Skin Cancer Surgery
Basal cell carcinoma, squamous cell carcinoma, and malignant melanoma are the common forms of skin cancer requiring surgical treatment. The cancer type, size, location, and histopathological features determine the treatment type advised by your dermatologist.
Simple excision is the cutting out of the tumor, with a scalpel or scissor, with a margin of healthy surrounding tissue. In preparing for skin cancer surgery, your dermatologist will first usually have performed a biopsy of the lesion and will know exactly what kind of skin cancer is present. During a pre-op meeting, your dermatological surgeon will review a complete medical history, including any need for antibiotics prior to surgery, medications taken, especially anticoagulants, and the presence of any implanted medical devices such as a pacemaker. Skin cancer surgery is an outpatient procedure performed under local anesthesia. On the day of your skin cancer surgery, you will be taken to a procedure room. After completing the informed consent, you will change into a gown and be positioned for the procedure. Your dermatological surgeon will mark the area and confirm the location by comparing with photographs taken previously. After that, the area will be numbed with injections of local anesthetic. Your dermatological surgeon will then prep the area with antiseptic, drape it, and start the surgery. Most skin cancers will be excised as an ellipse around the lesion, resulting in a linear scar approximately 2.5-3.0 times as long as the original lesion. This is necessary to close the wound without leaving unsightly bunching of skin (called “dog ears”). After cutting out the skin cancer and a margin of healthy tissue, your dermatological surgeon will consider how best to repair the defect. This can include closure with subdermal and superficial sutures, flaps, grafts, or allowing to heal by “second intent”, meaning without further closure. Most excisions are closed with buried resorbable sutures, such as Vicryl, and a superficial layer of Nylon sutures, which must be removed 1-2 weeks after the procedure. After repairing the defect, a dressing and antibacterial ointment will be applied to the wound and wound care instructions provided.
Mohs Micrographic Surgery
Mohs micrographic surgery is a procedure in which skin cancers are excised and immediately processed for review by light microscopy. The Mohs surgeon evaluates the tissue to confirm that all of the tumor has been removed. During this time the patient is bandaged and waits for the results. If the margins of the excised tissue is negative for tumor, then the resulting wound is repaired. If the margins contain residual tumor cells then an additional piece of tissue is excised (termed a “stage”). This process continues until the margins are negative for tumor. The key to Mohs surgery is that it achieves complete “histological control” of the margins, due to the method in which the specimen is excised and processed. Mohs surgery achieves the lowest recurrence rate and simultaneously spares the maximum amount of healthy tissue. This is especially important in cosmetically sensitive areas like the face.
Who should undergo Mohs surgery?
The decision as to which tumors should undergo Mohs surgery depends on the the nature of the tumor and the site. Established indications include:
- Recurrent basal cell carcinoma (BCC) or squamous cell carcinoma (SCC)
- BCC or SCC with clinically indistinct borders
- Lesions in “high-risk” areas of the face
- Cosmetically sensitive areas and areas with limited adjacent skin for repair, such as genitals, anal and peri-anal, hands, feet, and nail units
- Rapidly growing tumors
- Tumors >2cm in diameter
- Tumors with certain aggressive histological subtypes
- Tumors arising in sites of previous radiation treatment
- Tumors in immunosuppressed patients
- Patients with basal cell nevus syndrome.
What will happen before, during and after Mohs surgery?
The dermatological surgeon will first review with the patient all relevant pre-operative details and medical history, including need for antibiotic prophylaxis, evaluation of clotting parameters, and the presence of implantable medical devices.
On the day of surgery, the patient is situated in the procedure room, informed consent signed, the lesion marked, and photographs taken. The site is prepped and infiltrated with a local anesthetic, and the first “layer” excised at a 45 degree angle to the skin. The edges of the lesion and adjacent skin may be scored with a scalpel to preserve orientation. The surgical site is then temporarily bandaged while the tissue is processed and evaluated. Additional “layers” may be necessary until all of the tumor has been removed. Once the margins are “negative”, the surgeon will select an appropriate method to repair the wound, which may include primary closure, a flap or a graft. A dressing will be applied and wound care instructions provided.
Electrodesiccation and curettage
Electrodesiccation and curettage is the use of an electrosurgery device (the Conmed Hyfrecator is used at SOMA Skin & Laser) to generate an electric current to dehydrate/burn the tumor followed by scraping of the tumor with a curette. The area is first numbed with local anesthetic. This cycle of electrodessication and curretage is typically repeated three times, and includes a margin around the clinically apparent tumor. This method of treatment does not require suturing, but leaves a broad scar the shape of the area treated. The recurrence rate with electrodessication and curettage can be higher than with other methods. It is best used on superficial lesions (such as superficial basal cell carcinomas) or in elderly patients or those with comorbidities where the slightly increased recurrence risk is offset by the simplicity of the procedure.
Cryosurgery is the freezing of the tumor, typically with liquid nitrogen. Although large and deep tumors can be approached this way, cryosurgery is most often used for superficial cancers when excision cannot be performed and for actinic keratoses.