Various terms may be used to describe skin cancers involving different skin-cell types, which may demonstrate different characteristics. Non-melanoma skin cancers frequently develop in sun-exposed areas of the skin. The exact cause of melanoma is unclear, but over-exposure to UV radiation, including artificial tanning booth treatments, can be a serious risk factor. Melanoma has the potential to metastasize to any organ through the blood and lymphatic routes, including to the lungs and the brain.

Basal cell carcinoma commonly develops on sun-exposed areas, especially on the face. Initially, it may take the form of a small, smooth, translucent, pigmented papule or nodule, but it eventually becomes an ulcerative lesion.

Squamous cell carcinoma can be invasive. It may appear as a rough, scaly, and possibly inflamed or bleeding tumor. Exposed upper extremities and facial areas are common sites for such carcinomas.

Different types of malignant melanoma differ greatly in their clinical presentations and other aspects. In general, the ABCD mnemonic may be used as a reminder when assessing a suspected melanoma:

• Asymmetric lesion with uneven elevations
• Border irregularity
• Color with various shades of red, white, and blue within a lesion
• Diameter greater than 6 mm (not a significant sign, as early-stage melanomas can be smaller)

1. Advocate skin cancer prevention, regular sunscreen application, and routine skin examination. Closely watch for changes in the size and color of any moles, including using the ABCD mnemonic as a reminder.
2. Informing patients, when applicable, of the risk and predisposing factors for skin cancer can be one of the nurse's functions.
3. Teach self-care skills after treatment (e.g., excision or radiation) and prevention of cancer recurrence.
4. Advocate for safe sun exposure and routine use of sunscreen products recommended by dermatologists, which often include those labeled as “broad-spectrum” agents.

1. Sunscreens are rated according to the sun protection factor (SPF), which measures their effectiveness in filtering or blocking UVB radiation.
2. Patients can be taught to use the ABCD mnemonic to monitor their skin lesions. Advise them to seek further evaluation if a lesion such as a mole becomes asymmetrical with an irregular border or bleeding, darkened or changing in color, and increased in diameter.

Sun exposure can cause degenerative changes in the skin. UVB radiation is believed to have carcinogenic effects, and ultraviolet-A (UVA) radiation adds to that effect. Many skin cancers are thought to be directly or indirectly induced by prolonged sun exposure, damage from which is cumulative in nature.