Melanoma is a type of skin cancer that can develop from common and atypical moles as well as healthy skin. It is caused by a mutation in pigmented skin cells, known as melanin. This melanin is produced and delivered throughout the skin by cells called melanocytes. Sometimes excess melanin and melanocytes cluster together, causing moles. Within these clusters, melanocytes may mutate or trigger surrounding cells to mutate, causing skin cancer.
Superficial spreading melanoma is the most common type of melanoma. While other melanomas are not likely to affect those under 50 years old, superficial spreading melanoma has a higher occurrence rate in this age group. This type of skin cancer grows along the top layer of skin. Because it takes such a long time for it to spread into deeper layers, it is very likely to be identified and treated before it becomes invasive.
The first sign is the appearance of a flat or slightly raised discolored patch that has an irregular shape and border. The color varies. You may see areas of tan, brown, black, red, blue or white. The melanoma can be found almost anywhere on the body, but is most likely to occur on the torso in men, the legs in women, and the upper back in both. This type of melanoma can occur in a previously benign mole, so be sure to monitor your moles for any physical changes.
Lentigo maligna melanoma grows on the top layers of skin until it eventually thickens and invades deeper layers. This type of melanoma is most often found in the elderly, but can occur in younger people who experience excessive sun exposure.
Warning Signs Monitor skin that is chronically exposed to sun, especially damaged skin on the face, ears, arms, and upper torso. Look for flat or mildly elevated growths that have an irregular shape and are tan, brown or dark brown.
Acral lentiginous melanoma appears under the nails, on the soles of the feet, and on palms of the hands. Rather than developing within isolated clusters of mutated melanin like other skin cancers, this form of melanoma is most often found in skin that contains higher concentrations of melanin throughout the entire body.
Warning Signs People often do not notice acral lentiginous melanoma because it develops in areas that are commonly overlooked. Keep a careful watch for black or brown discoloration under the nails, on the soles of the feet, and on palms of the hands.
Nodular melanoma is the most aggressive form of melanoma. Unlike other types, it immediately spreads deep inside the skin. Appearing as hard bumps, nodular melanoma most frequently develops on the torso, legs, arms, and scalp. It is most common in men and elderly populations.
Warning Signs Keep a close watch for bumps on the skin that grow in unusual colors, such as black, blue, gray, white, brown, tan, or red.