ectopia
noun [ C or U ] medical specialized uk/ekˈtəʊ.pi.ə/ us/ekˈtoʊ.pi.ə/
（先天性或因受伤而）异位
a situation in which an organ or body part is in the wrong position, either from birth or because of an injury
Thyroid ectopia is a frequent cause of congenital hypothyroidism 甲状腺异位是引起先天性甲状腺功能低下的一个十分常见的原因。