Flat moles, or nevi, are common skin growths that can be safely and effectively removed when desired. Removal is sought for two primary reasons: cosmetic preference, especially when a mole is prominent, or medical necessity, when a mole exhibits features that suggest a potential health risk. A flat mole is a pigmented lesion that lies flush with the surface of the skin, making its removal a slightly different procedure than that for a raised mole.
Understanding Flat Moles
Flat moles are medically categorized as junctional nevi, distinguished by the location of melanocytes (pigment-producing cells). These cells cluster specifically at the dermo-epidermal junction, the boundary layer between the epidermis and the dermis. Because the clusters have not migrated deeper, the mole remains flat and macular, or spot-like. These lesions are typically dark brown to black and possess uniform color and distinct, regular borders. Flat moles are acquired lesions, meaning they develop after birth, and while they are benign, their surface location makes them a focus of skin cancer screening.
When Removal Becomes a Medical Necessity
While most flat moles are harmless, any changes in their appearance warrant an immediate medical evaluation due to the risk of melanoma, a serious form of skin cancer. Dermatologists use the well-established ABCDE criteria to screen pigmented lesions for features concerning for malignancy, helping identify moles that require closer attention and potential removal for diagnostic purposes.
The ABCDE criteria include:
- Asymmetry, where one half of the mole does not mirror the other half.
- Border irregularity, characterized by edges that are notched, blurred, or scalloped instead of smooth and defined.
- Color variation, involving the presence of multiple shades like tan, brown, black, red, white, or blue within the same lesion.
- Diameter larger than 6 millimeters, roughly the size of a pencil eraser, which raises suspicion.
- Evolving, which refers to any change in the mole’s size, shape, color, or elevation over time, or the development of symptoms such as itching or bleeding.
If a flat mole exhibits one or more of these signs, a dermatologist will recommend a biopsy, removing the mole or a portion of it for pathological analysis to definitively determine if cancerous cells are present.
Techniques for Mole Removal
The method chosen for removing a flat mole depends heavily on whether the lesion is suspected to be benign or malignant, as well as its depth. Full surgical excision is the most definitive technique, especially for any flat mole that is medically suspicious.
Surgical Excision
Surgical excision involves using a scalpel to cut out the entire mole, including a small margin of surrounding healthy skin, and extending deep enough to ensure complete removal. This procedure is performed under local anesthesia, and the resulting wound is closed with sutures, leading to a linear scar. The benefit of this technique is that it provides the entire tissue sample for a complete pathological analysis, which is non-negotiable for moles that meet the ABCDE criteria.
Shave Excision
For flat moles that are confirmed to be benign and are being removed for purely cosmetic reasons, a shave excision may sometimes be an option. Shave excision uses local anesthesia and a fine surgical blade to shave the lesion off at or just below the skin level. While generally preferred for raised moles, it carries a higher risk of recurrence or incomplete removal for flat moles compared to full excision.
Laser Removal
Laser removal is sometimes discussed for small, flat, and non-suspicious pigmented lesions, as it uses concentrated light energy to break down the pigment. However, this method is generally not the standard for flat moles because it destroys the tissue, meaning no sample is available for pathological analysis.
What to Expect After Removal
Regardless of the technique used, proper aftercare is necessary to promote healing and minimize the appearance of a scar. Immediately following the procedure, the site will be dressed, and patients are instructed to keep the area clean and moist, often by applying petroleum jelly and covering it with a fresh bandage. Limiting strenuous activity is often advised for a week or two, particularly if a full surgical excision involving stitches was performed, to prevent tension on the wound.
The initial healing phase, where a scab forms and falls off naturally, typically takes between one and three weeks. For full excisions, stitches are generally removed within one to three weeks, depending on the mole’s location. A scar is an unavoidable outcome: full excision results in a thin, linear scar, while a shave excision leaves a flat, pale mark.
Scar tissue will be red or pink at first, but it gradually fades and flattens over several months, sometimes taking a full year to mature. Protecting the site from sun exposure is important during this period, as ultraviolet radiation can darken the healing scar tissue, making it more noticeable. Follow-up appointments are scheduled to monitor the wound’s progress and discuss the final pathology results if a biopsy was performed.