The Conical-Shaped, Staged Laser Ablation Technique in the Removal of a Medium Sized Intradermal Nevus.

Dear Editor:

The removal of an intradermal nevus is a common procedure in the dermatology clinic. However, if the nevus is large (>3 mm), it is very difficult to remove without recurrence or scarring. If a nevus is removed too superficially, it will recur or appear blue, similar to a blue nevus. On the other hand, if a nevus is removed too deeply, the extensive ablation will result in scarring or prolonged erythema. To obtain complete removal of a mole with better cosmetic results, we introduced the conical-shaped, staged laser ablation technique using a CO2 laser.

We present a 38-year-old man with two intradermal nevi (3 mm and 8 mm in diameter) around the lip (Fig. 1A). The first laser operation was performed in the shape of a cone (Fig. 1B, Fig. 2B). The approximate size of the laser entrance hole was 50%∼70% of the diameter of the lesion, which preserves superficial epidermis as much as possible. The depth of ablation hole should be greater than the depth of the deepest part of the lesion, to completely removes the deepest part of the lesion and prevent recurrence. The deep components of the lesion are ablated as much as possible, resulting in a conical shape. The second laser operation was performed 40 days after the first operation to remove the crater-shaped remnants (Fig. 2C). The intradermal nevi were removed with a good cosmetic result (Fig. 2D).

Fig. 1

(A) Conventional ablation technique: if the laser cauterizes very superficial levels of skin, the mole will recur, whereas if the laser removes very deep levels of skin, there will be scarring. (B) Conical-shaped, staged ablation technique: at the first operation, the nevus cells in deep layers of the dermis are removed completely, while a large portion of epidermis is preserved as much as possible. The remnant nevus cells (red circle) will be removed completely with the second operation in a staged fashion.

Fig. 2

(A) Before treatment: intradermal nevi measuring 3 mm and 8 mm size around the lip. (B) After the first operation: the nevus cells in deep layers of the dermis are eliminated through the small hole. (C) Forty days after the first operation: the lesion has a crater shape. Scar shrinkage makes the lesion smaller. (D) Follow-up photograph (7 months after the first operation): two lesions are completely removed with a minimal scarring.

The advantage of the conical-shaped ablation technique is that more epidermis can be preserved than with conventional laser ablation, and the preserved epidermis may act as a “biological” dressing, protecting the underlying wound bed and supporting the newly forming epidermis. Because migration from the wound edge into center of each cell is important for reepithelization, preserving epidermis through conical-shaped method could be helpful for wound healing process1. The CO2 laser is preferred over the erbium-doped yttrium aluminium garnet (Er:YAG) laser, because the CO2 laser coagulates and shrinks collagens, and is able not only to control bleeding, but also to decrease the entrance hole size23.

Serial-staged excision of large solitary lesions may be used if the lesion is too large to be resected in one procedure or to minimize scarring4. If there is some difficulty in removing all of the lesion at the first conical ablation, a second laser operation may be needed. Because the remnant is small and located more superficially than the pretreatment lesion, the second operation can be performed more safely and easily.

The disadvantage of the conical-shaped staged laser ablation is that it could be bothersome for patients because of the staged fashion and it requires more techniques, compared to conventional cylinder shaped laser ablation.

In conclusion, the use of the conical-shaped, staged laser ablation technique is useful in the management of a medium-sized intradermal nevus. The technique may be utilized in the treatment of other benign lesions located beneath the normal epidermis.