Retrocochlear mass lesion in mid-frequency sudden deafness.
OBJECTIVE
This study retrospectively reviewed all cases of mid-frequency sudden deafness to understand the clinical significance of this hallmark finding.


METHODS
Retrospective study.


METHODS
From 1992 to 2006, a total of 556 patients with sudden deafness were experienced. Based on the audiographic configuration, these patients were classified into: flat-type group, 272 cases; high-frequency group, 146 cases; low-frequency group, 70 cases; mid-frequency group, 30 cases; and unclassified group, 38 cases. All patients underwent a battery of audiovestibular function testing.


RESULTS
Among 556 sudden deafness patients, 17 patients (3%) were proved to have a retrocochlear tumor, including mid-frequency group (10), high-frequency group (4), flat-type group (2), and low-frequency group (1). Thus, the mid-frequency group had significantly higher (33%) association with a retrocochlear tumor than other groups.


CONCLUSIONS
One-third of the patients with mid-frequency sudden deafness harbor a true retrocochlear mass lesion; hence, MR imaging is mandatory in such cases.
Lin
Yi-Tsen
YT
Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
Young
Yi-Ho
YH
D000293:Adolescent; D000328:Adult; D001301:Audiometry, Pure-Tone; D003390:Cranial Nerve Neoplasms / Q000150:complications* / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D003639:Hearing Loss, Sudden / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index; D000160:Vestibulocochlear Nerve Diseases / Q000150:complications* / Q000175:diagnosis