There are 2 main types of adrenal cortex tumors: benign (non-cancerous) and malignant (cancers). Most of these tumors are benign and are called adenomas. Cancers of the adrenal cortex are rare. These 2 types of tumors can sometimes be hard to tell apart when the cells are looked at under the microscope. Although experienced pathologists (doctors that are trained to look at tissue under the microscope) can tell the difference in most cases, sometimes the only way to know for sure that the tumor is a cancer is when it has spread. If it has spread to lymph nodes or.