A challenging case of squamous metaplasia in a pleomorphic adenoma: diagnostic and clinical pitfalls

Squamous metaplasia in a pleomorphic adenoma (PA) has been reported, but rarely has it been documented as being extensive enough to cause significant misdiagnosis. We present a case of a 37-year-old man presenting with a 1.7-cm minor salivary gland PA of the palate. It exhibited extensive squamous metaplasia mimicking a squamous cell carcinoma (SCC) on multiple preoperative biopsies. The final diagnosis was only made after a complete oncological excision with margins and free flap reconstruction. Florid squamous metaplasia in a PA, although rare, should be recognized and distinguished from SCC. Failure to differentiate these entities can lead to patient overtreatment.