Lymph Node Surgery for Thyroid Cancer

Level

Nodes

Lateral compartment

Submental and submandibular nodes

Deep cervical nodes from the skull base to the level of the hyoid. Further divided by the relationship to the accessory nerve (level 2a being medial and 2b lateral)

III

Deep cervical nodes from the level of the hyoid to the cricoid

Deep cervical nodes from the level of the cricoid to the suprasternal notch

Posterior triangle nodes can be divided by their relationship to a plane drawn through the level of the cricoid cartilage (Va is above and Vb is below the accessory nerve)

Central compartment

Pre- and paratracheal nodes from the level of the hyoid bone above to the sternal notch below and the carotid artery laterally

Mediastinal compartment

VII

Superior mediastinal nodes as far as the superior aspect of the brachiocephalic vein

Table 21.2

Lymph node staging

NX	Regional lymph nodes cannot be assessed
N0	No regional lymph node metastasis
N1	Regional lymph node metastasis
N1a	Metastasis in level VI (pretracheal and paratracheal, including prelaryngeal and Delphian lymph nodes)
N1b	Metastasis in other unilateral, bilateral, or contralateral cervical or upper/superior mediastinal lymph nodes

Used with the permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer Science and Business Media LLC, www.springer.com

Nodal disease is usually ipsilateral but may be bilateral (30 %).

Lymph node metastases to the regional lymph nodes are relatively common in PTC and occur early on; the incidence of palpable neck disease is between 15 and 40 % (40–90 % have occult disease).

Metastases from follicular carcinoma are less common (<20 %).

Recurrent disease in lymph nodes accounts for 60–75 % of all neck recurrences.

Elderly patients and those with bilateral and mediastinal disease have a poorer prognosis.

Lymphatic Drainage of the Thyroid

Lymph node groups at the highest risk of metastases from DTC are in the central compartment (level VI), the lower jugular chain (levels III and VI), and the lower posterior triangle (level Vb) (Fig. 21.1).

Fig. 21.1

Lymph node levels of the neck (Reproduced with permission from Watkinson JC, Gilbert RW, Arnold H, editors. Stell and Maran’s textbook of head and neck surgery and oncology. 5th ed. London: Hodder Arnold; 2012. p. 433, Fig 23.12)