Assistant Professor of Radiology Shahid Beheshti University of Medical Sciences, Tehran, IRAN
Papillary thyroid carcinoma has a high tendency for metastasis to cervical lymph nodes, but the significance of anatomic compartment of lymph nodes metastasis in PTC remains controversial. The ATA risk stratification system guidelines for management of differentiated thyroid cancer considers size and number of metastatic lymph nodes regardless of anatomic compartment. On the other hand according to eight edition of TNM staging, central and lateral lymph nodes metastasis are classified as N1a and N1b, in which N1b represents more advanced disease.
Recent studies revealed that there is no difference in prognosis of patients with isolated central or lateral nodal metastasis, however better survival belongs to these patients in comparison with concomitant central and lateral neck metastasis. Furthermore skip metastases in lateral lymph nodes without involvement of central nodes are more common in patients with upper pole tumors and PTMC. Patients with skip metastasis are treated more aggressively than ones with central metastasis but regarding new studies burden of lymphatic spread rather than anatomic compartment involvement is more useful in treatment planning.