The medical importance of moles has to do with its relationship with melanoma , which is the malignant version of a mole. When melanoma is diagnosed early it has a simple and effective surgical treatment but late diagnosis of metastases are frequent and mortality is high. The importance of moles in relation to melanoma is threefold :
1. Moles are risk markers for melanoma: melanoma is more common in people with many moles and / or atypical moles.
2. Moles can be simulators of melanoma: digital dermatoscopy helps us differentiate atypical moles from incipient melanomas because we see structures and colors that are not obvious to the naked eye and we can monitor their evolution and see early on which moles present problematic changes.
3. Some moles can be precursors of melanoma: some melanomas arise from healthy skin (like a new mole) but others derive directly from a previous mole, stable for years, which at a given moment begins to grow and change, and degenerates into melanoma.
With these clear concepts in mind we can better understand what it is and why it is worth a mapping of the moles with digital dermatoscopy .
What is a polka dot mapping?
It is the obtaining, in a systematized and orderly manner, of a set of panoramic and dermatoscopic images of most of our moles , which are archived to facilitate our subsequent surveillance.
The mapping can be partial if we just include the specific areas with more moles (for example, the back) or total, in which we include almost the entire cutaneous surface of the patient. The total mapping is more informative, since not always the melanoma appears where the patient had more moles or the most atypical.
Who should do a polka dot mapping?
Mole mappings are especially indicated in people at higher risk of melanoma and / or more difficult to monitor. This includes patients with many moles and / or atypical moles , people with personal and / or family history of melanoma, and people with fair skin, freckles, blond or red hair, light eyes, difficulty in tanning and easy to burn with Sun.
How is it done?
Currently we have modern digital dermatoscopy equipment with high definition image that allow us to take, archive and compare panoramic images (by sectors) and dermatoscopy (individual moles). Obviously, not all mappings are the same.
Factors to consider in the quality and precision of the mapping are:
- The image quality of the equipment
- Experience in the interpretation of dermatologist images
- The number of panoramic and dermatoscopy images included.
A more comprehensive mapping consumes more time but is more informative for monitoring. Personally I prefer this option.
How often should it be repeated?
It depends on the risk profile of the patient and the type of moles he has. An annual review may be sufficient for most patients. In very high risk patients, revisions can be considered every 6 to 9 months.
To facilitate the early detection of nodular melanomas, we should always facilitate an immediate review if the patient observes a new mole with rapid growth as well as changes or discomfort not justified in a mole.