Mohs micrographic surgery
Mohs micrographic surgery is a specialized technique used with the intent to achieve the narrowest margins necessary to avoid tumor recurrence, while maximally preserving cosmesis. It is best suited to management of tumors in cosmetically sensitive areas or for tumors that have recurred after initial excision (e.g., eyelid periorbital area, nasolabial fold, nose-cheek angle, posterior cheek sulcus, pinna, ear canal, forehead, scalp, fingers, and genitalia).[9,10] It is also often used to treat tumors with poorly defined clinical borders.
Mohs micrographic surgery requires special training. The tumor is microscopically delineated, with serial radial resection, until it is completely removed as assessed with real-time frozen sections. Noncontrolled case series suggested that the disease control rates were superior to other treatment methods for BCC.[9,11,12] However, as noted in the section on excision, the disease control rate was not clearly better when directly compared to surgical excision of facial BCCs in a randomized trial of primary BCCs.
Radiation therapy is particularly useful in the management of patients with primary lesions that would otherwise require difficult or extensive surgery (e.g., nose or ears). Radiation therapy eliminates the need for skin grafting when surgery would result in an extensive defect. Cosmetic results are generally good, with a small amount of hypopigmentation or telangiectasia in the treatment port. Radiation therapy can also be used for lesions that recur after a primary surgical approach. Radiation therapy is avoided in patients with conditions that predispose them to radiation-induced cancers, such as xeroderma pigmentosum or basal cell nevus syndrome.
As noted above, radiation therapy has been compared to excision in a randomized trial that showed better response and cosmesis associated with surgery.[5,6]
In a single-center randomized trial, radiation was superior to cryotherapy in local control at 2 years in 93 patients with primary BCCs. Patients were randomly assigned to receive either EBRT (130 kV x-rays, dosimetry depending upon lesion size) or cryotherapy (two freeze-thaw cycles with liquid nitrogen by spray gun). Patients with lesions on the nose or ear were excluded, since the investigators felt that electron beam therapy is the treatment of choice in these locations. By 1 year, the recurrence rates in the radiation and cryotherapy arms were 4% and 39%, respectively, in a per-protocol analysis. The investigators did not perform a statistical analysis, but the authors of a systematic literature review calculated a relative risk of 0.11 in favor of radiation (95% CI, 0.03-0.43).[Level of evidence 1iiDiv]
Curettage and electrodesiccation
This procedure is also sometimes called electrosurgery. It is a widely employed method for removing primary BCCs, especially superficial lesions of the neck, trunk, and extremities that are considered to be at low risk for recurrence. A sharp curette is used to scrape away the tumor down to its base, followed by electrodesiccation of the lesion base. Although it is a quick method for destroying the tumor, the adequacy of treatment cannot be assessed immediately since the surgeon cannot visually detect the depth of microscopic tumor invasion.