You are correct. Acanthosis nigricans is characterized by thickening and hyperpigmentation of the skin, most often in the axilla and neck areas. This case is an example of the most common type: obesity-related acanthosis nigricans. Although there is a subtype associated w/ malignancy, it is relatively rare. At the time the source article was published, there were no RCTs for the tx of acanthosis nigricans; however, many reports suggest that it will improve w/ tx of the underlying condition or by using topical retinoids.