Cushing's Syndrome and Disease

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Introduction

Cushing's syndrome refers to any situation of excess cortisol. Cushing's disease refers specifically to a pituitary tumour secreting ACTH.

 

The Case of...

a simple case introducing clincial presentation and calling for a differential diagnosis to get students thinking.

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Causes and Risk Factors

 

ACTH independent causes include:

ACTH dependent causes include:

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Pathophysiology

 

Adrenal tumours can be treated with surgery.

Pituitary adenomas can be cured much of the time.

ectopic sources of ACTH can be surgically removed if possible.

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Signs and Symptoms

Cushing's should be considered if people have:

 

appearance

skin

musculoskeletal

cardiovascular

metabolic

 

gonadal dysfunction

 

other

mental health changes

  • history
  • physical exam

History

 

Physical Exam

 

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Investigations

  • lab investigations
  • diagnostic imaging

Lab Investigations

Cortisol excess can be demonstrated by:

  • 24 hour urine free cortisol (4x normal cortisol levels is diagnostic, though false +ves and -ves)
  • low dose dex suppression test
    • demonstrates resistance to suppression
    • better sensitivity, but lower specificity
  • diurnal cortisol rhythm

There are some things about false positive tests I don't know.

Diagnostic Imaging

 

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Differential Diagnosis

pseudo-cushing's syndrome can result from mild physiologic hypercortisolism:

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Treatments

 

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Consequences and Course

 

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Resources and References

 

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Topic Development

authors:

reviewers:

 

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