nonmalignant neoplasm vs benign tumour

nonmalignant neoplasm and benign tumour both are nouns.

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

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

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

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