Transcript thyroidppt - Lansing Radiology Associates

Post operative ultrasound
evaluation of the neck in
Thyroid cancer patients
Stephen D. Chapman, D.O.
Lansing Radiology Associates, P.C.
Well differentiated thyroid
cancer
 Thyroid cancer is the most common
endocrine cancer
 Papillary and follicular types are
classified as well-differentiated thyroid
arising from thyroid follicular cells.
 Account for approximately 80% to 90%
of all thyroid cancers.
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
Lymph node anatomy
 Normal lymph nodes
 Cortex contains tightly
are composed of a
packed lymphocytes and
cortex and a medulla
is hypoechoic.
covered by a fibrous
capsule
 Each lymph node
 Medulla is made of
contains a main
trabeculae and
artery that enters at
medullary cords and
the hilus and
sinuses and is
branches into multiple
echogenic
arterioles.
Lymph node anatomy
 Normal 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
Lymph node anatomy
 Small 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.
Lymph node anatomy
 Multiple characteristics should be
visualized to confirm benignity.
 A sole benign criterion is not sufficient
for an accurate diagnosis.
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.
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.
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 cancer
 The cystic change is caused by necrosis
secondary to tumor invasion.
Figure 1. Normal oval-shaped lymph node
with an echogenic
hilum located in zone III.
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.
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.
Figure 4. Normal lymph node within zone VI. Note
the hypoechoic cortex and echogenic hilum.
Precise anatomic localization with cervical US of WBS-depicted recurrence.
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
Precise anatomic localization with cervical US of WBS-depicted recurrence.
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
Technique
 The patient is positioned supine with the
neck hyperextended.
 Typically, a 10 to12-MHz or higher linear
array transducer is used.
Landmarks and Zones
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Table 1. Anatomical Landmarks for Each Zone of the Neck22–24
Zones Landmarks Nodal Group
IA Midline; anterior to the digastric muscle and superior to the hyoid
bone.
Submental
IB Lateral to zone IA but medial or anterior to the submandibular gland
Submandibular nodes
IIA Anterior or medial to the interior jugular vein but lateral/posterior to
the submandibular gland; superior to the hyoid bone
Upper internal jugular chain; more
superiorly, the parotid nodes
IIB Posterior to the interior jugular vein Upper internal jugular chain; more
superiorly, the parotid nodes
III From the level of the hyoid bone inferiorly to the cricoid arch; lateral
to the common carotid artery
Middle internal jugular chain
IV From the level of the cricoid arch inferiorly to the level of the clavicle;
lateral to the common carotid artery
Lower internal jugular chain
VA Posterior to the sternocleidomastoid muscle, from the base of the
skull to the cricoid arch
Supraclavicular fossa/posterior triangle
(spinal accessory chain and transverse
cervical chain)
VB Posterior to the sternocleidomastoid muscle from the croicoid arch
to the level of the clavicle
Supraclavicular fossa/posterior triangle
(spinal accessory chain and transverse
cervical chain)
VI Anterior/medial to the common carotid arteries from the level of the
hyoid to the manubrium
Anterior cervical nodes, pre- and
paratracheal
VII Anterior/medial to the common carotid arteries, inferior to the
sternal notch
Anterior, upper mediastinal nodes
Supraclavicular Lateral to the common carotid artery; at or inferior to the clavicle
Supraclavicular nodes
Standardized neck imaging classification scheme for reporting
findings in lymph nodes is critical for effective communication with
referring clinicians and surgeons.
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
Figure 6. Chain of abnormal, rounded, hyperechoic
lymph nodes within zone III. Note the lack of an
echogenic hilum
US images of clustered malignant lymph nodes at (a) conventional and (b)
compound imaging. Microcalcifications in smaller lymph node (white
arrows) and cystic degeneration of larger node (black arrows) are specific
findings of DTC nodal metastases.
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
US images of clustered malignant lymph nodes at (a) conventional and (b)
compound imaging. Note decrease in low-level echoes in the cystic node
and increased conspicuity of microcalcifications when compound
imaging is used.
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
US image of 6-mm malignant left level IV lymph node.
Round and echogenic
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
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.
Malignant round echogenic lymph node
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
US features of nodal recurrence.
Microcalcifications in PTC of right lobe and adjacent right level IV lymph
node (arrows).
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
US features of nodal recurrence. Cystic degeneration. Thick septations and
nodular solid components are typical of DTC recurrence.
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
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.
Figure 9. Multiple enlarged cystic lymph nodes
extending from zone III to zone IV. Pathology
confirmed recurrent papillary thyroid cancer.
Figure 10. Another example of an enlarged cystic
lymph node within zone IV. Also note the multiple
microcalcifications.
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.
Figure 5. Normal hilar flow within a cervical lymph
node.
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.
Color Doppler US image of malignant lymph node demonstrates peripheral
vascularity (arrows), in contrast to hilar vascularity typical of reactive lymph
nodes.
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
Well differentiated thyroid
cancer
 Zone VI masses can include
postoperative scarring, muscle,
necrosing fat, suture granulomas,
parathyroid glands, lymph nodes,
remnant tissue, and metastasis
(a) Transverse gadolinium-enhanced T1-weighted MR image shows
enhancement of round right-sided level VI (arrow) and level IV lymph nodes
(arrowheads), typical of recurrence.
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
Johnson N A , Tublin M E Radiology 2008;249:429-444
©2008 by Radiological Society of North America
Figure 12. Hypoechoic oval mass within zone VI. The
differential diagnosis includes recurrent disease,
parathyroid, or abnormal lymph node.
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.
Figure 14. Small, hypoechoic area within zone VI.
The differential diagnosis includes recurrent
disease, parathyroid, abnormal lymph node,
granuloma, or scarring.
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