RET and metastatic malignant neoplasm in the lymph nodes: In a large meta-analysis including 964 sporadic MTCs from 23 studies, the sporadic MTCs with somatic RET mutation were associated with a younger age at diagnosis, a higher proportion of pT3/T4 (OR = 2.31, 95%CI [1.55–3.45], I2 = 0%), with an increased risk of lymph node metastasis (OR = 3.61, 95%CI [2.33–5.60, I2 = 0%) and with a higher propensity for distant metastasis (OR = 2.85, 95%CI [1.64–4.94], I2 = 0%) compared to MTCs with wild-type RET [55].