Solar lentigo is a harmless patch of darkened skin resulting from local proliferation of melanocytes and accumulation of melanin within keratinocytes due to exposure to ultraviolet radiation. It is classically a flat, well-circumscribed patch. It can be round, oval or irregular in shape and may be slightly scaly.
Seborrhoeic keratosis is classically a benign warty or waxy plaque/ papule that appears during adult life as a common sign of aging skin. It is estimated that >90% of adults over 60 years old have them. They may arise on any area of skin except palms, soles and mucous membranes.
