A i.e. (Hyperechogenesity) Hyperechoic structure on Ultrasonaography suggests a benign lesion. Malignancies always have a Hypoechoic or nonhomogeneous hypoechoic structure. Echogenecity of Thyroid nodules - The echogenecity of thyroid nodule refers to its brightness compared to the normal thyroid parenchyma - A nodule is charachterized as hypoechoic, isoechoic,hyperechoic or aneclwic - Hypoechogenecity is associated with thyroid malignancy. 'Malignancies always have a Hypoechoic or nonhomogeneous hypoechoic structure' Differentiation of thyroid nodules according to ec o- enicit Echogenecity of the Nodule Most likely diagnosis Hyperechoic, isoechoic Adenomatous (colloid) noodule Hypoechoic Follicular adenoma Malignoma Metastasis Mixed Large nodules echogenicity (follicular adenomas as well as colloid nodules) with regressive changes Anechoic Cyst Ultrasound features of carcinoma in a Thyroid Nodule Feature Carcinoma/Malign ancy Hypoechoic/ Nonhomogeneous/ Solid Structure Regressive changes Microcalcificat ions Rare Common Peripheral rim Variable Internal vascularity Common(70-100 percent) Lymph nodes Relatively common Note : A hypoechoic lesion may be benign or malignant, however a hyperechoic lesion is most often benign