Correlation of Primary Tumour Size and Central Compartment Lymph Nodes Metastasis in Well Differentiated Thyroid Malignancies in a Tertiary Care Centre.

Abstract

Central compartment lymph nodes are the first to be involved in thyroid carcinoma and associated with higher chances of recurrence. (1) Recurrence and revision surgery can be associated with a high risk of vocal cord paralysis and hypocalcemia. (2) However, the need for central compartment lymph nodes dissection routinely in all cases of thyroid malignancies is controversial considering the risk to recurrent laryngeal nerve and parathyroids. (3) The aim of the study was to evaluate the incidence of central compartment lymph nodes metastasis in well differentiated thyroid malignancy and their correlation with size of the primary tumour along with incidence of postoperative hypocalcemia and recurrent laryngeal nerve injury after central compartment lymph node dissection. Observational study 30 patients diagnosed as well-differentiated thyroid carcinoma after fine needle aspiration cytology and planned for total thyroidectomy and central compartment lymph node dissection in the Department of ENT at a tertiary care hospital in Mysuru were studied. After surgery, histopathological examination (HPE) of thyroid and lymph node specimen was done. Postoperatively, all patients were evaluated for hypocalcemia and recurrent laryngeal nerve injury. The incidence of central compartment lymph node metastasis after HPE was 66.6%. 80% cases with tumor size ≤ 1cm and 64% cases having tumor size > 1cm showed central compartment lymph node involvement. Overall Incidence of transient Hypocalcaemia was 40%. No case of recurrent laryngeal nerve palsy was observed. In well-differentiated thyroid malignancies we found a high incidence of central compartment lymph node involvement which was even higher with primary tumour of smaller size (≤ 1cm). We did not find any incidence of permanent hypocalcemia and recurrent laryngeal nerve injury. So based on our study we emphasize on elective central compartment lymph node clearance to avoid recurrence.