Skin cancers are among the most common cancers afflicting mankind and there are a variety of risk factors including environmental exposures, genetic predisposition, radiation exposure and immunosuppression. Skin cancers can be broadly divided into melanoma and nonmelanoma skin cancers (basal cell carcinoma and squamous cell carcinoma. In addition, skin appendage cancers (arising from sweat glands, hair follicles and sebaceous glands) may involve the skin. Any individual with a lesion that does not go away or changes or that is at all suspicious should be evaluated and possibly biopsies.
Basal Cell Carcinoma (BCCA)
Basal cell carcinoma is the most common type of skin cancer. In general these skin cancers occur in sun exposed areas and more than three-fourths are discovered in the head and neck region. These cancers are generally slow growing and rarely metastasize (spread). Sun exposure particularly during childhood and adolescence is the greatest risk factor. Other risk factors include ionizing radiation, immunosuppression and certain genetic syndromes.
Squamous Cell Carcinoma (SCCA)
Although less common then BCCA, SCCA is generally considered more serious. These tumors have a greater likelihood of spreading to other parts of the body (metastasizing). The incidence of SCCA has increased over the last decade. Like BCCA risk factors for SCCA include sun exposure, ionizing radiation, immunosuppression, certain viruses (human papilloma virus), genetics and chronic skin disorders (burns, sinus tracts, venous stasis wounds).
Premalignant lesions are skin lesions that have the potential of becoming malignant and include actinic keratosis, Bowen's disease, leukoplakia, erythroplakia, keratoacanthoma as well as radiation dermatitis. These lesions can be difficult to distinguish by appearance alone from invasive skin cancers.
Malignant melanomas are arguably the most lethal of the skin cancers, and may arise de novo or from a pre-existing "mole". Melanomas are usually but not always pigmented and can be difficult to distinguish from moles. Irregular borders, change in color or size, ulceration, and bleeding are all signs suggesting possible melanoma. These cancers have a relatively high potential to metastasize, and the prognosis is related to depth of invasion.
Diagnosis of Skin Cancers
The definitive diagnosis of skin cancer is by a biopsy and pathologic examination of the lesion under a microscope. Biopsy may be incisional where only a part of the lesion is surgically removed or excisional where the entire lesion is removed. Punch biopsy and shave biopsies may also be performed for some skin abnormalities suspicious for skin cancer. Shave biopsy should be avoided in melanoma.
The treatment of skin cancers is dependent on many factors. For most skin cancers surgical excision is probably the best for of treatment because it allows the diagnosis to be established as well as determining the status of the margins. Other forms of therapy including freezing the lesion (cryotherapy), cauterization, laser vaporization and topical chemical agents. Often premalignant appearing lesions such as actinic keratosis is treated with these later nonsurgical methods.
Frozen section is a technique where the margins can be frozen and examined at the time of the surgery to help to determine if the margins are clear. This technique is not perfect, but can be helpful in cases where the margins are hard to determine by observation alone. In addition, in larger sized lesions where local or regional tissue is to be used to reconstruct the defect frozen sections can be helpful.
Moh's surgery is a technique where the specimen is excised and the surgical margins are immediately inspected. Any residual tumor is resected and the process is completed until all margins are free of tumor. Most surgeons advocate the Moh's urgery only for large skin cancers, skin cancer in anatomically difficult locations, recurrent skin cancers or very poorly defined skin cancers.
Plastic surgeons are often called upon to treat skin cancers particularly when located in places such as the face where preservation of cosmesis or appearance becomes critically important. In addition, plastic surgeons are trained in scar camouflage techniques and the use of "flaps" to reconstruct the defects left by removal of the skin cancer.
Examples of Skin Cancer Reconstruction
- Breast Reconstruction
- Breast Reduction
- Cosmetic Surgeries
Facial Nerve Center
- Hand Surgery
Head and Neck Cancer
- Skin Cancer