Phenotypic plasticity in parotid tumours: insights from a surgical oncologist's perspective.

Phenotypic plasticity refers to the ability of tumour cells to undergo molecular and phenotypic changes in response to microenvironmental stresses, genetic and epigenetic alterations, or treatment-induced selective pressures, thereby promoting tumour progression. This case report discusses a man in his 70s with pleomorphic adenoma of the parotid, where phenotypic plasticity led to the development of pleomorphic liposarcoma in the parotid through transdifferentiation. Sarcomas can arise in the parotid from pre-existing pleomorphic adenomas or de novo, with only eight reported cases of primary parotid liposarcoma. The less studied pathway is the adenoma-carcinoma-sarcoma progression in pleomorphic adenoma of the parotid. This case report and literature review aim to investigate this evolutionary process and its implications for treatment planning and management from a surgical oncologist's perspective.