Characteristic ultrasound property - demonstration of capsule both by gray scale and Doppler mode
Follicular carcinoma - Case 3

Oxyphilic adenoma - Case 1

Oxyphilic adenoma - Case 16

As a rule, follicular tumors are surrounded by a capsule. We have two opportunities to demonstrate capsule on ultrasound. Firstly, by evaluating halo sign, a thin hypoechogenic rim running all along the nodule. Secondly, by demonstrating perinodular blood flow on Doppler mode.