Precancerous Skin Lesions

Skin malignancies often start as precancerous skin lesions. Treating these lesions during this early stage can eliminate the need for more invasive procedures later and reduce the possibility of malignancy and metastasis. There are four primary types of skin lesions which include Solar or Actinic Keratosis, Atypical Melanocytic Hyperplasia, Atypical Fibroxanthoma (AFX), and Melanoma In Situ/Lentigo Meligna.

Type 1: Solar/ Actinic Keratosis

An actinic keratosis is a very common precancerous skin lesion that is usually the result of excessive sun exposure. It typically begins as a red, rough, scaly area of skin or may appear similar to a wart. The size of the lesion can range from a pencil point to a pencil eraser. An actinic keratosis can become easily irritated when rubbed by clothing and may be sensitive to the touch.

Although actinic keratoses occur quite frequently among individuals who spend time outdoors or use tanning beds, only about 5 percent of these lesions become skin cancer. Squamous cell carcinoma is the most common form of skin malignancy that develops from an actinic keratosis. In many cases, the malignancy does not develop until years after the initial lesion appears and can usually be prevented with early treatment.

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Type 2: Atypical Moles/ Atypical Melanocytic Hyperplasia

Approximately 10 percent of Americans have a dysplastic or atypical mole, a condition referred to as atypical melanocytic hyperplasia. Although most atypical moles never become malignant, they are considered a precancerous skin lesion and can be an early indicator of a potentially deadly form of skin cancer known as melanoma that affects up to 40,000 people in the United States each year.

Atypical moles tend to be larger than benign moles. They may be asymmetrical, have ragged or irregular borders, and be multiple shades of tan, brown, or pink. These moles may often change in size, color, fade, or become flat with the surrounding skin over time. When examined under a microscope, the mole will show cellular characteristics between a benign mole and melanoma. Those at greatest risk for developing melanoma have a history of excessive sun exposure or tanning, fair skin or heavy freckling, and multiple atypical moles.

Anyone with an atypical mole or a skin lesion that becomes symptomatic or does not resolve should consult a dermatologist to determine if the area is precancerous. Many of these lesions can be treated with in-office procedures that are non-invasive or minimally invasive.

Type 3: Atypical Fibroxanthoma (AFX)

An atypical fibroxanthoma, also known as an AFX, is an uncommon tumor that has the potential to metastasize aggressively if not treated. This type of tumor is most often seen on sun-exposed areas, including the scalp and ears. Elderly, white males are most at risk for developing an AFX. To reduce the possibility of metastasis, treatment for AFX tumors includes wide local excision, Mohs micrographic surgery, or curettage and desiccation.

Type 4: Melanoma In Situ/Lentigo Meligna

This type of lesion only affects the outer layer of skin and is not life threatening. Melanoma in situ, also known as lentigo meligna, has a five percent chance of developing into an invasive malignant melanoma over a 50-year period. Despite the low risk, excision is still the standard of care. In most cases, a 5 mm margin beyond the lesion is excised since the borders can extend beyond what is visible. A more conservative excision may be used for lesions on the face to minimize scarring and deformity. Elderly patients may prefer an approach of careful observation since the risk of the lesion developing into melanoma is so low.

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