Ultrasound examination of the anterior cervical lymph nodes constitutes an
important component of thyroid ultrasound. Up to 30% of thyroid cancer patients are
found to have cervical lymph node metastasis on the pre-operative ultrasound
examination, leading to altered surgical management. There are six anterior cervical
lymph node compartments that are examined systematically on ultrasound beginning
with compartments I and VI/VII, followed by compartments II, III and IV and finally
compartment V. Low-suspicion cervical nodes are oval in shape with an intact fatty
hilum and central vascularity. Intermediate suspicion nodes are those with an absent
hilum and round shape defined as a nodal long-axis to short-axis ratio less than 2, or a
short-axis ≥ 8 mm in compartment II nodes and ≥ 5 mm in compartments III and IV
and VI. In addition to these changes, high suspicion nodes display one or more of the
following features: microcalcifications, cystic change, hyperechoic component,
irregular margins, and/or peripheral/chaotic vascularity. Nodal microcalcifications and
cystic changes on ultrasound have the highest specificity for metastatic thyroid cancer
followed by hyperechogenicity, peripheral vascularity and a round shape. Suspicious
cervical nodes should be further evaluated with ultrasound-guided fine needle
aspiration biopsies and measurement of tumour markers in the needle washout.
Keywords: Cervical lymph node, Cystic content, Fatty hilum, Fine needle
aspiration, Long-axis, Metastasis, Microcalcifications, Peripheral vascularity,
Power Doppler, Short-axis, Steinkamp’s ratio, Thyroid cancer, Tracheaoesophageal
groove, Tumour markers, Ultrasound.
