• Skin biopsy specimens of acanthosis nigricans (AN) lesions were obtained from seven women with the polycystic ovary (PCO) syndrome and insulin resistance (IR). All the patients had normal thyroid function test results and fasting hyperinsulinemia with an exaggerated insulin response to oral glucose. Acanthosis nigricans lesions exhibited prominent deposits of glycosaminoglycan (GAG) consisting mostly of hyaluronic acid in the papillary dermis. Normal amounts of GAGs were found in control biopsy specimens obtained from areas of the skin not involved by AN and from skin of the nape of the neck or axillae in three normal women. These studies demonstrate that GAG deposition is a regular component of AN skin in patients with PCO and IR. The cause of these infiltrates remains to be determined.
(Arch Intern Med 1983;143:1145-1148)