junctional naevusA flat or slightly raised, brown, hairless skin mole arising from pigment cells lying at the junction between the EPIDERMIS and the underlying true skin (CORIUM). Junctional naevi occur on any part of the skin. All coloured moles on the palms and soles are junctional naevi. About half of all MALIGNANT MELANOMAS arise from junctional naevi, but such malignant change is rare. Any alteration in the appearance of a pigmented mole should be reported at once.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005