Two new cases of Cushing’s syndrome in the same afternoon: Part 1

Yesterday, my first patient in the afternoon was a 27-year-old woman with weight gain and fatigue. She had primary hypothyroidism, but her thyroid-stimulating hormone was 1.57, and free thyroxine and free triiodothyronine were in the mid-normal range. Her primary care physician told her she did not think her symptoms were related to her thyroid but requested she see me anyway. Her physician was concerned there may be something else going on that was being missed.

Most referrals I see with weight gain and fatigue do not have endocrine disease. Many others have untreated or under-treated hypothyroidism which can be addressed with initiation or increase of thyroid hormone therapy. Of every 100 patients sent to me to rule out possible Cushing’s syndrome, I may identify only one or two. I have gone six months or longer without seeing any new cases.

At first glance, this young woman did not appear abnormal. She was not obese, weighed only 155 lb. There was no rounded face or abnormal striae. In the past, another doctor (not the one who sent her to me) had told her, “You need to exercise harder and cut your calories more or get used to it.”

I had gone into the room prepared to tactfully and kindly explain the effects of diet and lifestyle on weight and energy levels. However, her 22-lb weight gain occurred rather suddenly, even despite training for a triathlon. Although some slight gain in weight due to increased muscle mass due to training may be normal, the amount she had gained while training heavily did not make sense to me. Instead of increased muscle mass, she had decreased muscle strength and endurance.

What was most striking were some of her laboratory studies. An a.m. cortisol was 38.1 (upper limits of normal, 25), and adrenocorticotropic hormone was undetectable. She has not taken any exogenous glucocorticoids or nutritional supplements for “adrenal support.” Although random a.m. cortisol and ACTH may not be absolutely diagnostic for Cushing’s syndrome, these initial results were highly suspicious. I ordered screening studies including midnight salivary cortisol, dexamethasone suppression study and 24-hour urine-free cortisol. I will be highly surprised if they come back negative.

Cushing’s syndrome is uncommon. Nevertheless, that does not keep me from searching. Long ago, I learned to not make a decision as to whether someone has subclinical Cushing’s syndrome or not based on clinical features alone. However, for those who have the disease and remain undiagnosed, finding it can be life altering.

I looked at my schedule and saw that my last patient of the day was coming to see me for weight gain, fatigue and to “rule out possible Cushing’s.”

“What are the chances of me seeing two new cases in one day?” I thought. “Not very likely.”

-To be continued-