Free practice quiz
ABIM Endocrinology Prep Course (Endo): free quiz
10 questions from the program. See your score right away, then unlock the explanation of every answer.
- Question 1 of 10
A 46-year-old man with obesity is seen for fatigue and diabetes screening. He takes no glucocorticoids and has no known anemia, kidney disease, or hemoglobinopathy. BMI is 33 kg/m2. Fasting plasma glucose is 128 mg/dL and hemoglobin A1c is 6.4%. One week later, repeat fasting plasma glucose is 131 mg/dL and A1c is 6.3%. He has no polyuria, polydipsia, or weight loss. What is the best interpretation?
Diabetes diagnostic thresholds
Diabetes is diagnosed by fasting plasma glucose ≥126 mg/dL, A1c ≥6.5%, 2-hour OGTT glucose ≥200 mg/dL, or random glucose ≥200 mg/dL with symptoms. Without unequivocal hyperglycemia, repeat abnormal testing is required; this patient has two diabetic-range fasting glucose values. A is wrong because symptoms are not required when laboratory confirmation is present. C is tempting because A1c is in the prediabetes range, but the confirmed fasting glucose criterion establishes diabetes. D is wrong because random glucose with symptoms is only one diagnostic pathway.
Diagnose diabetes; order baseline complication and cardiovascular risk assessment; treat with lifestyle plus individualized pharmacotherapy; escalate urgently only for symptomatic severe hyperglycemia or ketosis. - Question 2 of 10
A 63-year-old man with type 2 diabetes and established cardiovascular disease presents for treatment planning. His current glycemic measurements are moderately above his individualized goal, and further glucose lowering may require additional medication and monitoring. Which principle should guide selection of his treatment goal and overall diabetes management strategy?
A. Incorrect. Cardiovascular comorbidity is a relevant factor in individualized diabetes management and should not be excluded from treatment planning.
B. Correct. Glycemic targets should be selected within the broader context of cardiovascular health, anticipated microvascular benefit, hypoglycemia risk, and treatment burden. This approach avoids focusing on glucose measurements in isolation.
C. Incorrect. Established cardiovascular disease does not independently mandate the most stringent possible glycemic goal. Treatment safety and individual circumstances remain important.
D. Incorrect. Cardiovascular disease changes the context of individualized diabetes care but does not eliminate the importance of setting an appropriate glycemic goal.
- Question 3 of 10
A 29-year-old man with insulin-treated diabetes is found to have repeated low glucose measurements without his usual warning symptoms. He previously recognized hypoglycemia promptly, but recently he has required assistance from coworkers on two occasions. His endocrinologist identifies hypoglycemia unawareness. Which management approach is most appropriate to help reduce the risk of future severe episodes and potentially improve symptom awareness?
A: Incorrect. Continued exposure to hypoglycemia may perpetuate impaired awareness and increases the risk of severe episodes. Prevention focuses on reducing recurrent low glucose rather than deliberately tolerating it.
B: Incorrect. Reliance on symptoms is especially unsafe when symptom awareness is impaired. The current pattern requires reassessment of insulin treatment and increased attention to objective glucose measurements.
C: Correct. Avoiding recurrent hypoglycemia is central to managing hypoglycemia unawareness and may help restore warning symptom recognition. Regimen adjustment, individualized glycemic goals, and appropriate glucose monitoring support safer management and prevention of severe episodes.
D: Incorrect. The absence of warning symptoms does not mean low glucose concentrations are harmless. Monitoring is particularly important when the patient cannot reliably recognize hypoglycemia.
- Question 4 of 10
A 63-year-old woman receiving high-dose dexamethasone for an inflammatory disorder develops a mildly suppressed TSH concentration during hospitalization. Her free T4 remains within the reference interval, and thyroid testing obtained before glucocorticoid therapy was normal. She has no new clinical features suggesting thyrotoxicosis. Which mechanism most likely contributes to the change in TSH?
