What are the symptoms and signs?
Skin cancers are the mostcommon type of cancer people get. These cancers develop most commonly on sun-exposed skin including the backs of the hands and arms, upper trunk, face, nose, lips, ears, lower legs, and the hairless scalp. They much less commonly involve the nail bed, bottom of the feet, and the genital areas. Skin cancers are most common in people with lighter skin tones. There are three common skin cancers -- basal cell carcinoma, squamous cell carcinoma, and melanoma. Actinic keratoses are referred to as "precancers."
Actinic Keratosis (Precancers)
Actinic keratoses, or solar keratoses, occur in chronically sun-damaged skin. They are the precursors to squamous cell carcinomas (SCC). They tend to appear as reddish, brownish, or flesh-toned irregular, rough, scaly patches. People often have multiple lesions at the same time and a stinging sensation has been associated with them.
Basal Cell Carcinoma (BCC)
BCC is the most common type of skin cancer and has a predilection for sun-exposed skin. Tumors may appear as a pearly or waxy bumps usually with visible blood vessels (nodular BCC), or as a flat scaly reddish patch (superficial BCC) with a brown border, or as a hard or scar-like lesion (sclerosing BCC). Frequently BCCs can be itchy, often bleed, or in more advanced cases, ulcerate.
Squamous Cell Carcinoma (SCC)
SCC is the second most common skin cancer. Mostly, it occurs in sun-exposed skin arising from an actinic keratosis; however, it can also occur in sites of irradiation, and in burn or vaccination scars. SCC may appear as a scaly or crusty reddish nodule (typical SCC) or as an irregular, flatter, crusted erosion. Sometimes they appear to be small volcanos with heaped up shoulders surrounding a central horny core. SCCs may also be itchy, bleed, or ulcerate in the more advanced cases.
Although melanomas can develop anywhere on the body, they are most commonly seen in sun-exposed regions. Most melanomas develop as new lesions, but a few develop from preexisting moles. The most common areas where melanomas appear are the upper trunk and head and neck regions, and also on the lower extremities, especially in women. In people with darker skin tones, melanomas tends to occur on the palms and soles or may involve the nail tissues, appearing most commonly as a pigmented longitudinal linear streak. Melanoma may appear as a pigmented spot with an irregular border, different colors, and/or asymmetry. It may also present as a mole that changes in size, color, or shape. Or, it could appear as a brownish spot with darker speckles, or a bluish-white area, or a multi-colored lesion. Furthermore, melanomas may appear as irregular pigmented areas on the palms, soles, fingernails, toenails, or mucosal surfaces. Finally, the much less common amelanotic melanomas don't have much color and can be pinkish, purplish, or flesh-toned; hence, they can be very difficult to diagnose.
Less Common Skin Cancers
Kaposi's sarcoma is a rare skin cancer which develops from the skin's blood vessels and presents as reddish or purplish patches or nodules. It usually may develop in individuals with a weakened immune system, but it can also occur in adults of Mediterranean ancestry.
Merkel cell carcinoma is a rare, aggressive skin cancer of neuroendocrine origin usually occurring in older people. It appears as a flesh-toned or reddish-bluish shiny nodule on the face or head and neck areas.
Medically reviewed by Jay B. Zatzkin, MD; American Board of Internal Medicine with subspecialty in Medical Oncology
"Screening and early detection of melanoma"