Pattern of nodal involvement in papillary thyroid cancer: a challenge of quantitative analysis.

Introduction: Backgrounds of this study were to examine and analyse the relationship among the number of lymph nodes with metastases harvested in central and lateral compartments, the characteristics of tumours and patients, and the recurrences rate.

Methods: A retrospective review of 118 patients treated for a papillary thyroid cancer and underwent to neck dissection, including in all cases both central and lateral compartment, was realised. A quantitative analysis, on this homogeneous cohort of patients, was performed to hypothesize the minimum number of cervical lymph nodes to be necessarily excised in order to obtain an adequate management of these patients.

Results: The mean follow-up time was 75.9 months. Five-year overall survival was 96.6%. The correlation among the metastatic lymph node number of the ipsilateral central compartment, isolated or pooled with those of the ipsilateral lateral compartment, age of patient and tumour size revealed a statistical significance (P=0.01); both parameters, tumour size and age, may be considered as dependent predictor variables.

Conclusion: We suppose, notwithstanding the limited number of patients, that the number of lymph nodes harvested to achieve an optimal cervical dissection may be superior to 8 and 11 in central and lateral compartments, and 6 and 10 in contralateral ones, respectively. Moreover we recommend the bilateral dissection of central nodes compartment in presence of tumour localised in the isthmus.