Background
This study aimed to explore the morphological, clinical, and molecular aspects of pleomorphic adenoma (PA) and myoepithelial salivary gland neoplasms, investigating their behavior and potential diagnostic markers.
Objective This article further explores and expands upon this spectrum of molecularly labeled subsets showing specific morphologic features.
Method
Tissue samples from 25 cases of PA were examined, and RNA next-generation sequencing (NGS) was performed on paraffin-embedded sections using the Illumina TruSight RNA Pan-cancer panel. Cellular characteristics, clinical attributes, and molecular profiles were assessed to identify unique features and potential diagnostic indicators.
Results
PA, a prevalent benign tumor, exhibited diverse morphologies and posed risks of recurrence and malignant transformation. Notably, specific metaplasias within PA cells hinted at microenvironment changes and potential behavioral variations. Furthermore, plasmacytoid myoepitheliomas, more aggressive than PA, posed challenges in accurate differentiation. In 12 out of 25 cases, the presence of the CTNNB1:PLAG1 fusion gene alongside plasmacytoid cells confirmed the diagnosis of plasmacytoid pleomorphic adenoma.
Advances in knowledge
The identification of specific metaplasias and fusion genes, notably CTNNB1-PLAG1, provided diagnostic insights, potentially influencing improved diagnostics and targeted treatments in the future.