Pleomorphic adenoma

Pleomorphic adenoma is the most frequently-occurring, benign neoplasia of the salivary glands. It mainly affects the parotid gland and the submandibular glands. Clinically it presents as a slowly growing swelling, variable in size between 2 and 5cm in diameter. Histologically, pleomorphic adenoma displays a marked variability in appearance: the neoplasia is composed of an epithelial component, originating in the duct, and a myoepithelial element immersed in a mesenchymal background. The latter has a chondroid appearance, caused by the depositing of material, produced by the myoepithelial cells. The treatment of choice is surgical excision and the prognosis is positive. However, there can be complications, such as the incomplete removal of the lesions, which frequently recur also after many years with the possibility of a malignant transformation.