Oral manifestations as a hallmark of malignant acanthosis nigricans

We present a case of malignant acanthosis nigricans (AN) that initially man ifested in the oral cavity. In the present report, the patient had typical clinical and histological findings of oral and esophageal AN, with subtle s kin changes, associated with a gallbladder adenocarcinoma. The importance o f the clinical oral examination is emphasized because the recognition of or al lesions led to the diagnosis of AN and to the following detection of the internal malignancy. Since the tumours associated with AN are highly malig nant, it is of the utmost importance to recognize the skin and mucous membr ane changes in adults.