Pleomorphic Adenoma
Pronunciation: plee-oh-MOR-fik ad-en-OH-mah
The most common benign tumour of the salivary glands, characterised by a mixture of epithelial and mesenchymal-like elements within a variable stroma.
Full Definition
Pleomorphic adenoma is the most frequently occurring salivary gland neoplasm, arising most often in the parotid gland, followed by the palate and other minor salivary gland sites. Its name reflects its morphological diversity, with tumours containing epithelial cells arranged in ducts and sheets, myoepithelial cells, and a variable stroma that may appear myxoid, chondroid, or hyalinised. Although benign, it carries a risk of malignant transformation into carcinoma ex pleomorphic adenoma, particularly in longstanding or recurrent tumours. Editors should note that 'mixed tumour' is an acceptable historical synonym but is increasingly discouraged in favor of 'pleomorphic adenoma' in contemporary literature.
Usage
Usage note: 'Mixed tumour' is a widely understood historical synonym but should be replaced with 'pleomorphic adenoma' in current clinical and academic documents. Distinguish clearly from 'carcinoma ex pleomorphic adenoma,' which is malignant.
In Context
- "MRI revealed a well-defined mass in the superficial lobe of the left parotid gland, consistent with pleomorphic adenoma." — Radiology report
- "The manuscript used 'mixed tumour' throughout; the editor standardized the terminology to 'pleomorphic adenoma' per current WHO nomenclature." — Editorial revision note