A Comprehensive Review of 148 Cases of Major Salivary Gland Tumours: Critical Insights Into Metastatic Patterns, Prognostic Factors, and Treatment Outcomes

Aim To analyse the clinicopathological characteristics of cases of major salivary gland tumours associated with distant metastasis. Materials and Methods A relevant search of English literature was conducted in PubMed, SpringerLink, ScienceDirect, Scopus, and Google Scholar for distant metastasis from major salivary gland tumours. Results This retrospective study included 148 reported cases. Among them, 79 patients were male and 69 were female. The mean age of the patients was 53 ± 14. The parotid gland was the most frequently metastatic salivary gland, and various bones were the most common metastatic sites, followed by the lungs. Adenoid cystic carcinoma was the most common histological tumour type. The time interval between the development of a primary tumour and the diagnosis of the metastatic lesion ranged from 2 to 600 months. In most patients, the secondary lesion was diagnosed in less than 127 months. In 103 cases, the patient was alive at the time of reporting. Conclusion Adenoid cystic carcinoma and metastasising pleomorphic adenoma are highly aggressive major salivary gland tumours characterised by rapid growth and distant metastasis. Although distant metastasis from major salivary gland tumours is not common, it signifies a poor prognosis, with death occurring within months of detection. Therefore, greater attention should be paid to major salivary gland tumours.