A. Incorrect. Increased thyroxine-binding globulin primarily affects total thyroid hormone concentrations. It does not explain the characteristic TSH-suppressive effect associated with high-dose glucocorticoid administration.
B. Incorrect. Glucocorticoids can alter thyroid physiology, particularly TSH secretion, but they do not invariably cause a falsely elevated free T4 through direct analytical interference. The patient's normal free T4 does not support this proposed mechanism.
C. Correct. High-dose glucocorticoids can suppress hypothalamic-pituitary regulation of TSH secretion, resulting in a reduced TSH concentration without primary thyroid hormone excess. Medication exposure, baseline thyroid tests, free hormone concentrations, and the clinical picture should be considered before diagnosing intrinsic thyroid disease.
D. Incorrect. A low TSH during glucocorticoid treatment does not by itself establish persistent primary hyperthyroidism. Drug-related changes in TSH secretion are important alternative explanations, especially when free T4 and the clinical examination are reassuring.
- Question 5 of 10
A 46-year-old woman presents with 6 months of fatigue, constipation, cold intolerance, and 5-kg weight gain. She has vitiligo and no history of neck irradiation, thyroid surgery, pregnancy in the past year, or lithium/amiodarone use. Examination shows dry skin, delayed relaxation of ankle reflexes, and a firm, nontender, diffusely enlarged thyroid. Labs show TSH 28 mIU/L, free T4 0.5 ng/dL, and markedly elevated anti-thyroid peroxidase antibodies. Which cause of primary hypothyroidism is most likely?
Autoimmune primary hypothyroidism
Hashimoto thyroiditis is lymphocytic autoimmune destruction of thyroid follicles; high TSH, low free T4, firm goiter, anti-TPO antibodies, and vitiligo identify it. D is tempting because iodine deficiency can cause goiter, but positive anti-TPO and autoimmune clustering discriminate. A usually follows recent pregnancy and often has a transient thyrotoxic phase. A is correct. A requires lithium exposure and does not best explain anti-TPO-associated disease.
Diagnose Hashimoto thyroiditis; order TSH/free T4 and anti-TPO when etiology is unclear; treat overt disease with levothyroxine; refer/escalate for nodules, compressive goiter, pregnancy, or unstable cardiac disease. - Question 6 of 10
A 68-year-old man has a 4.5-cm thyroid nodule that was previously sampled and classified as Bethesda II, benign. During the past several months, he has developed progressive difficulty swallowing solid foods and a sensation of pressure when lying flat. Repeat examination and imaging confirm that the nodule is producing local compressive effects. What is the most appropriate next step?
A: Incorrect. Benign cytology reduces concern for malignancy but does not exclude the need for treatment when a nodule causes clinically significant compressive symptoms.
B: Correct. Progressive dysphagia and positional pressure attributable to a thyroid nodule are important indications for surgical evaluation. Management depends on both cytologic risk and clinical effects, so symptomatic benign nodules may warrant surgery.
C: Incorrect. Molecular testing is not routinely indicated for Bethesda II cytology and would not address the mechanical compression producing the patient's symptoms.
D: Incorrect. Repeated aspiration without addressing progressive compression is inadequate. Symptom progression should prompt consideration of definitive treatment rather than an automatic surveillance-only approach.
- Question 7 of 10
A 46-year-old man with a pituitary macroprolactinoma is treated with cabergoline. Follow-up serum prolactin concentrations have decreased substantially, and his clinical symptoms are improving. His endocrinologist wants to evaluate the structural response of the sellar lesion to treatment. Which of the following is the most appropriate investigation?
A: Incorrect. Abdominal ultrasonography does not evaluate the sellar lesion and cannot determine the structural response of a pituitary macroprolactinoma.
B: Correct. Follow-up pituitary MRI is an important component of prolactinoma management, particularly when a macroadenoma is present. MRI evaluates changes in tumor size and mass effects, complementing serum prolactin measurements. The imaging interval should be selected according to the clinical context rather than inferred solely from biochemical improvement.
