Hematoxylin-eosin–stained sections showed hyperkeratosis, papillomatosis, and irregular acanthosis with minimal basilar hyperpigmentation.
Acanthosis nigricans is a symmetrical, velvety, papillomatous, gray-brown to black thickening of the skin that can be classified as benign and malignant, depending on the associated systemic disease. Associated findings include acrochordrons (skin tags), increased skin fold markings, and papillomas at the affected sites.1
Symmetrical Black Plaques on the Toes. Arch Dermatol. 2000;136(6):791-796. doi: