Pleomorphic adenoma, also known as benign mixed tumour, is the most common salivary tumour, constituting up to two-thirds of all salivary gland neoplasms. It shows a female predilection of 2:1.
Mostly, pleomorphic adenoma is located in the parotid glands (85%), the submandibular glands (8%), and minor salivary glands (6.5%). Among minor salivary gland tumours intraorally, they are frequently encountered on the posterior palate (42.6%), followed by the lip (10%), cheek (5.5%), tongue, and floor of the mouth. Pleomorphic adenoma usually manifests as a slow progressing asymptomatic swelling. They are mostly benign; however, they can undergo malignant transformation with perineural invasion if not surgically removed.
Clinically, pleomorphic adenomas are solitary, firm, round tumours. Radiographs play a major role in differentiating pleomorphic adenoma from other cysts and swellings of inflammatory origin. Ultrasound and FNAC can be useful for diagnosis.
Histologically it is composed of epithelial and myoepithelial cells arranged in various morphological patterns. Pleomorphic adenoma of the major salivary glands has a capsule, although it varies in thickness and completeness, whereas pleomorphic adenoma of the minor salivary glands is usually unencapsulated.
They are best treated by a wide local excision with good safety margins and follow-up for at least 3–4 years.
A case of a 40-year-old female presented with swelling in the posterior palate, diagnosed as pleomorphic adenoma with the help of incisional biopsy, followed by complete enucleation under general anaesthesia, and is under regular follow up.