Descriptions of these two terms in medical dictionaries and indeed in many studies are vague and sometimes confused. Even the etymology seems weird in that “neoplasia” comes from the Greek words “neo” (new) and “plasis” (formed). Usage adds the concept of “abnormal,” so a neoplasm is a new and abnormal growth. Neoplasms can be benign or malignant. However, the simplest concept is that neoplasia applies to a growth or tumor or piece of tissue, but dysplasia applies to the cells within an organ or growth.