Fig 1.

The 4 categories of thyroid sonography for the classification of PCTNs. A, Benign features in a 60-year-old woman. A longitudinal sonogram of nodular hyperplasia in the left lobe shows a concentric configuration with a centrally located cystic component, a smooth free margin, an ovoid shape, and isoechogenicity. B, Probably benign in a 50-year-old woman. A transverse sonogram of nodular hyperplasia in the left lobe shows an eccentric configuration with a blunt angle between the solid component and the wall (arrows), a smooth free margin, and isoechogenicity. C, Suspicious for malignancy in a 28-year-old woman. A longitudinal sonogram of a papillary thyroid carcinoma in the left lobe shows an eccentric configuration with an acute angle between the solid component and the wall (arrows), a microlobulation, and isoechogenicity. D, Malignant features in a 45-year-old woman. A longitudinal sonogram of a papillary thyroid carcinoma in the left lobe shows an eccentric configuration with an acute angle (arrows), macrolobulation, microcalcifications, and hypoechogenicity.