thyroid nodule       
noun [ C ]  medical specialized uk/ˈθaɪ.rɔɪd ˌnɒd.juːl/ us/ˈθaɪ.rɔɪd ˌnɑː.djuːl/
 甲状腺结节
a growth that forms on the thyroid gland (= an organ in the neck that is involved in controlling the way the body develops and works)
  Thyroid nodules are very common in children and young adults. 甲状腺结节在青少年中很常见。