NURS 443 Lecture Notes - Lecture 13: Melanin, Mycosis, Ctla-4
Malignant Skin Neoplasms
Skin cancer is the most commonly diagnosed cancer.4 Skin cancers are either nonmelanoma or melanoma. A
persistent skin lesion that does not heal is highly suspicious for malignancy and should be examined by a health care
provider. Early detection and treatment can often lead to a highly favorable prognosis. The fact that skin lesions are
so visible increases the likelihood of early detection and diagnosis.
Teach patients to self-examine their skin at least on a monthly basis. The cornerstone of skin self-examination is the
ABCDE rule,5 which is easy to teach and remember. Examine skin lesions for Asymmetry, Border irregularity,
Color change and variation, Diameter of 6 mm or more, and Evolving in appearance (Fig. 24-2). Emphasize that
lesions once flat and now raised, or once small and recently growing or changing in appearance, are warning signs
and should be examined by a health care provider.
Risk Factors
Risk factors for skin malignancies include having a fair skin type (blond or red hair and blue or green eyes), history
of chronic sun exposure, family history of skin cancer, and exposure to tar and systemic arsenicals.6 Environmental
factors that increase the risk of skin malignancies include living near the equator, outdoor occupations, and frequent
outdoor recreational activities. Behavioral factors such as using indoor tanning booths and outdoor sunbathing are
controllable risk factors for skin malignancies. Patients treated with oral methoxsalen (psoralen) and psoralen plus
ultraviolet A radiation (PUVA) may be at greater risk for melanoma.
Dark-skinned persons are less susceptible to skin cancer because of the naturally occurring increased melanin, which
is a sunscreen. However, although dark skin lowers the risk of melanoma, people with dark skin can develop
melanoma, most often on the palms, soles, and mucous membranes.
The Fitzpatrick classification of skin type can assist you in determining how a patient will respond or react to facial
treatments, and how likely they are to get skin cancer. This system classifies skin into six different skin types, skin
color, and reaction to sun exposure.
● •Type I (very white or freckled): Always burn
● •Type II (white): Usually burn
● •Type III (white to olive): Sometimes burn
● •Type IV (brown): Rarely burn
● •Type V (dark brown): Very rarely burn
● •Type VI (black): Never burn
Nonmelanoma Skin Cancers
Nonmelanoma skin cancers, either basal cell or squamous cell carcinoma, are the most common forms of skin
cancer.7 More than 2.2 million new cases are diagnosed every year. Nonmelanoma skin cancers develop in the
epidermis. They do not develop from melanocytes, the skin cells that make melanin, as melanoma skin cancers do.
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The most common sites for the development of nonmelanoma skin cancer are in sun-exposed areas, such as the face,
head, neck, back of the hands, and arms.
Although relatively few deaths are attributable to nonmelanoma skin cancer, the tumors have an inherent potential
for severe local destruction, permanent disfigurement, and disability. The most common etiologic factor is sun
exposure. Avoidance of exposure to the midday sun and the use of protective clothing and sunscreens beginning
early in life can prevent the formation of skin malignancies later in life.
Actinic Keratosis
Actinic keratosis, also known as solar keratosis, consists of hyperkeratotic papules and plaques on sun-exposed
areas. Actinic keratoses are premalignant skin lesions that affect nearly all of the older white population. These are
the most common of all precancerous skin lesions. The clinical appearance of actinic keratoses can be highly varied.
The typical lesion is an irregularly shaped, flat, slightly erythematous papule with indistinct borders and an
overlying hard keratotic scale or horn (Table 24-3).
Many forms of treatment are used, including cryosurgery, fluorouracil (5-FU), surgical removal, tretinoin (Retin-A),
imiquimod (Aldara), diclofenac (Solaraze), chemical peeling agents, dermabrasion, laser resurfacing, and
photodynamic therapy (PDT, with 5-aminolevulinic acid [5-ALA] or methyl aminolevulinate [MAL] followed by
light irradiation). (These treatments are discussed later in this chapter.) Any lesion that persists should be evaluated
for a possible biopsy.
Basal Cell Carcinoma
Basal cell carcinoma (BCC) is a locally invasive malignancy arising from epidermal basal cells. It is the most
common type of skin cancer and also the least deadly. BCC usually occurs in middle-aged to older adults. Clinical
manifestations are described in Table 24-3. The cancerous cells of BCC almost never spread beyond the skin (Fig.
24-4). However, if BCC is left untreated, massive tissue destruction may result. Some BCCs are pigmented with
curled borders and an opaque appearance and may be misinterpreted as a melanoma. A tissue biopsy is needed to
confirm the diagnosis.8
Multiple treatment modalities are used depending on the tumor location and histologic type, history of recurrence,
and patient characteristics. Treatment modalities include surgical excision, electrodesiccation and curettage,
cryosurgery, radiation therapy, topical or systemic chemotherapy, and photodynamic therapy. (These treatments are
discussed later in this chapter.) Electrodesiccation and curettage, cryosurgery, and surgical excision all have a cure
rate of greater than 90% when used correctly on primary lesions. Location and size are important factors in
determining the best treatment.
Squamous Cell Carcinoma
Squamous cell carcinoma (SCC) is a malignant neoplasm of keratinizing epidermal cells (see eFig. 24-1 available
on the website for this chapter). It frequently occurs on sun-exposed skin at the base of an actinic keratosis or
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Document Summary
Skin cancer is the most commonly diagnosed cancer. 4 skin cancers are either nonmelanoma or melanoma. A persistent skin lesion that does not heal is highly suspicious for malignancy and should be examined by a health care provider. Early detection and treatment can often lead to a highly favorable prognosis. The fact that skin lesions are so visible increases the likelihood of early detection and diagnosis. Teach patients to self-examine their skin at least on a monthly basis. Abcde rule,5 which is easy to teach and remember. Color change and variation, diameter of 6 mm or more, and evolving in appearance (fig. Emphasize that lesions once flat and now raised, or once small and recently growing or changing in appearance, are warning signs and should be examined by a health care provider. Behavioral factors such as using indoor tanning booths and outdoor sunbathing are controllable risk factors for skin malignancies.
