Skin cancer usually develops on sun-exposed areas of the skin, but it may also appear on areas not often exposed to sunlight. Common places where the disease arises include the scalp, face, lips, ears, neck, chest, shoulders, arms and legs. Less common places for skin cancer may be on the palms, beneath the fingernails, the spaces between the toes, under the toenails or in the genital region, according to the Mayo Clinic.
Basel Cell Carcinoma Signs
Basel cell carcinoma is the most common type of skin cancer. It's easily treated and usually caught on time because it can lie dormant over a long period, even for years. But medical treatment should be sought when seeing the first possible signs. Like any cancer, it can spread to other body tissues as soon as it becomes active, the American Cancer Society (ACS) notes. Basel cell skin cancers can take the form of pearly or waxy bumps that appear on the face, ears and neck. They can also be flat and flesh colored or brown scar lesions that show up on the chest or back.
Squamous Cell Carcinoma Signs
Squamous cell carcinoma is more likely to spread than a basal cell growth, but it can be treated easily upon early detection. Hard, red nodules may develop on the face, lips, ears, neck, hands or arms. Lesions that are flat, scaly or have a crusted surface may also be signs of squamous cell carcinoma and appear on the same areas.
Melanoma Signs
Melanoma is the most serious form of skin cancer and needs to be treated early because it can often be fatal. Melanoma can appear anywhere on the body or from an existing mole. It often appears on the trunk, head or neck of men and on the arms or legs of women. There are several warning signs. Melanoma can develop as a simple mole that changes color or size. It may bleed. It might appear as a small lesion that has an irregular border with different colored spots that may be blue, blue and black, red or white. The growth may also show up as a shiny, hard bump or a large, brownish spot with dark speckles. Any unusual dark lesion on the body may be an indication of melanoma and should be checked out. The ACS recommends the "ABCD rule." Asymmetry is when one half of the mole does not match the other half. Border irregularity may have irregular edges instead of being smooth. The color of the mole is not the same all over. The diameter of the mole is larger than one-quarter inch.
Rare Type Signs
There are rare skin cancers that are aggressive and need to be treated immediately when noticed. Kaposi sarcoma may develop in people with weakened immune systems, the Mayo Clinic explains. It causes red or purple patches on the skin and mucous membranes. Merkel cell carcinoma develops as a hard, shiny bump on sun-exposed areas. Sebaceous gland carcinoma grows as a hard and painless nodule anywhere on the body.
