Melanoma Biopsy

A melanoma biopsy simply means that a sample of the suspected tumor is surgically removed and examined by a pathologist who can determine whether it is truly cancer (malignant), or whether it is not cancer (benign). A correctly performed biopsy is a crucial part of the confirmation (or dismissal) of a melanoma diagnosis, and its management².

Once the biopsy is taken it is sent to a pathologist who specializes in examining the sample and determining whether it is melanoma (malignant) or not (benign). They will examine the sample under a microscope and use various techniques including staining the sample.

• Benign melanoma: If the sample is benign, meaning that there is no melanoma, there is generally no risk and not much more to do other than to monitor the area with your doctor on a more regular basis.

• Malignant melanoma: If the pathologist determines that there is melanoma, your doctor will most likely want to make sure to take a wide area excision, if they haven’t already, to make sure they have removed the entire tumor. Depending on the Stage of melanoma, they may want to start you on a melanoma treatment.

Confirmation of malignant melanoma, however, does not determine the risk of whether the situation is serious. In fact in most cases, as long as the melanoma was caught early, it can be completely cured with surgical removal alone. However, to determine what the risk is, and what the next steps are, your doctor will use the melanoma staging system².

There are generally no risks of performing a wide area excisional biopsy other than the possibility of infection and scarring which can occur with any type of surgery. Some people believe that there is risk of any type of biopsy that doesn’t attempt to remove all of the suspected tumor (such as a punch biopsy or needle biopsy). The concern is that the “punching” or “poking” of the tumor can push melanoma cells further into the body, and facilitate its spread. So far there is no conclusive evidence to support this theory, however, if you are willing to tolerate the possible scarring from an excisional biopsy, this may be the best course of treatment to be on the “safe side.”

There are generally four types of melanoma biopsy:

Excisional melanoma biopsy

Melanoma Excisional Biopsy

This is the most common type of melanoma biopsy because it can simultaneously confirm (or refute) whether there is melanoma, and can determine the thickness of the tumor which determines the next steps in treatment^1,3. Additionally, the excisional biopsy often removes the entire tumor (if it is caught early) and hence can cure the melanoma completely.

This procedure is generally done as a simple surgery with a local anesthetic, and hence is often painless, though it may take several days to several weeks for the area of excision to heal. The size of the suspected tumor will determine how large of an excision needs to be made. If there is serious concern of melanoma, your surgeon will want perform a wide-area excision to remove the suspected tumor and about 1-2 centimeters of skin around it, which are called “margins.” The margins are taken as a precaution in case some of the melanoma cells have migrated past the edge of the tumor. Some doctors will do this in two steps: first a smaller excision to test if the suspected tumor is really melanoma, and if this is confirmed, then they will go back and remove even more of the area to make sure they have gotten all of the melanoma out.

Punch melanoma biopsy

Melanoma Punch Biopsy

This is less common because it is generally only good for determining whether a sample is melanoma, but cannot usually help determine the stage of melanoma or the next steps³. Hence it is usually used only when the suspected tumor is not likely to be melanoma or if it is in a spot where the scarring that can occur from an excisional biopsy can be a concern for the patient (for example, on the face). In this case, rather than doing a fully excisional melanoma biopsy, a small punch (a cookie-cutter like instrument) is used to “punch out” a small sample of the suspected tumor to be tested1. A local anesthetic is used and there is often very little discomfort and the healing time is short. If the results of the pathology come back confirming melanoma, your doctor will want to perform a wide area excision to remove the rest of the tumor.

Shave melanoma biopsy

Similar to a punch melanoma biopsy, this technique is less common and usually used when a melanoma is on the face, or in another highly visible spot where scaring from an excisional biopsy is a concern of the patient. A shave biopsy is otherwise not generally recommended as it often cannot help the doctor determine the thickness of the tumor and hence the best treatment options⁴. In a shave melanoma biopsy, a scalpel is used to shave off layers of the suspected tumor for testing. Since only a small layer of skin is removed, scaring is minimal. If the pathology results of the biopsy come back and melanoma is confirmed, either an excisional biopsy will be performed, or Mohs procedure will be used. Mohs is similar to shave biopsy in that a scalpel is used to remove layers of the tumor, and each layer is tested, until all of the tumor has been completely removed.

Needle melanoma biopsy

Melanoma Needle Biopsy

A needle melanoma biopsy is not generally used on a suspected tumor that is on the skin, but rather is sometimes used to test deeper tissue, lymph nodes or an internal organ to see if the melanoma has spread.

If you are concerned about the suspected tumor, but your doctor is not planning on taking a biopsy, ask them why not! If you have a “gut feeling” that something is wrong even if your doctor does not, it is ok to ask to have the suspected melanoma tumor remove and biopsied. If your doctor refuses, you should seek a second opinion. Keep in mind this fact: For skin cancers overall, dermatologists are much more accurate at correctly determining whether a suspicious mole is melanoma (89% of the time) vs. a general practitioner doctor (only 33% of the time)⁵, and hence getting a second opinion, especially from a specialist, is a smart thing to do.

Scaring from a melanoma biopsy is generally determined by the size of the sample that is taken. A larger sample, such as a wide-area excisional melanoma biopsy is more likely to cause scaring than a smaller sample such as a punch or shave melanoma biopsy. In either case, however, there are many ways to reduce scarring that you can try.

1. Poole, Catherine, Guerry, DuPont, M.D., Melanoma Prevention Detection and Treatment, New Haven: Yale University Press, 2005.
2. Swanson NA, Lee KK, Gorman A, Lee HN. Biopsy techniques: diagnosis of melanoma. Dermatol Clin. 2002;20:677–80. [PubMed]
3. Newton Bishop JA, Corrie PG, Evans J, Gore ME, Hall PN, Kirsham N, et al. UK guidelines for the management of cutaneous melanoma. Br J Plastic Surg. 2002;55:46–54.
4. Miller AJ, Mihm MC. Melanoma. N Engl J Med. 2006;355:51–65. [PubMed]
5. Brown SJ, Lawrence CM. The management of skin malignancy: to what extent should we rely on clinical diagnosis? Br J Dermatol. 2006;155:100–3. [PubMed]