Let’s follow that mole
Suppose you have many moles and are you are worried that one of them might be a melanoma. You make an appointment with your dermatologist who examines not only the moles that concern you, but all of your skin lesions.
The dermatologist tells you that everything you were concerned about was benign, but she says that she is concerned about a spot on your lower back that you did not even know you had.
She says: “Let’s follow that mole. Come back in a few months and we will see if it changes.”
Why follow a suspicious mole and not just take it off?
Moles can often have atypical features on the clinical examination, but are found not to be melanoma once they are removed and examined under the microscope by the pathologist. Sometimes a mole looks very suspicious for melanoma and needs to be removed. More frequently however, a mole is in the grey zone: It has some atypical features that makes the dermatologist not want to dismiss it as benign, but not enough features to make the doctor think that it is really a melanoma.
Think of a scale from 1-5. Five is a melanoma. One is absolutely benign. What about the lesions that are 3 and 4? Should they be removed or followed?
If you have just a few moles, it may make sense just to remove the lesion. However, patients with funny moles might have numerous lesions (50-200). They might also have a number of scars from prior excisions of moles which turned out to be benign.
This patient said his back looked like a minefield and stopped going for exams because he was tired of having more procedures and more scars.
Another reason to follow a mole is if the lesion is in a cosmetically sensitive area.
This patient did not want a mark on his nose from a biopsy if it was not absolutely necessary.
How should one follow a mole?
When I started out in dermatology, I would measure the size of the mole and note any specific features that I saw by just looking at it. Later I would take photos of the moles and try to pick up subtle changes. However, unless there was dramatic change, it was difficult to decide if the mole needed to be removed.
I now follow moles using high quality dermoscopic photography. Dermoscopy is a technique that uses an instrument with which the examiner can see pigment patterns in a mole. There are patterns that are benign and the examiner can be confident that the mole does not need to be removed. When there are deviations from these benign patterns or when specific structures are present, the examiner should be concerned that a melanoma might be present. When I see a mole that deviates from the benign dermoscopic patterns, but not enough to really think the lesion is a melanoma, I might suggest following the lesion with high quality dermoscopic photography.
Short-term dermoscopic monitoring of pigmented lesions is safe and does not increase the risk of a bad outcome should the lesion later prove to be a melanoma. Three to 4 months is the usual initial waiting period. I will biopsy or remove the spot if I see a change while following the lesion with high quality dermoscopic photographs.
The pigmented spot on this patient’s nose changed over several months. It grew and became more granular. The lesion was biopsied and showed an early melanoma.
Harry Goldin, M.D.