Audiological findings in glomus tumours.

Glomus tumours of the skull base are rare, but as they present with symptoms of hearing loss and tinnitus they are a clinical entity of which audiologists should be aware. This paper describes the findings of the major series of skull base glomus tumours found in the literature, and notes that the contribution of conductive and sensorineural components varies with tumour classification. The reported incidence of hearing loss and tinnitus in glomus tympanicum and glomus jugulare is reviewed and compared with the Cambridge series, in which two tumours were Fisch type A, four type B, two type C and five type D. In each case a mixed hearing loss was found, though the extent of sensorineural impairment was variable. The length of history of tumours limited to the middle-ear was far shorter (mean 8 months) than for more extensive lesions (type B, mean 64 months; C, 48 months; and D, 23 months). Eleven patients (85%) reported the symptom of hearing loss, and 12 (92.5%) of tinnitus, and some patients had experienced these symptoms for some time without seeking the advice of an otologist. It may be concluded that the presence of subjective pulsatile tinnitus or a retrotympanic mass should be considered an indication for an otological opinion, wherein the use of high resolution imaging techniques and arteriography will be considered in conjunction with detailed audiological assessment. Audiologists should be aware of the possibility of glomus tumour in such cases.