While laser treatment is commonly offered and may require several appointments,[citation needed] other dermatologists think lasers are not the best method for removing moles because the laser only cauterizes or, in certain cases, removes very superficial levels of skin. Moles tend to go deeper into the skin than non-invasive lasers can penetrate. After a laser treatment a scab is formed, which falls off about seven days later, in contrast to surgery, where the wound has to be sutured.[citation needed] A second concern about the laser treatment is that if the lesion is a melanoma, and was misdiagnosed as a benign mole, the procedure might delay diagnosis.[citation needed] If the mole is incompletely removed by the laser, and the pigmented lesion regrows, it might form a recurrent nevus.[citation needed]