Timothy C. Hain, MD
Last edited: 1/13/2002
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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 (called glomus tympanicum), the jugular foramen (glomus jugulare) or in the skull base (glomus vagale). The graphic below illustrates the glomus tympanicum location. Glomus tumors are diagnosed by a combination of their location and their highly vascular nature.
Tumors may be treated with radiation or surgery. Surgical treatment often requires obliteration of the middle ear producing a conductive hearing loss. In the past, surgical treatment has been somewhat risky with reports of mortality between 22% and 17%. 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). 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 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, 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.
|Glomus tympanicum tumor (red mass in bottom of middle ear)|
Acknowledgements: Graphics courtesy of Northwestern University.