There is generally little difference between a nodule and a mass, and when a mass is present in the body, it can be referred to as either a nodule or a mass. If there is a difference between the two, a nodule is usually a relatively small mass and a mass can be either a small mass or a larger mass. Nodules and masses, when they occur in a person, are first determined to be benign or malignant. If the mass is large and has symptoms of pressure, or if it causes biochemical changes, surgery may also be required. If the benignity of the mass is confirmed before surgery or if the possibility of malignancy is very high before surgery, surgery is required to remove the mass.