galactocele vs cyst

galactocele and cyst both are nouns.

Word	Noun	Adjective	Verb	Adverb
galactocele	Yes	No	No	No
cyst	Yes	No	No	No

As nouns, cyst is a hypernym of galactocele; that is, cyst is a word with a broader meaning than galactocele:

galactocele: a cystic tumor containing milk or a milky substance (especially in the mammary glands)
cyst: a closed sac that develops abnormally in some body structure

galactocele (noun)	cyst (noun)
a cystic tumor containing milk or a milky substance (especially in the mammary glands)	a small anatomically normal sac or bladderlike structure (especially one containing fluid)
	a closed sac that develops abnormally in some body structure