ETYM New Lat.; Greek mela black + -oma.
Any of several malignant neoplasms (usually of the skin) consisting of melanocytes; SYN. malignant melanoma.
Highly malignant tumor of the melanin-forming cells (melanocytes) of the skin. It develops from an existing mole in up to two thirds of cases, but can also arise in the eye or mucous membranes.
Malignant melanoma is the most dangerous of the skin cancers; it is associated with brief but excessive exposure to sunlight. It is easily treated if caught early but deadly once it has spread. There is a genetic factor in some cases.
Once rare, this disease is increasing at the rate of 7% in most countries with a predominantly fair-skinned population, owing to the increasing popularity of vacations in the sun. Most at risk are those with fair hair and light skin, and those who have had a severe sunburn in childhood.