nonmalignant tumour vs benign tumour

nonmalignant tumour and benign tumour both are nouns.

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

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

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

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