Ultrasound In Thyroid Cancer Surveillance Flashcards
How many surgical levels of the neck are they?
6 (I - VI)
Compartment I
Submandibular to hyoid bone
Compartment II
From vascular bundle to deep to the sternocleidomastoid above the hyoid.
Compartment III
From vascular bundle to deep to the sternocleidomastoid between the hyoid and cricoid.
Compartment IV
From vascular bundle to deep to the sternocleidomastoid below the cricoid.
Compartment V
Posterior to sternocleidomastoid
Compartment IV
Central compartment below cricoid cartilage.
Approximately how many lymph nodes in the normal neck?
300
Typically how many nodes can be identified on ultrasound?
6 - 20
Why is it important to identify suspicious lymph nodes in the neck?
It changes surgically management
Does prophylactic lateral neck dissection does not improve recurrence free survival for patients with peroperative US negative for lymph nodes?
No
Does lateral neck dissection alter the outcome for preoperative US positive for lymph nodes?
Yes
For macro-nodular disease
What is the sensitivity of a whole body scan?
60 - 75%
What does BRAF/RAS mutation do to sodium iodine symporter?
Lack of transmembrane sodium iodide symporter expression
Lymph nodes: is size or morphology more important?
Morphology
Lymph nodes: is border definition important?
No
What does the hilum contain?
Fat and vessels
Reactive nodes vary over time without progressive growth.
True or false?
True
Lymph node: benign or malignant?
Absent hilar line.
Malignant
Lymph node: benign or malignant?
Rounded appearance…
Malignant
Lymph node: benign or malignant?
Cystic necrosis…
Malignant
What should the AP/T ratio be in a benign lymph mode?
Charecteristics of Malignant Nodes:
Sensitivity?
Disordered vascularity…
86%
Charecteristics of Malignant Nodes:
Sensitivity?
Macrocalcifications…
45%
Charecteristics of Malignant Nodes:
Sensitivity?
Cystic degeneration…
11%
Charecteristics of Malignant Nodes:
Sensitivity?
Absence of hilar line…
95%
Charecteristics of Malignant Nodes:
Sensitivity?
Hypoechoic echotexture…
39%
Charecteristics of Malignant Nodes:
Specificity?
Disordered vascularity
82%
Characteristics of Malignant Nodes:
Specificity?
Macrocalcifications…
100%
Characteristics of Malignant Nodes:
Specificity?
Cystic degeneration…
100%
Characteristics of Malignant Nodes:
Specificity?
Absence of hilar line…
20%
Characteristics of Malignant Nodes:
Specificity?
Hypoechoic echotexture…
18%
When should you biopsy a lymph node?
When a positive result will change management.
How big should a lymph node be for it to be biopsied?
5 - 8 mm
When is a neck MRI or CT done?
To look for occult nodes (mediastinum, retropharynx, parapharyngeal space, low cervical lymph nodes)
Which are easier to detect - lateral or central lymph nodes?
Lateral
