myelomeningocele

noun

my·​e·​lo·​me·​nin·​go·​cele ˌmī-ə-lō-mə-ˈniŋ-gə-ˌsēl, -mə-ˈnin-jə- 

: spina bifida in which neural tissue of the spinal cord and the investing meninges protrude from the spinal column forming a sac under the skin