AUDIOLOGICAL FINDINGS IN GLOMUS TUMORS

Glomus tumours of the skull base are rare, but as they present with sy mptoms of hearing loss and tinnitus they are a clinical entity of whic h audiologists should be aware. This paper describes the findings of t he major series of skull base glomus tumours found in the literature, and notes that the contribution of conductive and sensorineural compon ents varies with tumour classification. The reported incidence of hear ing loss and tinnitus in glomus tympanicum and glomus jugulare is revi ewed 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 impa irment was variable. The length of history of tumours limited to the m iddle-ear was far shorter (mean 8 months) than for more extensive lesi ons (type B, mean 64 months; C, 48 months; and D, 23 months). Eleven p atients (85%) reported the symptom of hearing loss, and 12 (92.5%) of tinnitus, and some patients had experienced these symptoms for some ti me without seeking the advice of an otologist. It may be concluded tha t the presence of subjective pulsatile tinnitus or a retrotympanic mas s should be considered an indication for an otological opinion, wherei n the use of high resolution imaging techniques and arteriography will be considered in conjunction with detailed audiological assessment. A udiologists should be aware of the possibility of glomus tumour in suc h cases.