Question: Three years ago, I had an adrenal gland removed due to an adrenal adenoma that was causing Cushing's. Now, I am told that I have another tumor on my right adrenal gland. Is this possible, and what is the best way to tell if it is secreting cortisol?

Answer: Removal of a solitary adrenal gland is often followed by a compensatory enlargement of the other (and presumably normal) adrenal gland. This phenomenon occurs in a normal fashion and is poorly understood and not often well appreciated. Occasionally, this enlargement can appear to represent an adrenal tumor. Assuming that you had a cortisol producing adrenal adenoma removed three years ago, it is very unlikely (and to my knowledge unheard of) that you would develop a similar tumor in the right adrenal gland. I have had a patient who developed a cortisol producing adrenal tumor several years after the other adrenal gland had been removed during surgery for kidney cancer. The best way to determine if your "tumor" in the right adrenal is secreting cortisol is to measure plasma ACTH levels and annual assessment of urinary free cortisol. If the plasma ACTH level is below normal or the 24 hour urine free cortisol is above normal, additional treatment may be necessary.