Masses on the adrenal glands form when cells mutate or overgrow from environmental stimulation or genetic factors. Adrenal masses can be cancerous or non-cancerous, also referred to as malignant or benign. Cancerous masses can spread to other parts of the body, but a benign mass does not spread. Cancerous adrenal masses, or tumors, may start in the adrenal gland itself. This type of adrenal tumor is called a primary adrenal tumor.
Adrenal tumors can also occur in secondary form, beginning in or on another organ and then spreading to the adrenal glands. An adrenal gland tumor, whether malignant or benign, can cause the overproduction of hormones. These types of adrenal tumors are called functioning tumors. Tumors on the adrenal gland that do not cause hormone fluctuation are called non-functioning tumors. Symptoms and treatment of adrenal gland tumors vary based on the type of tumor, what hormones are potentially affected and whether or not the tumor is primary or secondary.
Types of primary adrenal gland tumors include adenomas, which are non-cancerous and non-functioning but are the most common type of adrenal tumor. Adenomas rarely cause symptoms and are sometimes small enough to not require treatment.
The most common type of cancerous adrenal tumor is adrenocortical carcinoma. Adrenocortical carcinomas can be functioning or non-functioning. Functioning adrenocortical carcinomas can produce more than one hormone and cause fluctuations of more than one hormone.