Cushing’s Syndrome
Stephen Ou R2
May 17, 2013
Learning Objectives
•
Discuss the different etiologies of hypercortisolism.
•
Recognize the clinical manifestations of Cushing’s syndrome
•
Understand the screening tests for Cushing's syndrome
•
Establishing the cause of Cushing’s Syndrome.
Definitions
• Cushing’s syndrome: constellation of
symptoms associated with cortisol excess.
• Cushing’s disease: Cushing’s Syndrome due to
pituitary ACTH hypersecretion.
Clinical Manifestations
Most Specific
- Spontaneous
Bruising
- Proximal
Myopathy
Nonspecific
- Central obesity w/
extremity wasting
- Dorsocervical fat
pads (“Buffalo
Hump”
- Abdominal striae
- Round facies
(“Moon Facies”)
- DM
- Depression
- HTN
- Insomnia
- Obesity
- Psychosis
- Oligomenorrhea
- Impaired Cognition
- Osteoporosis
- Hirsutism
- Fungal Skin
Infections
- Nephrolithiasis
- Polyuria
Clinical Manifestations
of Cushing’s Syndrome
Facial Plethora i.e. “Moon Facies”
Dorsocervical fat pad i.e. “buffalo hump”
It’s not always Cushing’s
• Other common conditions associated with high cortisol
levels
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–
–
–
–
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Pregnancy
Etoh dependence
Morbid Obesity
Depression
Poorly controlled Diabetes
Physical stress/Malnutrition/Chronic Exercise
• Bottom line: There are many other causes of
hypercortisolism (Best to test in the outpatient setting)
Diagnosis of Cushing’s Syndrome
• Obtain a careful history to exclude exogenous
glucocorticoid use.
• Perform at least two first-line biochemical tests
to obtain the diagnosis:
– Urine free cortisol (UFC) (at least two measurements)
– Late-night salivary cortisol (two measurements)
– 1-mg overnight Dexamethasone Suppression Test
(DST)
– Longer low-dose Dexamethasone Suppression Test
(LDDST) (2 mg/d for 48 h)
Algorithm for testing
Case Vignette
A 67 year old woman is evaluated weight gain, hypertension and T2DM
over the last 2 years. She has also developed muscle weakness of the
lower extremities over the last 6 months. Physical exam is notable for a
BP of 154/92, facial hirsutism, obesity, abdominal striae, proximal
weakness and peripheral edema. Laboratory studies notable for
potassium of 2.9 meq/L. Which of the following diagnostic tests should
be performed next?
A.
B.
C.
D.
E.
Adrenal CT
C- peptide measurement
Glutamic acid decarboxylase antibody titer
Pancreatic MRI
24-hour urine free cortisol excretion.
Case Vignette
A 67 year old woman is evaluated for a 2-day history of severe muscle
weakness of the bilateral upper extremities. She has also experienced
significant weight gain, developed hypertension and T2DM over the last 2
years. She also developed muscle weakness of the lower extremities 6
months ago. Physical exam is notable for a BP of 154/92, facial hirsutism,
central obesity, abdominal striae, proximal weakness and peripheral
edema. Laboratory studies notable for potassium of 2.9 meq/L. Which of
the following diagnostic tests should be performed next?
A.
B.
C.
D.
E.
Adrenal CT
Hemoglobin A1c
Glutamic acid decarboxylase antibody titer
Pancreatic MRI
24-hour urine free cortisol excretion.
Take Home Points
•
There are a number of different causes of hypercortisolism including
Cushing’s Syndrome
•
The clinical manifestations of cushing’s syndrome vary in specificity
•
Diagnosing Cushing’s syndrome includes the use of at least two first
line biochemical tests.
References
• UpToDate: sections on cushing’s syndrome
– Epidemiology and clinical manifestations of Cushing’s syndrome
– Establishing the diagnosis of Cushing’s syndrome
– Establishing the cause of Cushing’s Syndrome
• The Diagnosis of Cushing’s Syndrome: An Endocrine Society
Practice Guideline. JCEM 2008 May; 93(5): 1526-1540.
• Pocket Medicine: Cushing’s Syndrome