Presentation on theme: "Post operative ultrasound evaluation of the neck in Thyroid cancer patients Stephen D. Chapman, D.O. Lansing Radiology Associates, P.C."— Presentation transcript:
1 Post operative ultrasound evaluation of the neck in Thyroid cancer patients Stephen D. Chapman, D.O.Lansing Radiology Associates, P.C.
2 Well differentiated thyroid cancer Thyroid cancer is the most common endocrine cancerPapillary and follicular types are classified as well-differentiated thyroid arising from thyroid follicular cells.Account for approximately 80% to 90% of all thyroid cancers.
3 Well differentiated thyroid cancer Sonography can detect recurrent disease as small as 2 to 3 mm; before they become palpable and visualized with other imaging modalities or before laboratory values become abnormal
4 Lymph node anatomyNormal lymph nodes are composed of a cortex and a medulla covered by a fibrous capsuleEach lymph node contains a main artery that enters at the hilus and branches into multiple arterioles.Cortex contains tightly packed lymphocytes and is hypoechoic.Medulla is made of trabeculae and medullary cords and sinuses and is echogenic
5 Lymph node anatomyNormal cervical lymph nodes are typically oblong, oval, cigar, or kidney bean shaped.Reported size criteria are variable; normal nodes have a short- to long-axis ratio of less than 0.5.The presence of an echogenic hilus is a strong predictor of a benign node
6 Lymph node anatomySmall nodes, less than 5 mm, often appear to be avascular.Flow within the larger submandibular and upper cervical lymph nodes may be increased.Peripheral vascularity should not be seen in normal lymph nodes.
7 Lymph node anatomyMultiple characteristics should be visualized to confirm benignity.A sole benign criterion is not sufficient for an accurate diagnosis.
8 Well differentiated thyroid cancer When recurrent disease is present, the lymph node will lose its ovoid, elliptical shape and become more rounded.Lymph nodes that are increasing in size on serial sonograms should be concerning for metastases.
9 Well differentiated thyroid cancer In addition to a lack of a fatty hilum, malignant lymph nodes typically are hypoechoic when compared with the surrounding tissues. This is the case with medullary thyroid cancer and lymphoma.With recurrent papillary thyroid cancer, however, the lymph node is commonly hyperechoic. This hyperechoic appearance is likely due to the presence of thyroglobulin within the lymph node.Peripheral or mixed (peripheral and hilar) flow has been shown to be highly suggestive of malignancy.
10 Well differentiated thyroid cancer Calcifications are typically small (microcalcifications) and peripherally located.Shadowing from the calcification may or may not be visualized.When the cervical lymph node becomes cystic, it is highly suggestive of recurrent papillary thyroid cancerThe cystic change is caused by necrosis secondary to tumor invasion.
11 Figure 1. Normal oval-shaped lymph node with an echogenic hilum located in zone III.
12 Figure 3. (A, B) Reactive lymph nodes within zone II in two different patients. It is not unusual to see larger lymph nodes near the submandibular gland.
13 Figure 2. Jugular lymph nodes are commonly located in chains Figure 2. Jugular lymph nodes are commonly located in chains. Each lymph node should be evaluated for normal characteristics. These three normal lymph nodes with echogenic hilum are located within zone IV.
14 Figure 4. Normal lymph node within zone VI Figure 4. Normal lymph node within zone VI. Note the hypoechoic cortex and echogenic hilum.
17 TechniqueThe patient is positioned supine with the neck hyperextended.Typically, a 10 to12-MHz or higher linear array transducer is used.
