neutropenia vs leukopenia

neutropenia and leukopenia both are nouns.

Word	Noun	Adjective	Verb	Adverb
neutropenia	Yes	No	No	No
leukopenia	Yes	No	No	No

As nouns, leukopenia is a hypernym of neutropenia; that is, leukopenia is a word with a broader meaning than neutropenia:

neutropenia: leukopenia in which the decrease is primarily in number of neutrophils (the chief phagocytic leukocyte)
leukopenia: an abnormal lowering of the white blood cell count

Other hypernyms of neutropenia include leucopenia.

neutropenia (noun)	leukopenia (noun)
leukopenia in which the decrease is primarily in number of neutrophils (the chief phagocytic leukocyte)	an abnormal lowering of the white blood cell count