The Importance of Elastography in the Early Diagnosis of Highly Differentiated Parotid Tumors: a Case-Report.

It is indisputable that high-resolution ultrasound (US) is the diagnostic gold standard for the evaluation of superficial parotid gland diseases. It is a dynamic, quick, simple, easily available, cost-effective, noninvasive procedure, with absence of ionizing radiation examination that can be performed safely and in special categories of patients such as pregnant women and children. It is widely accepted that on US, benign tumors have clear, smooth and well-defined borders, homogeneous hypoechoic parenchyma and a defined distribution of vessels. On the other hand, malignant lesions usually have unclear borders; also, they are inhomogeneous and sometimes can have areas of necrosis, increased hypoechogenicity and diffuse vascularization. However, many times these findings are not decisive due to the overlap that often occurs in parotid tumors. Shear wave elastography (SWE) represents a new imaging technique that provides additional information about tissue elasticity and stiffness in a selected region of interest. Since malignant tissues show greater stiffness than benign ones, sonoelastography is used to assist differential diagnosis between malignant and benign lesions. In many other organs, such as breast, thyroid, prostate and liver, it has been already successfully used for the differential diagnosis between malignant and benign lesions. The present article highlights the role of elastography in the diagnosis of a small malignant tumor in the left parotid gland of a 73-year-old female patient.