nonmalignant tumor vs benign tumor

nonmalignant tumor and benign tumor both are nouns.

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

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

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

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