Physiology

Question:

A 36-year-old woman dies from an acute adrenal crisis following a surgical procedure. A pituitary tumor was diagnosed 3 weeks ago. At autopsy, the adrenal glands are small, and the cortex is composed primarily of cells from the zona glomerulosa. Which of the following best explains the decreased size of the cortex?

Correct Answer: B.  Decreased ACTH concentration

(B) In the adrenal gland, the zona glomerulosa produces mineralocorticoids, the zona fasciculata produces glucocorticoids, and the zona reticularis produces androgens. This patient’s pituitary tumor was likely causing compression/destruction of ACTH-secreting cells as well as LH/FSH-secreting cells of the pituitary. This caused atrophy of the zona fasciculata and zona reticularis, respectively. The zona glomerulosa, which responds primarily to angiotensin II and serum potassium levels were spared. An acute stressor, such as this woman’s surgery, will increase the body’s need for cortisol and can lead to acute adrenal crisis in a case such as this.

We are not given any information that would lead us to believe there was autoimmune destruction, denervation, or granulomatous disease. This woman’s cortisol deficiency was likely a cause of the tumor in her pituitary rather than a primary adrenal deficiency.