The earliest diagnosis of medullary thyroid carcinoma and lichen amyloidosis was reported in 2002 in an asymptomatic 5-year-old child coming from a family with multiple endocrine neoplasia type 2 that harbored RET-Cys634Trp (TGC->TGG) pathogenic variant [37] (Figure 6). The gene discussed is RET; the disease is medullary thyroid gland carcinoma.