C: Incorrect. Electroencephalography assesses cerebral electrical activity, not the size or structural response of a pituitary tumor.
D: Incorrect. A decrease in prolactin is evidence of biochemical improvement but does not replace appropriate MRI surveillance of a known macroadenoma. Both hormonal and structural responses are relevant to management.
- Question 8 of 10
A 43-year-old woman presents with a 4-month history of urinary frequency, nocturia, and increased thirst. She reports urinating approximately 12 times daily but has never measured her urine volume. Her serum sodium is 140 mEq/L, and she has no history of pituitary disease or medication exposure associated with impaired urinary concentration.
Which of the following is the most appropriate next step in evaluating her symptoms?
A. Incorrect. Water deprivation testing evaluates the mechanism of established hypotonic polyuria. Urinary frequency alone does not establish increased total urine production, so formal assessment of the water-balance axis is premature.
B. Correct. The initial step in evaluating suspected polyuria-polydipsia syndrome is confirming that true polyuria exists. A 24-hour urine collection quantifies daily urine output and distinguishes increased urinary frequency from excessive urine production. Once polyuria is established, urine concentration can be evaluated to determine whether the urine is hypotonic before proceeding to diagnostic testing for diabetes insipidus or primary polydipsia.
C. Incorrect. Pituitary imaging may be appropriate after evidence suggests a central defect in water regulation. Imaging before confirming hypotonic polyuria is not the appropriate initial diagnostic step.
D. Incorrect. Desmopressin responsiveness can help distinguish central from nephrogenic diabetes insipidus, but administering it before confirming hypotonic polyuria is premature and may be unsafe if the patient has excessive voluntary water intake.
- Question 9 of 10
A 43-year-old woman presents with several months of fatigue, decreased appetite, and intermittent lightheadedness. Her serum cortisol concentration obtained at 8:00 AM is 8.2 mcg/dL, and she is not taking glucocorticoids. The endocrinologist considers the result indeterminate for adrenal insufficiency. Which of the following is the most appropriate next diagnostic step?
A — Correct: An intermediate morning cortisol concentration does not reliably confirm or exclude adrenal insufficiency. Cosyntropin stimulation testing evaluates adrenal cortisol reserve and is appropriate when the basal morning cortisol is indeterminate.
B — Incorrect: A detectable cortisol concentration does not establish adequate adrenal function. Intermediate morning values require further evaluation.
C — Incorrect: A single indeterminate cortisol concentration cannot establish primary adrenal insufficiency or distinguish primary from central causes. Additional dynamic testing and ACTH assessment are needed.
D — Incorrect: Random afternoon cortisol measurements are affected by normal diurnal variation and do not provide the standardized assessment of adrenal reserve obtained with cosyntropin stimulation.
- Question 10 of 10
A 52-year-old woman with confirmed endogenous Cushing syndrome has progressive proximal muscle weakness, hypertension, and worsening hyperglycemia. Definitive treatment is planned, but several weeks of medical stabilization are needed. The endocrinologist selects a medication specifically intended to reduce adrenal cortisol synthesis. Which therapeutic class best accomplishes this objective?
A: Correct. Steroidogenesis inhibitors reduce cortisol production and are an important medical treatment option for endogenous hypercortisolism. They can be used to control cortisol excess while definitive therapy is being arranged.
B: Incorrect. Glucocorticoid receptor antagonists oppose cortisol action at its receptor rather than directly inhibiting adrenal cortisol synthesis. They represent a different mechanism of medical treatment.
C: Incorrect. Managing hyperglycemia is important because cortisol excess causes metabolic complications, but glucose-directed treatment alone does not address excessive cortisol production.
D: Incorrect. Cardiac monitoring may be necessary for medications associated with QT effects, but monitoring alone does not suppress cortisol synthesis or control the underlying hypercortisolism.
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