<unk>  may take on many different appearances, one of the most common being a change in the color, or pigmentation, of the skin.
Drug-induced pigmentation
Chemotherapy-induced hyperpigmentation
Neurocutaneous melanosis
Phakomatosis pigmentokeratotica
Melanocytic nevus
Riehl melanosis
Smoker's melanosis
Congenital melanocytic nevus