Simultaneous occurrence of benign and malignant tumours in the ipsilateral parotid gland-retrospective study.

The simultaneous occurrence of benign and malignant tumours in the ipsilateral parotid gland is extremely rare. The cases of five patients with synchronous multiple parotid gland tumours consisting of diverse combinations of benign and malignant histological types are presented here. In addition, all published cases of this entity identified in the PubMed, Embase, and Web of Science databases up to January 2018 were reviewed. It is concluded that clinical vigilance should be raised when multifocal tumours are indicated by imaging examinations, in the presence of unmovable, painful, and rapid growth or symptoms of facial nerve palsy. In such cases, resected specimens should be sectioned meticulously, especially for tiny lesions, during histopathological sampling. Based on the possibility of the co-existence of benign and malignant neoplasms, it is necessary for clinicians to pay attention to this entity in order to have a favourable outcome.