Pleomorphic adenoma compared with cystadenolymphoma of the parotid gland: which is more common?

The aim of this single-institution, observational study was to detect and explain any potential changes in the incidence of pleomorphic adenoma and cystadenolymphoma over a period of 19 years. The records of all patients who were treated for benign parotid tumours between 2000 and 2018 were evaluated and the data analysed to detect any potential changes in the incidence over time. A total of 2988 patients were studied, 1150 of whom had cystadenolymphomas (39%), and 1047 pleomorphic adenomas (35%). The dominance of cystadenolymphomas was first noted during the period 2004-2007 and remained stable throughout the following years (p=0.05). The predominant incidence of cystadenolymphomas has increased over time and is not expected to change in the next decades.