While doing your rounds, you see two individuals. First is Jessica, who comes in with lumbar pain, anuria, and constipation. Examination is unremarkable and she doesn’t have any history of kidney disease. The other person is 38-year-old Dan, who is obese and has an abnormally round face. He is also hypertensive and hyperglycemic. Dan is not taking any medications but he’s complaining of severe lumbar pain on the left side. Abdominal CT scans were obtained for both. In Jessica’s case, imaging detected a mass in the right adrenal cortex. In Dan’s case, CT detected a mass in the left adrenal cortex.
Ok, so both seem to have some type of adrenal masses. But first, a little bit of physiology. Each adrenal gland has two main components: the cortex and the medulla. For your exam, something high-yield to keep in mind is that the cortex is composed of 3 zones. The zona glomerulosa, the outer zone, contains clustered cells that produce mineralocorticoids, mainly aldosterone, which regulates blood pressure and electrolyte balance. The zona fasciculata, the middle zone, contains foamy-looking cells in columns that are responsible for the production of glucocorticoids, predominantly cortisol, which increases blood sugar levels via gluconeogenesis, suppresses the immune system, and aids in metabolism. And the innermost zone is the zona reticularis, which has basophilic cells arranged in anastomosing cords that produce gonadocorticoids, especially androgens like dehydroepiandrosterone or DHEA.
The medulla is composed of special cells called chromaffin cells. These are modified postganglionic sympathetic neurons that originate from the neural crest. Normally, when a fetus is in its 5th week of development, special cells called neural crest cells start migrating along the midline of the embryo. In the thoracic region, neural crest cells differentiate into the neurons of the sympathetic chain on either side of the developing spinal cord. In the lumbar region, neural crest cells differentiate into the cells of the adrenal medulla.
