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C H A P T E R 2 | Oncologic Components of Lymphadenectomy

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IA IB

IIB

IIA

VI

III

VA

IV

VB

VII

FIGURE 2-8  Levels I to VII of the lateral compartment.

●● Level III (mid-jugular): Located between the hyoid bone and a horizontal plane defined by the inferior border of the cricoid cartilage. The anterior border is the sternohyoid muscle, and the posterior border is the SCM. ●● Level IV (lower jugular): Adjacent to the lower third of the jugular vein and between the inferior border of the cricoid cartilage and the clavicle, with anterior and posterior borders similar to those of level III. ●● Level V (posterior triangle): Posterior to the posterior border of the SCM and anterior to the anterior border of the trapezius muscle. Level V is divided into VA and VB by a plane defined by the inferior border of the cricoid cartilage. VA is inclusive of nodes surrounding the spinal accessory nerve, and VB includes the transverse cervical and supraclavicular nodes. In metastatic PTC, the key levels in the lateral compartment are IIA, III, IV, and VB. These levels should be included routinely in a lateral compartment neck dissec- tion. Level I is rarely involved with metastasis from PTC; however, because it is not uncommon to find enlarged lymph nodes adjacent to the salivary glands after upper respiratory infection or sinusitis, FNA biopsy of suspicious lymph nodes in level I should be performed prior to inclusion in a lateral compartment neck dissection for PTC. Similarly, inclusion of levels IIB and VA in a lateral compartment neck dissection