On ultrasound, thyroid adenoma is characterized by halo sign or smooth margin of thyroid, hyperechoic nodules, and normal reactive cervical nodes.

• The blood assays may be accompanied by ultrasound imaging of the nodule to determine the position, size, and texture, and to assess whether the nodule may be cystic (fluid filled).
• Ultrasound features showing a significant association with malignancy:^[1]
  • Solid component
  • Hypoechogenicity
  • Marked hypoechogenicity
  • Microlobulated or irregular margins
  • Microcalcifications
  • Taller-than-wide shape

• Risk of malignancy increases with the increase in number of suspicious ultrasound features.^[1]

Ultrasound characteristics of thyroid nodules ▸ Halo sign or a smooth magrin ▸ Normal reactive cervical nodes ▸ Cystic nodule ▸ Spongioform nodules ▸ Hyperechoic masses ▸ Eggshell calcifications ▸ A decrease in size over time Adapted from Arzu Tatlıpınar1 and İlkay Kartal [Updated 2015].The Evaluation of Thyroid Nodules. Journal of Thyroid Disorders & Therapy.2015.[2] Colloid Nodule Isoechoic to hypoechoic May have internal cystic or heterogeneous change May have calcification Multiple echogenic foci (of inspissated colloid) with comet tail artifact Ultrasound Examples of Thyroid Adenoma References ↑ 1.0 1.1 Kwak JY, Han KH, Yoon JH, Moon HJ, Son EJ, Park SH; et al. (2011). “Thyroid imaging reporting and data system for US features of nodules: a step in establishing better stratification of cancer risk”. Radiology. 260 (3): 892–9. doi:10.1148/radiol.11110206. PMID 21771959.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link) ↑ İlkay Kartal, Arzu Tatlıpınar (2014). “The Evaluation of Thyroid Nodules”. Journal of Thyroid Disorders and Therapy. 04 (02). doi:10.4172/2167-7948.1000181. ISSN 2167-7948. ↑ “Wikipedia thyroid ultrasound”.