A malignant neoplasm derived from cells that are capable of forming melanin, which may occur in the skin of any part of the body, in the eye, or, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or malignant lentigo. Melanomas frequently metastasize widely, and the regional lymph nodes, liver, lungs, and brain are likely to be involved. The incidence of malignant skin melanomas is rising rapidly in all parts of the world. (Stedman, 25th ed; from Rook et al., Textbook of Dermatology, 4th ed, p2445)
A radioactive element of the alkaline earth series of metals. It has the atomic symbol Ra and atomic number 88. Radium is the product of the disintegration of URANIUM and is present in pitchblende and all ores containing uranium. It is used clinically as a source of beta and gamma-rays in radiotherapy, particularly BRACHYTHERAPY.
D006801
Humans
Members of the species Homo sapiens.
Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man