LEP and metastatic malignant neoplasm in the lymph nodes: There was a trend for preoperative serum leptin levels to be higher in patients with cervical lymph node metastasis—34.25 (1.50–109.60) ng/ml—compared to those without lymph node metastasis—19.25 (4.20–44.80) ng/ml, however did not reach statistical significance (p = 0.480).