Spindle cell sarcomas, suggestive of peripheral nerve sheath tumours, arising in the tongues of two cats

CASE SUMMARY: Two domestic shorthair cats, one an 11-year-old female neutered cat and the other a 13-year-old male neutered cat, presented with partly raised, well-demarcated masses at the rostral tip of the tongue. Histological examination and immunohistochemical staining were consistent with sarcomas, and were most suggestive of peripheral nerve sheath tumours. One tumour had histological features consistent with a malignant peripheral nerve sheath tumour (PNST). RELEVANCE AND NOVEL INFORMATION: Feline PNSTs arising on the tongue are rarely described in the published literature, and, to our knowledge, a case of malignant PNST originating at this site has not been described to date. Therefore, this represents a new differential diagnosis for cats presenting with a lingual mass. Regardless of histological malignancy, in cats these tumours have the potential for local recurrence but appear very unlikely to metastasise.