MKI67 and metastatic malignant neoplasm in the lymph nodes: Other factors, such as sex (p = 0.580), age (p = 0.345), diameter ≥ 3 cm (p = 0.554), a palpable mass in the neck (p = 0.081), serum iPTH (p = 0.541), serum calcium level (p = 0.079), hypercalcemic crisis (p = 0.177), or a Ki67 index ≥ 5% (p = 0.730), were not found to be related to lymph node metastasis risk.