benign tumor vs nonmalignant neoplasm

benign tumor and nonmalignant neoplasm both are nouns.

Word	Noun	Adjective	Verb	Adverb
benign tumor	Yes	No	No	No
nonmalignant neoplasm	Yes	No	No	No

As nouns, benign tumor and nonmalignant neoplasm are synonyms defined as:

Other synonyms of benign tumor include benign tumour, nonmalignant tumor, nonmalignant tumour.

benign tumor (noun)	nonmalignant neoplasm (noun)
a tumor that is not cancerous	a tumor that is not cancerous