questions 3

Cushing Syndrome

Topic updated on 10/20/16 5:20pm

  •  A 42-year-old obese women 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 stria around the abdomen. Scattered echymosis is present over the entire body. Labs show an HgB of 18 g/dL and a WBC of 18,000. The leukocyte differential shows an absolute neutrophillic leukocytosis. CXR is normal.
  • 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 disease
    • pituitary adenoma (Cushing's disease)
      • most common pathogenic cause (70%)
      • majority of adenomas are benign
    • 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
  • 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
  • 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)


Qbank (3 Questions)

(M1.EC.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? Topic Review Topic

1. Low-dose, increased ACTH; high-dose, increased ACTH
2. Low-dose, increased ACTH; high-dose, decreased ACTH
3. Low-dose, decrease in ACTH; high-dose, no change in ACTH
4. Low-dose, no change in ACTH; high-dose, no change in ACTH
5. Low-dose, no change in ACTH; high-dose, decreased ACTH

(M1.EC.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? Topic Review Topic
FIGURES: A          

1. Cortisol suppression, normal baseline ACTH
2. Cortisol suppression, high baseline ACTH
3. No cortisol suppression, high baseline ACTH
4. No cortisol suppression, low baseline ACTH
5. Elevation of cortisol above pre-test levels, high baseline ACTH

(M1.EC.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? Topic Review Topic

1. Atrophy of the adrenal cortex
2. Diffuse hyperplasia of the adrenal cortex
3. Atrophy of the adrenal medulla
4. Adrenal adenoma
5. Atrophy of the adrenal gland


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