On ultrasound of a suspicious thyroid nodule, which feature set suggests malignancy?

• A. Irregular borders
• B. Hypoechoic
• C. Central vascularity
• D. All of the above

Answer: (D)

In ultrasound evaluation of a thyroid nodule, certain features raise suspicion for cancer because they reflect invasive growth, higher cellularity, and abnormal blood supply. Irregular borders suggest the lesion is infiltrating surrounding tissue rather than forming a well-contained mass. Hypoechogenicity means the nodule is darker than the normal thyroid parenchyma, a pattern more commonly seen in malignant nodules due to increased cellular density and reduced colloid. Central vascularity on Doppler indicates blood flow within the nodule itself, often from chaotic neovascularization associated with malignant processes, as opposed to benign nodules that may have little flow or only peripheral flow. When these features occur together, the likelihood of malignancy is higher, so all of these findings together point toward a malignant nodule.