Acanthosis nigricans

Last revised by Henry Knipe on 21 Nov 2022

Acanthosis nigricans is a cutaneous disorder characterized by symmetric hyperpigmented velvety plaques on the neck, axillae, antecubital and popliteal fossae, inframammary, and groin areas. It is associated with acquired lipodystrophy.


The benign form of acanthosis nigricans is associated with insulin resistance and diabetes. The malignant form is associated with adenocarcinoma (e.g. the stomach, ovary, kidney, bladder, bile duct, pancreas).

Histopathology of acanthosis nigricans shows papillomatosis and hyperkeratosis of skin.

Treatment and prognosis

The malignant form can regress after treatment of the cancer while the therapy of choice for the benign form is debatable but weight loss is considered first line.

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