In this image, you can see some of the
clinical findings we discussed.
On the left, we see her face,
which is moon shaped.
She has evidence of hirsutism
on her chin and on her cheeks.
On the image on the right,
we see these reddish stretch marks
in her lower abdomen,
otherwise known as livid striae.
Striae are very specific,
especially when they’re red,
for the presence of Cushing syndrome.
What they signify is that
the skin of the abdomen is stretching very rapidly,
mostly related to the centripetal
or central redistribution of fat
in the abdomen
causing the abdomen to distend acutely.
When this happens,
the skin stretches,
and as a consequence,
stretch marks appear.
The red color is from damage to
the capillaries as they expand
rapidly producing the classic
red or livid color.
Let's go through some of the classic
findings in Cushing syndrome.
First of all, patients may present
with weight gain,
slow healing of cuts,
an increase in the risk of infections,
as well as glucose intolerance.
Psychological conditions that may
accompany Cushing syndrome
include depression, anxiety, irritability,
loss of emotional control,
and cognitive difficulties,
and reduced libido.
As we saw in the prior image,
a moon face may appear
because of fat deposition
around the face.
They may also
The stem of the prior question talked about
fat redistribution in the neck.
This is commonly called
a buffalo hump.
Muscle weakness is a feature
as well of the condition
because of excess of cortisol.
In the skin, likewise,
there is thinning, fragility.
There is the presence
of acne on the face,
and excessive hairiness
otherwise known as hirsutism.
We've already addressed
the striae and their etiology.
In terms of vascular conditions
associated with Cushing syndrome,
new or worsening of blood pressure
is often noted.
The bones had also
increased risk for fractures
because of cortisol-mediated
The reproductive system
can also be affected,
in which case,
irregular or absent menstrual periods
may manifest in females,
and erectile dysfunction in males.
It's important to
differentiate Cushing disease
on the one hand
from Cushing syndrome.
Crushing disease, which is pituitary in origin,
is ACTH dependent
where the ACTH causes
excess cortisol production.
Cushing syndrome, on the other hand,
and ACTH is not responsible
for excess cortisol production,
as in the case we just saw
where the patient's ACTH level
was below five picograms per ml.
So, the patient in the prior example
had Cushing syndrome
as opposed to Cushing disease.
Excess cortisol production
due to ACTH-secreting pituitary adenomas.
Cushing disease is associated with
such as diabetes, morbid obesity,
Clinical features of Cushing syndrome
include specific findings,
less specific findings,
and associated findings.
Starting with the specific findings,
which is redness of the face,
supraclavicular fat pads,
dorsocervical fat pads,
and these wide violaceous
or livid striae
are pretty specific
for the condition.
Some less specific findings
from cortisol excess
include easy bruising,
excessive skin fragility,
proximal muscle weakness,
temporal balding, hirsutism
or abnormal hair growth in women,
and finally, menstrual abnormalities.
Associated conditions with
the Cushing syndrome
hypertension, diabetes mellitus,
the presence of obesity, depression,
such as hypokalemia, nephrolithiasis
which are kidney stones,
and the increased propensity
and pulmonary embolus.
Confirming the diagnosis of
Dexamethasone is administered at 11 PM
and cortisol is tested at 8 AM.
A pituitary source of ACTH
will respond to negative feedback
from high doses of dexamethasone
to less than
five micrograms per deciliter.
Ectopic sources of ACTH
do not have suppression of cortisol.
This test has a relatively
and a specificity of only 57%
for Cushing disease.
Here is an algorithm
that will help you confirm
the diagnosis of Cushing syndrome.
We always start clinically
where we suspect Cushing syndrome
based on our history
and physical exam.
The next step is
to exclude that the patient is not taking
exogenous glucocorticoids for some reason
such as for severe asthma
or in cases of intraarticular injections
for joint pain.
Once this is excluded,
perform initial lab testing
with a 24-hour urine
a one milligram dexamethasone
and a late night
salivary cortisol level.
If these are abnormal,
it is important to exclude
the presence of
Once physiological hypercortisolism
no further testing
needs to be done.
If, however, physiological hypercortisolism
then additional testing
should be performed,
and this may take the form
of additional imaging.
If these are abnormal,
then we confirm Cushing syndrome.
If the additional testing is normal,
repetition of the initial abnormal tests
is indicated to rule out
spurious positive results.
Alternatively, going back to
the top of the algorithm,
if the initial testing is all normal,
Cushing syndrome is very unlikely.
Once ACTH-dependent Cushing syndrome
is confirmed by chemically,
a pituitary MRI
should be obtained.
If no pituitary tumor or a tumor
less than six millimeters is visualized,
an MRI and an eight milligram
dexamethasone suppression test is used
to differentiate Cushing disease
from an ectopic source of ACTH.
This is the so-called
high-dose dexamethasone suppression test.
Ectopic ACTH production
from a non pituitary tumor
most often in the lung, pancreas,
or thymus is still very uncommon.
Going through the treatment
of Cushing disease.
Transsphenoidal pituitary tumor resection
is probably the most curative plan.
of endogenous ACTH production
in the remaining
normal pituitary gland
which will be suppressed
after the removal of the tumor
due to long-standing hypercortisolism,
and that may require
additional glucocorticoid replacement.
It may take up to one year
for endogenous ACTH production
to return to normal,
and sometimes the hypothalamic-pituitary-adrenal axis
does not recover.
If surgical cure is not achieved,
pituitary radiation may be required.
Medical therapy requires the inhibitors
of adrenal enzyme synthesis
of cortisol like
ketoconazole or metyrapone.
Dopamine agonists like
cabergoline may be used
and somatostatin analogues
Medical cure of Cushing disease
has a relatively low success rate.
But hypercortisolism symptom control
is an achievable goal
in all patients with
endogenous Cushing syndrome.