Endocrinology

Missed Concepts

• Workup of thyroid nodule almost always ends with FNA, the one exception is a patient without suspicious US findings or cancer risk factors, a low TSH, and a hot nodule on 123-Iodine scan (toxic adenoma). For these patients go straight to treatment (Methimazole pretreatment to achieve euthyroid > RF ablation vs. surgery)
• Hashimoto thyroiditis can be associated with other autoimmune conditions such as atrophic gastritis (pernicious anemia).
• During vitamin B12 repletion, you should monitor serum potassium, which can drop as new RBCs are formed.
• Young, normal weight patient, without family history of diabetes presents with symptomatic DKA? T1DM
• Total T3 and T4 in pregnancy can be 1.5x normal range and still be physiologic. TSH is suppressed. There is no role for measuring free T4 in pregnancy
• Hyperglycemia and catabolic symptoms (weight loss, urinary frequency) are indications for insulin.
• One complication of SGLT2 inhibitors is euglycemic DKA with BG < 250, but still with an elevated AG and low pH.
• Prolactin-secreting pituitary adenomas, including large ones, are first treated with oral dopamine antagonists, whereas other pituitary adenomas are treated with surgery if large enough.

Electrolyte Imbalanaces

Symptoms of Electrolyte Disturbances

Electrolyte	High	Low
Sodium	Example	Example
Potassium	Example	Example
Calcium	Example	Increased DTRs
Magnesium	Low-absent DTRs	Example
Phosphorus	Example	Example

Hyponatremia

• Moderate to severe hypothyroidism can cause cause mild euvolemic hyponatremia.

Hypercalcemia

• H&P:
• Dx: Best initial test is PTH
• Tx: