Download MEDICAL MYSTERY FOR CHAPTER 13

MEDICAL MYSTERY FOR CHAPTER 13
HER STORY
All her life, Barbara had been thin. But a year after giving birth to her second child,
she started gaining weight rapidly. At first, she blamed it on her pregnancy, which
had resulted in 35 unwanted pounds. But even when she cut back her calorie intake
and started going to a gym 4 days a week, the weight piled on. At times, especially
at night, she started feeling wired and had trouble falling asleep. She also noticed
purplish stretch marks on her abdomen and thighs, which she blamed on the
pregnancy. Her doctor had advised Barbara to lose weight. But the scale wouldn’t
budge.
Recently, she started feeling so fatigued that she couldn’t get out of bed. She had
lost her sex drive completely. Overwhelmed, Barbara began to feel depressed and
anxious, especially when she noticed hair growth on her chin. In addition, her skin
was blotchy and red and prone to bruise easily. One day, when her toddler grabbed
her arm, Barbara noticed purplish bruises shaped like her child’s fingerprints. That’s
when she decided to go back to her doctor.
The first thing the doctor detected was hypertension. He also measured Barbara’s
levels of thyroid stimulating hormone (TSH), a hormone that increases in people
who have hypothyroidism. The results, however, were normal. After Barbara
described her failed weight-loss efforts, her physician referred her to our group,
suspecting endocrinopathy.
THE EVALUATION
When I first saw Barbara, we had a long discussion about her recent battles with
weight. I noticed that her weight was concentrated in her abdomen and that her arms
and legs remained lean. In addition, Barbara had a “buffalo hump” on her upper back
and a round face. She had trouble standing up from a squat.
Between the physical exam and Barbara’s medical history, I began to suspect that
Barbara had Cushing’s syndrome, a condition that occurs when the body is exposed
to high levels of the hormone cortisol for long periods of time. The condition is also
called hypercortisolism. It is more common in women than men and tends to occur
between the ages of 20 and 50. The telltale signs are rapid and inexplicable onset of
obesity, menstrual irregularities, acne, facial hair, trouble sleeping, and onset of
depression.
THE DIAGNOSIS
To determine whether Barbara had Cushing’s syndrome, I had ordered three 24-hour
urine tests, each of which involved collecting urine for an entire day. Her first test
showed normal cortisol levels at 38 g/day. But her second and third cortisol levels
came in at slightly above the 50 g/day, consistent with Cushing’s syndrome. Other
blood, saliva, and urine tests also showed elevated cortisol levels. I needed to
determine what was causing the excess cortisol. In some cases, Cushing’s can occur
from long-term exposure to glucocorticoid hormones for medical conditions such as
lupus, rheumatoid arthritis, or asthma. But since Barbara had none of these
conditions and was not on any medications, I suspected she had a tumor on either
her pituitary or adrenal glands.
To find out for sure, I did a blood test measuring the hormone adrenocorticotropin
(ACTH). It was slightly elevated, consistent with a pituitary tumor. If it was low, it
would have meant she had an adrenal tumor. I then ordered a high-resolution
dynamic MRI, which showed a small tumor on her pituitary.
Pituitary tumors are the most common cause of Cushing’s syndrome and affect
women five times more frequently than men. The tumor—usually, there is just one—
is benign but does cause the pituitary gland to secrete too much ACTH, the hormone
that stimulates the production of cortisol by the adrenal glands.
THE TREATMENT
Relieving Barbara of Cushing’s meant surgically removing the tumor in a procedure
called transsphenoidal adenomectomy. The procedure is extremely delicate and
involves reaching the pituitary gland through a nostril or an opening above the upper
lip. More than 80% of all patients have success with this procedure, and Barbara was
no exception.
After the surgery, Barbara’s body immediately produced lower than normal levels
of ACTH, which also reduced her cortisol levels. This was entirely expected as part
of the treatment. To compensate for this temporary reduction, I gave Barbara
hydrocortisone, which is a synthetic form of cortisol. I told her she would probably
be able to stop taking this within a year.
CASE CLOSED
When I saw Barbara again 2 months later, she had dropped 10 pounds. Her blood
pressure had stabilized, the stretch marks had vanished, and she was feeling much
happier and less tired. She wanted to know when she’d lose the rest of the extra
weight, and I advised her to be patient. I also told her to eat normal-sized portions
of healthy foods and to try walking to build up her strength and energy. The
combination, I assured her, would help her slim back down again as she recovered
from her bout with Cushing’s.
Discussion Questions
1. Why might Barbara’s doctor suspect hypothyroidism? Why was that not
accurate?
2. Where are the adrenal glands located, and what do the adrenal glands do?
3. Barbara’s body had an excess of cortisol. What is the function of cortisol?
4. Use your knowledge of word parts to define a transsphenoidal adenomectomy.