On thyroid ultrasound, which features are most suspicious for malignancy?

On thyroid ultrasound, which features are most suspicious for malignancy?

• A. Hypoechoic lesion with microcalcifications.
• B. Spongiform pattern with regular margins.
• C. Isoechoic lesion with smooth margins.
• D. Hypoechoic pattern with microcalcifications, irregular margins, and a taller-than-wide shape.

Answer: (D)

The key idea is that malignancy risk on thyroid ultrasound increases when a nodule exhibits multiple suspicious features, especially when it is hypoechoic and shows microcalcifications, irregular margins, and a taller-than-wide shape. Each feature adds concern, but the combination of all three distinct suspicious traits with microcalcifications and irregular borders plus a non-parallel growth pattern makes cancer much more likely. Microcalcifications, in particular, are highly specific for papillary thyroid carcinoma, and a taller-than-wide orientation in the transverse plane suggests invasion beyond the normal thyroid tissue boundaries. A hypoechoic nodule with microcalcifications and irregular margins that is also taller-than-wide thus represents the most concerning pattern for malignancy. In contrast, a spongiform pattern with regular margins or an iso-echoic lesion with smooth margins are more typical of benign nodules.

The key idea is that malignancy risk on thyroid ultrasound increases when a nodule exhibits multiple suspicious features, especially when it is hypoechoic and shows microcalcifications, irregular margins, and a taller-than-wide shape. Each feature adds concern, but the combination of all three distinct suspicious traits with microcalcifications and irregular borders plus a non-parallel growth pattern makes cancer much more likely. Microcalcifications, in particular, are highly specific for papillary thyroid carcinoma, and a taller-than-wide orientation in the transverse plane suggests invasion beyond the normal thyroid tissue boundaries. A hypoechoic nodule with microcalcifications and irregular margins that is also taller-than-wide thus represents the most concerning pattern for malignancy. In contrast, a spongiform pattern with regular margins or an iso-echoic lesion with smooth margins are more typical of benign nodules.