Magnetic resonance imaging: is a single scan ever enough for the diagnosis of acoustic neuroma?

A patient presented with unilateral, right-sided hearing loss and tinnitus and underwent gadolinium-enhanced magnetic resonance imaging (MRI). A pure tone audiogram showed a right-sided sensorineural hearing loss. The MRI scan was initially negative but when repeated seven years later, following a further deterioration of symptoms, it showed a 2 mm, right-sided acoustic neuroma. This case has great potential significance for the diagnosis of acoustic neuroma, and it may raise medico-legal issues regarding the exclusion of this diagnosis. The case illustrates that a single negative scan may not be adequate if pure tone audiograms show deterioration in hearing loss.