Lichen planus (LP) pigmentosus is a rare variant of cutaneous lichen planus (see this term) characterized by the presence of hyperpigmented lichenoid lesions in sun-exposed or flexural areas of the body.

A type of cutaneous melanoma localized to the palm, sole, or beneath the nail (subungual melanoma). Acral lentiginous melanoma starts as a slowly-enlarging flat patch of discoloured skin and usually displays a size above 6 mm and often several centimetres or more in diameter upon diagnosis and variable pigmentation with a mixutre of colors including brown, and blue-grey, black and red. The surface of the lesion is initially smooth but later in the course may become thicker and irregular, and may ulcerate or bleed.