What is Acanthosis nigricans?
Acanthosis nigricans is asymptomatic, brown to black skin patches, with a velvety texture. Pedunculated skin tags often are present. The most common sites are the axillae, neck, and groin. If the patient is obese, the eruption may clear with weight loss or correction of the underlying endocrine disorder. Local treatment is not effective. Acanthosis nigricans usually is classified into 2 types: a benign form, not associated with malignancy, and a malignant form. Patients with the malignant form of acanthosis nigricans tend to be thin and older than 40 years of age, and their eruption is of recent origin. The most common malignancy associated with malignant acanthosis nigricans is abdominal adenocarcinoma, especially of the stomach.
