Current thinking about the management of recurrent pleomorphic adenoma of the parotid: a structured review

Pleomorphic adenoma is the most common tumour of the parotid gland, and can recur after excision. Recurrent pleomorphic adenoma can be a challenge to treat, and has variable outcomes. The aim of this review was to summarise current thinking in its management, which may be helpful to clinical teams and could improve patients' health-related quality of life. We searched several online databases using the key terms pleomorphic adenoma, recurrent pleomorphic adenoma, parotid gland tumours, parotid surgery, radiotherapy and parotid pleomorphic adenoma, and parotid surgery outcomes. Information collected included sample size, recurrence rate, condition of the facial nerve, type of operation, adjuvant treatments associated with recurrence, and clinical outcome. We screened 2301 papers, of which 49 were eligible. There was no consensus among authors about management. There are few if any randomised studies, and so conclusions in most papers were based on coherent arguments. Pleomorphic adenomas of the parotid tend to recur after long intervals, with a propensity towards multifocal disease, and the risk of recurrence (which depends on the initial surgical technique) is higher when the initial operation was done at a young age, after enucleation, and if the initial margins were invaded. Published conclusions suggest that the accepted management varies from observation in selected cases to total parotidectomy with or without postoperative radiotherapy.