18 Landmarks and ZonesTable 1. Anatomical Landmarks for Each Zone of the Neck22–24Zones Landmarks Nodal GroupIA Midline; anterior to the digastric muscle and superior to the hyoidbone.SubmentalIB Lateral to zone IA but medial or anterior to the submandibular gland Submandibular nodesIIA Anterior or medial to the interior jugular vein but lateral/posterior tothe submandibular gland; superior to the hyoid boneUpper internal jugular chain; moresuperiorly, the parotid nodesIIB Posterior to the interior jugular vein Upper internal jugular chain; moreIII From the level of the hyoid bone inferiorly to the cricoid arch; lateralto the common carotid arteryMiddle internal jugular chainIV From the level of the cricoid arch inferiorly to the level of the clavicle;lateral to the common carotid arteryLower internal jugular chainVA Posterior to the sternocleidomastoid muscle, from the base of theskull to the cricoid archSupraclavicular fossa/posterior triangle(spinal accessory chain and transversecervical chain)VB Posterior to the sternocleidomastoid muscle from the croicoid archto the level of the clavicleVI Anterior/medial to the common carotid arteries from the level of thehyoid to the manubriumAnterior cervical nodes, pre- andparatrachealVII Anterior/medial to the common carotid arteries, inferior to thesternal notchAnterior, upper mediastinal nodesSupraclavicular Lateral to the common carotid artery; at or inferior to the clavicle Supraclavicular nodes
25 US features of nodal recurrence US features of nodal recurrence. Two closely opposed nodal metastases smaller than 1 cm. Note cystic degeneration (arrow) and subtle microcalcifications (arrowhead). Small benign lymph node (*) was also confirmed after focused dissection. Note oblong shape and echogenic fatty hilum.US features of nodal recurrence. (a) Two closely opposed nodal metastases smaller than 1 cm. Note cystic degeneration (arrow) and subtle microcalcifications (arrowhead). Small benign lymph node (*) was also confirmed after focused dissection. Note oblong shape and echogenic fatty hilum. (b) Malignant round echogenic lymph node. (c) Microcalcifications in PTC of right lobe and adjacent right level IV lymph node (arrows). (d) Cystic degeneration of large left level III lymph node (arrow). Thick septations and nodular solid components are typical of DTC recurrence.
29 Figure 8. Multiple examples of abnormal lymph nodes showing microcalcifications. (A) Complex lymph node that is recurrent papillary carcinoma by biopsy. (B) Hypoechoic lymph node with microcalcifications that was biopsy-proven recurrent medullary carcinoma. (C) Hyperechoic lymph node with microcalcifications. This lymph node was recurrent papillary carcinoma.
30 Figure 9. Multiple enlarged cystic lymph nodes extending from zone III to zone IV. Pathology confirmed recurrent papillary thyroid cancer.
31 Figure 10. Another example of an enlarged cystic lymph node within zone IV. Also note the multiple microcalcifications.
32 Figure 11. It is important to correlate sonography findings with the patient’s surgical history. In this case, the focal areas within the sternocleidomastoid muscle are autotransplanted parathyroid glands.
33 Figure 5. Normal hilar flow within a cervical lymph node.
34 Figure 7. (A, B) Abnormal, peripheral flow within an abnormal lymph node in two different patients. Also note the rounded, echogenic appearance, microcalcifications, and lack of an echogenic hilum.
40 Figure 12. Hypoechoic oval mass within zone VI Figure 12. Hypoechoic oval mass within zone VI. The differential diagnosis includes recurrent disease, parathyroid, or abnormal lymph node.
41 Figure 13. Zone VI abnormalities Figure 13. Zone VI abnormalities. (A) Hyperechoic oval mass within zone VI is a biopsy-proven recurrent papillary carcinoma. (B) A more hypoechoic mass deep within zone VI in another patient. This was also recurrent papillary carcinoma.
42 Figure 14. Small, hypoechoic area within zone VI Figure 14. Small, hypoechoic area within zone VI. The differential diagnosis includes recurrent disease, parathyroid, abnormal lymph node, granuloma, or scarring.
43 Well differentiated thyroid cancer US was found to be far more sensitive than WBS for the detection of local recurrence (sensitivity, 70% for US vs 20% for WBS); when thyroglobulin measurement was combined with US, the sensitivity and specificity were 96.2% and 100%, respectively, versus 92.7% and 100% for thyroglobulin measurement combined with WBS