nonmalignant tumour vs benign tumor

nonmalignant tumour and benign tumor both are nouns.

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

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

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

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