Magnetic resonance imaging features of a benign peripheral nerve sheath tumour with 'ancient' changes in the tongue of a horse.

Summary A 12-year-old Selle Francais mare was presented because of inspiratory stridor, hypersalivation and dysphagia. A mass at the base of the tongue could be visualised by upper airway endoscopy, oral cavity examination and radiographs of the head. The exact localisation, extent of the mass and extent of tissue infiltration could only be defined by magnetic resonance imaging (MRI). This Case Report illustrates the usefulness of MRI to assess the characteristics and extent of such a lesion and describes the appearance of peripheral nerve sheath tumour in the tongue of a horse.