Endocrinology

Question 1

The first step in the diagnosis of gigantism

Answer 1

Confirm elevated levels of IGF-1.
The next step is to perform an oral glucose suppression test to see if growth hormone remains elevated despite oral glucose. Normally, growth hormone decreases with elevated glucose.
Finally, MRI can be performed to look for a pituitary lesion.

Question 2

Adrenal insufficiency

Answer 2

Addison disease or autoimmune adrenalitis
Elevated plasma ACTH
Decreased aldosterone
possible hyponatremia
hyperkalemia
hypoglycemia
metabolic acidosis.
Clinical manifestations: skin hyperpigmentation, nausea/vomiting, fatigue, weight loss, orthostatic hypotension, fatigue, and myalgias/arthralgias.
Cosyntropin stimulation test may confirm the diagnosis of adrenal insufficiency.
Patients will often need lifelong glucocorticoid and mineralocorticoid replacement.

Question 3

Clinical symptoms associated with hypercalcemia

Answer 3

Bones (fractures and pain)
Stones (nephrolithiasis)/ Diabetes insipidus (Dehydrated patient but increase Urinary output)
Groans (vomiting and constipation)
Psychic overtones (altered mental status).

Question 4

Grave’s disease occurs due to?

Answer 4

Thyroid stimulating immunoglobulins (TSI’s) binding to TSH receptors causing excess thyroid hormone release.

Question 5

Subacute granulomatous thyroiditis

Answer 5

Also called de Quervain thyroiditis
The most common cause of thyroid pain The etiology is often post-infectious and viral in origin.
Early in the course of the disease, the patient may be hyperthyroid as follicular cells are damaged and release large amounts of T3/T4. This is often followed by a period of hypothyroidism as T3/T4 is depleted, and eventually euthyroidism within the oncoming months.
Enlarged and tender thyroid gland. Treatment is only NSAIDs and symptom control since this condition resolves on its own.

Question 6

Lithium and thyroid hormone

Answer 6

Lithium normally suppresses thyroid hormone production, causing hypothyroidism, but rare cases of lithium-associated thyrotoxicosis have been described.

Question 7

Which enzyme requires folate and Vit B12 as cofactors?

Answer 7

Methionine synthase

Question 8

Vitamin D deficiency, Calcium, phosphate, PTH and Alkaline phosphatase alterations?

Answer 8

Decreased calcium, phosphorus, and cholecalciferol and an increased alkaline phosphatase and PTH.

Question 9

Idiopathic central precocious puberty treatment

Answer 9

GnRH agonists to suppress hypothalamic-pituitary axis (Leuprolide)

Question 10

Elevated urinary and serum cortisol levels that do not decrease despite dexamethasone in the setting of low ACTH indicates?

Answer 10

A primary adrenal process.

Question 11

Test to confirm osteomalacia?

Answer 11

Best test to confirm the diagnosis is 25-hydroxyvitamin D.
1,25-Hydroxyvitamin D is the active form of vitamin D found in the human body. Its levels fluctuate with levels of parathyroid hormone and calcitonin therefore it is not the best representation of the patient’s vitamin D stores.

Question 12

Pregnancy and thyroid hormones

Answer 12

Beta-hCG has a similar structure to TSH: increases the concentration of thyroxine in the body slightly.
Estrogen leads to an increase in the production of thyroid-binding globulin so that the total level of T4 dramatically increases more than the level of free thyroxine.
Free T4 increase creates a negative feedback that decreases the level of TSH. This becomes the new equilibrium during the pregnancy.
Since the level of free T4 is only slightly increased, a pregnant patient is clinically euthyroid and does not present with symptoms of hyperthyroidism.