Biomaterial Database

Submicroscopical aspects of the melanogenesis and malignant melanomas. 1982

H Klug

The most important pigment of the human organism is the melanin. After a short representation of the most essential reactions of the biosynthesis of eu- and pheomelanins there are discussed some aspects of the formation of melanosomes as well as exhibited the structure of eumelanosomes and pheomelanosomes. In the tumour cells of the most melanotic malignant melanomas there can be observed clearly either eumelanosomes or pheomelanosomes. Therefore, two types (Type A and Type B) have been distinguished. One typical tumour cell of both types has been characterized ultrastructurally. A retrospective analysis of electron microscopically investigated melanomas which have been ascertained histologically shows that tumours containing eumelanosomes are more frequent than those with pheomelanosomes.

UI	MeSH Term	Description	Entries
D008543	Melanins	Insoluble polymers of TYROSINE derivatives found in and causing darkness in skin (SKIN PIGMENTATION), hair, and feathers providing protection against SUNBURN induced by SUNLIGHT. CAROTENES contribute yellow and red coloration.	Allomelanins,Melanin,Phaeomelanins
D008544	Melanocytes	Mammalian pigment cells that produce MELANINS, pigments found mainly in the EPIDERMIS, but also in the eyes and the hair, by a process called melanogenesis. Coloration can be altered by the number of melanocytes or the amount of pigment produced and stored in the organelles called MELANOSOMES. The large non-mammalian melanin-containing cells are called MELANOPHORES.	Melanocyte
D008545	Melanoma	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)	Malignant Melanoma,Malignant Melanomas,Melanoma, Malignant,Melanomas,Melanomas, Malignant
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man