nonmalignant neoplasm vs benign tumor

nonmalignant neoplasm and benign tumor both are nouns.

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

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

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

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