Chapter 1. Acanthosis Nigricans

Integration: Unifying Concept

Whether acanthosis nigricans is a consequence of an endocrine disorder or of a malignant neoplasm in an internal organ, the morphologic attributes are the same, clinically and histopathologically. When the cause of acanthosis nigricans is remedied, whether by treatment of the endocrine abnormality or by excision of a malignant neoplasm, the lesions of acanthosis nigricans wane and may disappear altogether.

The morphologic features of the confluent and reticulated papillomatosis of Gougerot and Carteaud seem to be those of a muted expression of acanthosis nigricans on an anterior aspect of the trunk.

The mechanism whereby acanthosis nigricans and its variants come to be formed is not known, but in some patients, evidence implicates insulin as an etiologic factor (insulin resistance). In patients with acanthosis nigricans who harbor an internal malignancy, humoral growth factors produced by the neoplastic cells may be important in the formation of the skin lesions.