing loss. The tumor may be seen as a reddish discoloration of the ear drum, or be seen on a CT or MRI scan.
How are Glomus Tumors Treated?
Tumors may be treated with radiation or surgery.
Surgical Treatment
Surgical treatment often requires obliteration of the middle ear, producing a permanent conductive hearing loss. In the past, surgical treatment has been somewhat risky with reports of mortality between 17 and 22%. Recent advances in surgical technique have enabled better results. Surgical control can be obtained in 85% of cases with a mortality rate of 2.7% and a recurrence rate of 5.5% (Jackson et al, 2001). Many serious complications are possible related to the vascular nature of the tumor. These include death, CSF leak, infection, carotid artery erosion, stroke and hematoma (Jackson et al, 2001). Section of cranial nerves in the skull base with resultant cranial nerve palsies are also common. These include cranial nerves IX, X, XI, and XII which control swallowing, taste, shoulder movement, and tongue movement. In some cases, resection of the carotid artery is necessary.
Radiation Treatment
Radiation offers another method of treatment. A major benefit is lower mortality than the earlier reports. Radiation does not kill the tumor but causes perivascular fibrosis. Radiation also often damages the cochlea of the inner ear, causing a radiation induced hearing loss. There are also other risks to radiation treatment including the risk of a radiation-induced malignancy.
Glomus tumors can recur, the majority of which occur within the first 10 post-operative years. The median time to recurrence in Jackson's series was 5.87 years.
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Glomus tympanicum tumor (red mass in bottom of middle ear) |
Research Studies on Glomus Tumors
From a recent search of PUBMED, roughly 1200 articles were published between 1966 and 2001 concerning both glomus tumors. At the American Hearing Research Foundation (AHRF), we are are particularly interested in projects that might lead to improved ability to detect and treat glomus tumors. Click here if you would you would like more information about contributing to the AHRF's efforts.
Acknowledgments
Graphics are courtesy of Northwestern University, Chicago, IL.
References
- Jackson CJ and others. Lateral skull base surgery for glomus tumors: long-term control. Otol Neurotol 22: 377-382, 2001
- Rosenwasser H. Carotid body-like tumor of the middle ear and mastoid bone. Arch Otolarygol 1945: 41: 64-7.
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