Polymorphous low-grade adenocarcinoma: a 'new' salivary gland tumour

We describe the clinicopathological features of polymorphic low-grade adenocarcinoma. The hallmarks of cytologic uniformity, remarkable histologic diversity, and favourable prognosis are emphasized. Polymorphous low-grade adenocarcinoma is not listed in the existing WHO classification, but recent reports indicate that it may be the second most common malignant intraoral salivary gland tumour. Both pathologists and ENT surgeons, who are not specialized in salivary gland tumours, may not be familiar with this tumour entity, and polymorphous low-grade adenocarcinoma therefore merits a detailed description.