Ultrasound of thyroid cancer

Abstract

The management of thyroid nodules is multi-disciplinary and involves head and neck surgeons, pathologists and radiologists. Ultrasound is easy to perform, widely available, does not involve ionizing radiation and is readily combined with fine needle aspiration cytology (FNAC). It is therefore an ideal investigation of choice for evaluating thyroid nodules. It evaluates specific features that help in identifying the nature of the nodule and FNAC helps in diagnostic accuracy. In addition, following treatment for thyroid cancer ultrasound provides a safe tool for disease surveillance. This paper discusses the role of ultrasound in the management of patients with thyroid cancer.

Figure 1

Longitudinal grey scale sonogram shows a solid, hypoechoic thyroid nodule (arrows) with ill-defined margins anteriorly. Histology: papillary carcinoma.

Figure 2

Longitudinal grey scale sonogram shows characteristic punctate calcification (arrowheads) within an ill-defined solid hypoechoic thyroid nodule (arrows) which is highly suggestive of papillary carcinoma.

Figure 3

Longitudinal grey scale sonogram shows coarse calcifications (arrows) with dense shadowing within a thyroid nodule suggestive of benign calcification.

Figure 4

Transverse grey scale sonogram shows the presence of comet-tail artifacts (arrowheads) within a predominantly cystic thyroid nodule (arrows). Features are of a benign colloid nodule. Curved arrow identifies the internal jugular vein and asterisk marks the common carotid artery.

Figure 5

Longitudinal grey scale sonogram shows a well-defined heterogeneous thyroid nodule (arrows) with a large cystic component (arrowheads) and septation (open arrows). Features are compatible with a benign hyperplastic nodule.

Figure 6

Transverse grey scale sonogram shows a cystic component (open arrows) within a papillary carcinoma (arrows) of the thyroid. The presence of punctate calcification (arrowheads) identifies its malignant nature.

Figure 7

Transverse grey scale sonogram shows a solid, ill-defined, hypoechoic nodule (arrows) containing punctate calcification (arrowheads) in the right lobe of thyroid gland. Features are typical of papillary carcinoma of thyroid. Asterisk identifies the common carotid artery and curved arrow the trachea.

Figure 8

Transverse grey scale sonogram shows multiple round, solid, slightly hyperechoic cervical lymph nodes (arrows) with punctate calcification (arrowheads) in upper jugular chain. Features are suggestive of metastatic lymph nodes from primary papillary carcinoma of thyroid. Curved arrow identifies the internal jugular vein and asterisk marks the common carotid artery.

Figure 9

Transverse grey scale sonogram shows multiple enlarged hypoechoic cervical lymph nodes (arrows) with internal cystic necrosis (arrowheads) in a patient with metastatic lymphadenopathy from papillary carcinoma of thyroid.

Figure 10

Transverse grey scale sonogram shows a large, solid, hypoechoic mass (arrows) occupying the right lobe of thyroid gland. Note the presence of extra-thyroid spread posteriorly (arrowheads). Histology: anaplastic carcinoma. Curved arrow identifies the internal jugular vein and asterisk marks the common carotid artery.

Figure 11

Transverse grey scale sonogram shows an ill-defined, solid, hypoechoic mass (arrows) occupying the left lobe of the thyroid gland. Multiple echogenic foci (arrowheads) casting dense posterior acoustic shadowing probably related to amyloid deposition and associated calcification. Appearance is that of a medullary carcinoma. Note how it closely resembles a papillary carcinoma. Curved arrow identifies the trachea and asterisk marks the common carotid artery.

Figure 12

Longitudinal grey scale sonogram shows a well-defined hyperechoic nodule (arrows) in the left lobe of thyroid gland suggestive of a follicular lesion.

Figure 13

Longitudinal grey scale sonogram shows an ill-defined heterogeneous thyroid nodule (arrows). The hypoechoic nature of the follicular lesion raises the suspicion of follicular carcinoma which was confirmed on subsequent thyroidectomy.

Figure 14

Longitudinal grey scale sonogram shows the presence of floating hypoechoic thrombus (arrowheads) within the distended internal jugular vein (arrows). Colour/power Doppler will demonstrate vascularity in a tumour thrombus which distinguishes it from a stasis venous thrombus.

Figure 15

Transverse grey scale sonogram in a patient with known breast carcinoma shows a well-defined, solid, homogeneous hypoechoic mass (arrows) occupying the right lobe of thyroid. FNAC confirmed a metastatic carcinoma. The curved arrow identifies the trachea and the asterisk marks the common carotid artery.

Figure 16

Longitudinal grey scale sonogram shows an ill-defined, solid, hypoechoic nodule (arrows) in the thyroid gland. Thin echogenic lines (arrowheads) in the adjacent thyroid glandular parenchyma indicate background Hashimoto’s thyroiditis. Biopsy confirmed non-Hodgkin lymphoma of the thyroid gland.

Figure 17

Transverse grey scale sonogram in a patient 1 year after total thyroidectomy for papillary carcinoma shows a small hypoechoic nodule (arrows) with punctate calcification (arrowhead) in the left thyroid bed. FNAC confirmed local tumour recurrence. The curved arrow identifies the trachea, the open arrow the oesophagus and the asterisk marks the common carotid artery.

Figure 18

Transverse grey scale sonogram shows an enlarged hypoechoic right paratracheal lymph node (arrows) 6-months after thyroidectomy for papillary carcinoma. Surgical excision confirmed regional nodal recurrence. The curved arrow identifies the trachea, the open arrow the internal jugular vein and the asterisk marks the common carotid artery.

Figure 19

Transverse grey scale sonogram shows an ill-defined hypoechoic nodule (arrows) in the right thyroid bed containing coarse echogenic foci (arrowheads). Features are suggestive of a suture granuloma. The asterisk identifies the common carotid artery.