Moles, also known as nevi, are common, benign skin growths formed by clusters of pigment-producing cells called melanocytes. While many seek mole removal for cosmetic reasons or if they become bothersome, it is not uncommon for a mole to appear to “come back” after the procedure. This can be unsettling, raising questions about removal effectiveness and the nature of the regrowth. Understanding the reasons behind this recurrence is important for managing expectations and ensuring appropriate follow-up care.
The Biology Behind Recurrence
Moles reappear because nevus cells, which form the mole, were not entirely eliminated during the initial removal procedure. Even microscopic remnants of these cells can multiply over time, leading to regrowth. This regrowth is a regeneration from residual cells, not the original mole physically “traveling back.”
Some moles are more prone to incomplete removal due to their structure. Dermal nevi, for instance, often have cells extending deeper into the dermis, beyond what is visible on the surface. If these deeper cells are not removed, they can proliferate and cause recurrence. The body’s natural healing processes can also play a role, reactivating pigment-producing cells.
How Removal Methods Influence Recurrence
The likelihood of a mole returning is influenced by the technique used for its removal. Methods that do not fully excise the mole’s deeper cellular components are more susceptible to recurrence. Shave excision, where the mole is shaved off at or just below the skin’s surface, is one such method. While it often results in minimal scarring and is effective for many superficial moles, it has a higher recurrence rate (11-33%).
This is because shave excisions may not reach the mole cells that extend into the deeper dermis, allowing them to regrow. In contrast, excisional biopsy involves surgically cutting out the entire mole, including its “roots,” and typically requires stitches to close the wound. This method aims for complete removal of the mole’s cells, significantly reducing the chance of recurrence. Laser removal and cryotherapy (freezing) are other methods; however, they may also have higher recurrence rates, especially for deeper moles, as they might not destroy all mole cells or penetrate sufficiently.
Recognizing a Returning Mole
Identifying a mole that has returned involves observing changes at or near the original removal site. A recurring mole might not look exactly like the initial one. It could appear as a darker spot, a small bump, or an area of discoloration in the treated area.
The reappearance might be due to residual cells or, in some instances, a new mole developing in the vicinity. Pay close attention to any changes in the size, shape, color, or texture of the returning growth. New symptoms such as itching, bleeding, or crusting should also prompt concern. While most recurring moles are benign, monitoring these characteristics helps distinguish a harmless recurrence from a potentially more concerning development.
When to Consult a Dermatologist
Professional medical attention is advised if a mole appears to return after removal. A dermatologist can assess the re-growing lesion and determine its nature.
Consult a dermatologist if the returning mole exhibits changes in appearance (asymmetry, irregular borders, varied color, increasing diameter, or evolution). While most recurrences are benign, a dermatologist can differentiate between a common returning mole and a more serious condition, such as melanoma, which can sometimes mimic a benign recurrence. Early evaluation provides peace of mind and allows for timely intervention if a concerning condition is identified.