Widespread acanthosis nigricans. This implies concurrence of an internal malignancy.
Confluent papillomatosis of the lips and buccal mucosa.
Bilateral involvement of the axillae in this obese young man with an endocrine disorder.
The neck is a favorite site.
Closely set tiny papules in linear array.
Lesions situated over joints. Note how dark are the fingers in contrast to the rest of the skin.
Pigmented plaque with mammillated surface.
Pigmented, slightly elevated plaque with a gently papillated smooth surface, in this instance punctuated by atrophic striae.
Polypoid excrescences, as well as subtle papules. Grooves that traverse plaques represent accentuation of skin lines.
Ill-defined plaque, thrown into folds, made up of prominent, smooth-surfaced papules, some of them polypoid.
Pigmented plaque in which skin folds are accentuated.
Acanthosis nigricans: Brown papules, some of which have become confluent to form a plaque, are intersected by lines normal for skin. The dark brown macule is a Clark's nevus.