'Metastasizing pleomorphic salivary adenoma' should now be considered a low-grade malignancy with a lethal potential

Abstract

Purpose of review: To review the current knowledge on the clinical entity of metastasizing pleomorphic adenoma.

Recent findings: Using case studies, the literature continues to explore the potential to identify a chromosomal abnormality that might explain the clinical entity, and may constitute a submicroscopic malignant transformation with molecular genetic alterations. Presently there are no agreed histopathological parameters that can identify or confirm a difference in behavior between the 'common' pleomorphic adenoma from the metastasizing pleomorphic adenoma.

Summary: The evidence supports that metastasizing pleomorphic adenoma is most likely to be an unrecognized and as yet unclassified malignant neoplasm and as such must be considered a low-grade, potentially lethal malignant disease when it presents, which may constitute a submicroscopic malignant transformation with molecular genetic alterations. Further research is required to answer the many questions.