Biopsy: The First Step

As a general rule, excisional biopsies are the best procedures for lesions suspicious for melanoma because they are designed to remove the entire lesion. The pathologist needs to look at a representative specimen to make the diagnosis of melanoma and to determine the features that predict its behavior. Excisional biopsies are usually relatively painless. After a local anesthetic is administered, the suspicious spot and a small margin around it are removed, and a few stitches are taken to close the wound. You can resume most activities a few days later.In certain circumstances other types of biopsies may be appropriate.

If the lesion is small and/or located in a cosmetically sensitive area, such as your face, a deep shave biopsy may be performed. In this procedure, after a local anesthetic is injected, the spot is shaved off with a razor blade. A punch biopsy may be used for a very small lesion and a punch biopsy or an incisional biopsy may sometimes be used in the case of a large lesion. In the first technique, all, or the most alarming part of the lesion, is “punched out” with a cookie cutter-like instrument. In the second, a small portion of the spot is cut out with a scalpel. With either method, disturbance to the appearance of the face, for example, is minimal. A technique called the MOHs procedure is sometimes used with melanoma biopsies and definitive removal, but is better suited for squamous and basal cell cancers. Research in 2010 showed deep punch biopsies to provide more accurate results than shave biopsies. But excisional is still the optimal method for getting the best margins.

One of the myths about melanoma is that a biopsy will stir up the melanoma cells and cause them to infiltrate the body. No evidence indicates that this will happen. The concern with any biopsy technique other than an excisional one is that the piece of skin cut will not include all of the lesion. This may make it difficult to know the extent to which melanoma has penetrated the skin, and consequently to determine its stage accurately.

What Should I Ask About A Skin Growth I Am Concerned About?

Here are some questions to ask and answers to look for when you see a doctor about a suspicious skin growth.

  1. What do you think this thing is? (Make sure your concern over it is taken seriously.) Most often the diagnosis will be something like seborrheic keratosis (which is a benign lesion) or an ordinary mole.
  2. (If the doctor says that no biopsy is necessary.) Are you sure this lesion is benign? Do you think it’s sufficient simply to keep an eye on the lesion? Ascertain the doctor’s degree of comfort with the diagnosis. If the doctor dismisses the growth as nothing worrisome, yet you have a gut feeling that it needs to be checked further, get it done.
  3. If you think it might be a melanoma, do you plan to do an excisional biopsy? If not, why not?
  4. When will the results of the biopsy be available? A week is usually enough time to make a determination.
  5. Who will perform the pathology? When will I have the results?

Source: Poole, Catherine, Guerry, DuPont, M.D., Melanoma Prevention Detection and Treatment, New Haven: Yale University Press, 2005.

UPDATED: June 6, 2014