keratosis nigricans vs acanthosis nigricans

keratosis nigricans and acanthosis nigricans both are nouns.

Word	Noun	Adjective	Verb	Adverb
keratosis nigricans	Yes	No	No	No
acanthosis nigricans	Yes	No	No	No

As nouns, keratosis nigricans and acanthosis nigricans are synonyms defined as:

keratosis nigricans and acanthosis nigricans: a skin disease characterized by dark wartlike patches in the body folds; can be benign or malignant

keratosis nigricans (noun)	acanthosis nigricans (noun)
a skin disease characterized by dark wartlike patches in the body folds; can be benign or malignant	a skin disease characterized by dark wartlike patches in the body folds; can be benign or malignant