Objective To analyze the possible correlation between the location of the primary tumor within the thyroid gland and the patterns of central vs lateral compartment lymph node metastasis.
Design Retrospective analysis of papillary thyroid carcinoma (PTC) treated in an academic university setting from July 1, 2004, through August 31, 2010.
Setting Head and neck oncology clinic.
Patients Those receiving surgical therapy for PTC at the University of Utah.
Main Outcome Measures Tumor characteristics of patients with central vs lateral nodal metastatic disease in PTC.
Results Two hundred one patients with PTC met inclusion criteria. There were 136 females (67.7%), and the mean age was 44.8 years. Histologic subtypes included 68 follicular variants of PTC, 111 conventional variants of PTC, and 22 patients with both follicular and conventional PTC variants. Metastatic nodal disease was confirmed histologically in 81 patients (40.3%): 42 with central nodal disease only (20.9%), 10 with lateral disease only (5.0%), and 29 with both central and lateral nodal disease (14.4%). Positive lateral compartment nodal metastasis correlated with distant metastases (P < .01), extrathyroid extension (P < .05), histologic subtype (conventional PTC greater than follicular variant PTC) (P < .05), and tumor location within the thyroid lobe (P < .01). Tumors involving the superior aspect of the thyroid lobe were more likely to be associated with metastasis to the lateral cervical lymph nodes (P < .01), and 76.9% of patients with lateral cervical lymph node disease had involvement of the superior aspect of the lobe. Thyroid microcarcinomas were not associated with lateral cervical compartments in this study.
Conclusions The intrathyroidal location of PTC predicts the pattern of nodal spread. Therefore, patients with PTC involving the superior aspect of the lobe should undergo specific imaging evaluation of the lateral neck compartments to determine the need for lateral compartment neck dissection.