The Neck: Thyroid Gland
US: Diffusely enlarged hypoechoic gland with increased vascularity. If multinodular, goiter is enlarged and asymmetrical with several focal nodules of mixed echogenicity.
Correlate with antibody results and NM.
US: unilateral, more common on left.
Due to hypertrophy of single lobe or dysfunction.
US: Findings depend on stage, usually diffuse or focal hypoechogenicity and enlargement of both lobes. Doppler shows no increased vascularity.
Clinical signs of thyrotoxicosis in 50%.
Cyst (usually colloid)
US: hypo-/anechoic mass. If any solid component, requires work-up for thyroid malignancy.
MRI: may appear bright on T1 due to hemorrhage, colloid, or high protein.
Uncommon in young children. True thyroid cysts are rare.
US: hypoechoic or anechoic mass, ± internal echoes if infected.
CT: rim-enhancing mass with central low density.
Rare. Suggests congenital pyriform sinus fistula—correlate with barium swallow or fistulogram.
US: Either increased or decreased echogenicity. Classically have hypoechoic halo around isoechoic mass.
May be single or multiple.
May be hyper- or nonfunctioning.
US: Primary imaging modality showing either solid or cystic mass usually hypoechoic but may have hyperechoic calcification. Cervical lymphadenopathy seen in 90%.
Rare. Ninety percent are papillary; three-quarters of cases occur in females.
Neck and chest CECT and bone scan are required for staging.