Halo Around Thyroid Nodules

Barry Sacks MD

Introduction

A thin halo is a very good sign and indicates a benign lesion. However it has to be smooth and the thickness has to be the same all around the lesion. If the halo is thick otr irregular and particulalrly if there are other concerning criteria then a biopsy should be performed.

Malignant Halo

Irregular Halo Papillary Carcinoma

A large nodule in the thyroid occupies almost the entire right lobe (a). The nodule measures 2.9cms by 1.5cms. The gland is not enlarged and measures 3.5cms (craniocaudad), by 1.8cms (A-P) by 2.4cms (transverse). The nodule is almost isoechoic with normal thyroid but shows internal irregular areas of hypoechogenicity, regions of isoechogenicity, as well as microcalcifications (white arrows (c). There is irregularity of the border at the posterior aspect of the nodule green arrow a). The halo shows irregular borders in this region as well. Internal vascularity is minimal (d). The irregular surface is concerning for a malignant processes. The diagnosis in this patient was papillary carcinoma

Irregular Halo (green arrow)

A large complex mass occupies more than half the right lobe of the thyroid gland is seen by ultrasound. The mass measures 2.6cms in sagittal and in A-P dimension measures 1.7cms(a). In transverse it measure 1.7cms. It is characterized by a mildly hypoechoic matrix with cystic type serpiginous components. (a) The margins are irregular (white arrow, a) There is an incomplete halo which shows regions of irregularity (green arrow) The lesion is extremely vascular both peripherally and centrally (c) A biopsy was performed and showed medullary carcinoma.