benign tumor vs nonmalignant tumor

benign tumor and nonmalignant tumor both are nouns.

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

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

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

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