Updated: 1/5/2021

Cushing Syndrome

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
5 5
0
0
0%
0%
Evidence
4 4
0
0
Snapshot
  •  A 42-year-old obese woman who does not smoke presents with diastolic hypertension and menstrual irregularities. Physical exam shows a full, plethoric-appearing face, increased facial hair, truncal obesity, and purple striae around the abdomen. Scattered echymoses are present over the entire body. Labs show a Hgb of 18 g/dL and a WBC of 18,000/mm^3. The leukocyte differential shows an absolute neutrophillic leukocytosis. CXR is normal.
Introduction
  • A condition that refers to the manifestations of hypercortisolism
    • results in hyperplasia of the adrenal cortex
      • specifically the fasiculata
  • There are several types
    • iatrogenic Cushing's
      • patients taking steroids is the most common cause of Cushing's syndrome
    • pituitary adenoma (Cushing's disease)
      • most common pathogenic cause (70%)
      • majority of adenomas are benign
      • cause bilateral hyperplasia of the adrenal glands
        • associated increase in conversion of norepinephrine to epinephrine in medulla 
          • enzyme involved is phenylethanolamine n-methyltransferase
    • adrenal Cushing's 
      • adenoma of the adrenals
    • ectopic Cushing's
      • ectopic ACTH secretion
      • extremely high ACTH
      • most commonly from small cell carcinoma of the lung
        • less commonly thymic cancer
Presentation
  • Symptoms
    • depression and psychological changes
    • oligomenorrhea
    • growth retardation
    • weakness
      • catabolism of muscle for gluconeogenesis
    • symptoms of diabetes (polydipsia, polyuria, and dysuria)
  • Physical exam
    • diastolic hypertension
    • central obesity
    • muscle wasting
    • thin skin that easily bruises/purple abdominal striae
      • due to weakening of collagen
    • hirsutism
    • moon facies
    • buffalo hump
Evaluation
  • Labs
    • hyperglycemia
      • cortisol is gluconeogenic
    • hypokalemia
      • at high concentrations cortisol can have partial activity at the aldosterone receptor
    • screen for 24-hour free urinary cortisol as well as a serum cortisol level
      • high positive and negative predictive value
    • serum ACTH to localize lesion  
      • iatrogenic
        • ↓ ACTH
      • pituitary
        • ↑ ACTH
      • adrenal
        • ↓ ACTH
      • ectopic
        • ↑ ACTH
    • if ACTH is high, then use high dose dexamethasone suppression test 
      • pituitary
        • ↓ cortisol production (i.e. production is suppressible) 
      • ectopic
        • no change in cortisol (i.e. production is NOT suppressible)
 

Please rate topic.

Average 5.0 of 10 Ratings

Questions (5)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M1.EC.13.90) A 50-year-old female is evaluated by her physician for recent weight gain. Physical examination is notable for truncal obesity, wasting of her distal musculature and moon facies. In addition she complains of abnormal stretch marks that surround her abdomen. The physician suspects pituitary adenoma. Which of the following high-dose dexamethasone suppression test findings and baseline ACTH findings would support his view? Tested Concept

QID: 100391
1

Cortisol suppression, normal baseline ACTH

14%

(16/118)

2

Cortisol suppression, high baseline ACTH

41%

(48/118)

3

No cortisol suppression, high baseline ACTH

19%

(22/118)

4

No cortisol suppression, low baseline ACTH

8%

(9/118)

5

Elevation of cortisol above pre-test levels, high baseline ACTH

11%

(13/118)

M 2 E

Select Answer to see Preferred Response

(M1.EC.13.74) A 35-year-old Caucasian female presents to the hospital alarmed by her recent truncal weight gain, facial hair growth, and thinning skin. During the physical exam, the physician finds that the patient is hypertensive. Serum analysis reveals hyperglycemia. The physician suspects a pituitary adenoma. Which dexamethasone test result would help confirm the physician's suspicions? Tested Concept

QID: 100375
1

Low-dose, increased ACTH; high-dose, increased ACTH

6%

(2/34)

2

Low-dose, increased ACTH; high-dose, decreased ACTH

12%

(4/34)

3

Low-dose, decrease in ACTH; high-dose, no change in ACTH

3%

(1/34)

4

Low-dose, no change in ACTH; high-dose, no change in ACTH

15%

(5/34)

5

Low-dose, no change in ACTH; high-dose, decreased ACTH

65%

(22/34)

M 2 E

Select Answer to see Preferred Response

(M1.EC.13.96) A 34-year-old Caucasian female presents with truncal obesity, a rounded "moon face", and a "buffalo hump". Serum analysis shows hyperglycemia. It is determined that a pituitary adenoma is the cause of these symptoms. Adrenal examination is expected to show? Tested Concept

QID: 100397
1

Atrophy of the adrenal cortex

0%

(0/25)

2

Diffuse hyperplasia of the adrenal cortex

96%

(24/25)

3

Atrophy of the adrenal medulla

0%

(0/25)

4

Adrenal adenoma

4%

(1/25)

5

Atrophy of the adrenal gland

0%

(0/25)

M 1 E

Select Answer to see Preferred Response

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Evidence (4)
Topic COMMENTS (21)
Private Note