Catching the change

March 1, 2007

If it is not growing, chances are it is not malignant. If it is growing, malignancy is possible. The problem is that all acquired nevi also have a growth phase, so growth cannot be used as a sole parameter.

Melanoma has to go through a period of growth before becoming clinically detectable, and doctors need to zero in on this growth period. There are several ways to achieve this, one expert said, speaking at the 65th Annual Meeting of the American Academy of Dermatology, here.

"One of our problems in the U.S. is that we set so much importance on the ABCDs, but the fact of the matter is that the ABCDs just don't work in discriminating a malignant melanoma from a benign dysplastic nevus. They are pretty good for your routine, common, average mole versus melanoma, but they just don't work for dysplastic nevi versus melanoma. Dermatologists have slowly begun to realize this, and that's why the 'E' for 'evolution' was recently added to the scheme, which really is a recognition that we need information on change," says James M. Grichnik M.D., Ph.D., director of the Melanocytic Diseases Center of the division of dermatology at Duke University Medical Center, Durham, N.C.

Dr. Grichnik explains that growth is a biologic indicator.

If it is not growing, chances are it is not malignant. If it is growing, malignancy is possible. The problem is that all acquired nevi also have a growth phase, so growth cannot be used as a sole parameter.

To identify growing lesions in his patients, Dr. Grichnik uses - and strongly advocates - total body photos (TBP). This method allows for the assessment of existing and new lesions anywhere on the body.

"I request baseline TBP (MoleMap CD) on my high-risk patients, and upon their return visit, if I am worried about a particular mole, I simply check the baseline images and know immediately if there was a change. In general, TBP may be repeated about every five years for younger adults and up to once every 10 years for the elderly population, but this decision is entirely dependent on how the patient's exam has changed," Dr. Grichnik says.

Dr. Grichnik recommends considering TBP for patients with numerous nevi, dysplastic nevi, and/or personal or family history of melanoma.

Dermoscopy dilemma

Dr. Grichnik says the other way to collect data on growth is to use dermoscopy, but two problems are associated with this method.

The first is that this method is lesion-specific, meaning that only selected current lesions are imaged, and there is no information on nonimaged or new lesions. The second problem is that this method offers only delayed growth information, meaning that a follow-up visit is required, and an eventual excision is delayed. He says that while this method is a good way to show a lesion is changing, there is a real risk in letting it grow.

Build a better mousetrap

Dr. Grichnik says that because normal moles also have a growth phase, it is important to devise a newer, better algorithm for identifying early melanomas.

Dr. Grichnik introduced the concept of the "smoking gun" - referring to lesions that have undergone growth, appear unusual and are nonuniform. He says that dermatologists need to look for an unusual lesion that is growing. If it looks like the other moles on the patient, chances are it is fine.

"Because melanomas are based on different mutations than the other moles on the patient, they are going to look a little bit different and they are going to be growing, and as they continue to develop, they will become more and more nonuniform. So if you have a growing lesion that doesn't match the other lesions on the patient, you need to seriously consider removing it. If it is also becoming nonuniform, it needs to be excised," Dr. Grichnik tells Dermatology Times.