basic
essential
ab ovo
aboriginal
basilar
beginning
bottom
bottommost
central
constituent
constitutive
crucial
elemental
elementary
embryonic
foundational
fundamental
generative
genetic
germinal
gut
in embryo
in ovo
lowermost
lowest
material
nethermost
of the essence
original
pregnant
primal
primary
primeval
primitive
primordial
pristine
protogenic
radical
rudimental
rudimentary
seminal
substantial
substantive
underlying
undermost
adrenal
atypical
cervical
cystic
endometrial
epithelial
follicular
glandular
hepatic
high-grade
intraepithelial
limbic
mammary
medullary
neoplastic
ovarian
prostatic
testicular
thalamic
thyroid
urethral