The causes of acanthosis nigricans are generally broken down into two types:
- Benign, caused by obesity, a genetic condition or a hormone disorder
- Malignant, usually associated with a tumor
If acanthosis nigricans is seen, a full medical history is necessary to determine if it can be ascribed to a benign cause. If no benign cause can be determined, it is good practice to do necessary imaging to attempt to find a tumor, often in the pancreas or the adrenal glands.