Endocrinology Practice Questions

Q: A 62-year-old male with a history of hypertension and type 2 diabetes presents with fatigue and weight loss. His blood pressure is 160/100 mmHg. Laboratory tests show elevated aldosterone and low plasma renin activity. What is the most likely diagnosis?

Primary hyperaldosteronism. ***Primary hyperaldosteronism*** - The combination of **hypertension**, **elevated aldosterone**, and **low plasma renin activity** [2] is characteristic of primary hyperaldosteronism, where the adrenal glands produce excessive aldosterone independently of the renin-angiotensin system. - While fatigue and weight loss are non-specific, persistent hypertension unresponsive to usual treatments and associated with electrolyte imbalances (though not explicitly mentioned here) further points to this diagnosis. *Cushing's syndrome* - This condition is characterized by **excess cortisol**, leading to symptoms like **central obesity**, **moon facies**, **buffalo hump**, and **striae**, which are not described in the patient's presentation. - While hypertension can occur, the key lab findings of **elevated aldosterone and low renin** are not primary features of Cushing's syndrome [3]. *Pheochromocytoma* - A pheochromocytoma is a tumor that secretes **catecholamines**, causing **paroxysmal hypertension**, **tachycardia**, **palpitations**, **sweating**, and **headaches** [1]. - The characteristic laboratory findings would be **elevated plasma metanephrines or normetanephrines**, not elevated aldosterone or low renin. *Secondary hypertension* - This is a broad category, but the specific lab findings of **elevated aldosterone and low renin** in this patient precisely identify the *cause* of the secondary hypertension as primary hyperaldosteronism. - Without these specific findings, other causes of secondary hypertension (e.g., renal artery stenosis, thyroid dysfunction) would need to be considered [4], but the current data points to a specific etiology.

Q: A patient presents with hypotension and hyperkalemia. Which endocrine disorder is most likely to be diagnosed?

Addison's disease. ***Addison's disease*** - **Addison's disease** (primary adrenal insufficiency) leads to decreased production of **mineralocorticoids** (like aldosterone) and **glucocorticoids** (like cortisol) [1], [2]. - The lack of aldosterone causes impaired sodium reabsorption and potassium excretion in the kidneys, leading to **hypotension** (due to volume depletion) and **hyperkalemia** [1]. *Graves' disease (autoimmune hyperthyroidism)* - **Graves' disease** is characterized by **hyperthyroidism**, which typically presents with symptoms like **tachycardia**, **weight loss**, and **heat intolerance** [3]. - It does not directly cause **hypotension** or **hyperkalemia**; electrolyte imbalances are generally not a primary feature. *Hyperaldosteronism (Conn's syndrome)* - **Hyperaldosteronism** is characterized by **excessive aldosterone secretion**, leading to increased sodium reabsorption and potassium excretion. - This typically results in **hypertension** and **hypokalemia**, which are the opposite of the patient's symptoms [1]. *Cushing's syndrome (adrenal hyperfunction)* - **Cushing's syndrome** is caused by excessive **cortisol levels**, leading to symptoms like **weight gain**, **moon facies**, and **hypertension**. - It does not typically cause **hypotension** or **hyperkalemia**; cortisol excess can, in some cases, have mineralocorticoid effects leading to hypokalemia.

Q: A 60-year-old male with generalized anxiety disorder, stable on an SSRI, presents with tremor, insomnia, and palpitations. Laboratory results show increased FT4 and decreased TSH. Evaluate the management approach.

Add propranolol, monitor thyroid function. ***Add propranolol, monitor thyroid function*** - The patient presents with symptoms such as **tremor, insomnia, and palpitations**, along with lab results showing **increased FT4 and decreased TSH**, which are classic signs of **hyperthyroidism**. [1] - **Propranolol**, a beta-blocker, is effective in rapidly alleviating the adrenergic symptoms of hyperthyroidism (e.g., palpitations, tremor, anxiety) while further investigation and definitive treatment for the underlying thyroid condition are pursued. [1] *Switch SSRI to SNRI* - Switching antidepressants would not address the underlying **hyperthyroidism** and its physiological symptoms. - While the patient has a history of anxiety, the current presentation suggests a new **medical condition** rather than solely a psychiatric one requiring an antidepressant change. *Switch SSRI to mirtazapine* - **Mirtazapine** is an antidepressant that would not target the **adrenergic symptoms** or the hormonal imbalance caused by hyperthyroidism. - Switching to an entirely different class of antidepressant in this acute presentation would delay appropriate medical management for the **thyroid dysfunction**. *Lower SSRI dose, add propranolol* - While adding **propranolol** would help with the symptoms, lowering the SSRI dose is not indicated as there is no evidence that the SSRI is causing these new symptoms; the labs clearly point to **hyperthyroidism**. - The patient's **generalized anxiety disorder** is stable on the current SSRI, and dose reduction without a clear reason could exacerbate his anxiety symptoms. [2]

Q: In a patient with suspected pheochromocytoma, which test is essential for diagnosis?

Urine vanillylmandelic acid (VMA). ***Urine vanillylmandelic acid (VMA)*** - **VMA** is a major **metabolite of norepinephrine and epinephrine**, and elevated levels in urine are indicative of increased catecholamine production associated with pheochromocytoma. - While other catecholamine metabolites can be measured, VMA has historically been a reliable diagnostic marker, though often combined with metanephrines for higher sensitivity. *24-hour urine catecholamines and metanephrines* - This test measures the total excretion of **norepinephrine, epinephrine**, and their O-methylated metabolites, **metanephrines**, over a 24-hour period [1]. - It is currently considered the most accurate and sensitive biochemical test for diagnosing pheochromocytoma, with plasma-free metanephrines being a strong alternative, but VMA is still highly relevant [1]. *Plasma renin activity* - **Plasma renin activity** measures the amount of **renin**, an enzyme produced by the kidneys, which is involved in blood pressure regulation. - This test is primarily used in the diagnosis of **primary aldosteronism** and **renovascular hypertension**, not pheochromocytoma [1]. *Blood glucose levels* - While **catecholamines** can cause **hyperglycemia** by increasing glycogenolysis and gluconeogenesis, measuring blood glucose is a non-specific test for pheochromocytoma. - Elevated blood glucose levels could be due to numerous other conditions, such as **diabetes mellitus**, and are not diagnostic for pheochromocytoma.

Q: A patient presents with polyuria, polydipsia, and hyperglycemia. Which diagnostic test would best confirm the diagnosis of diabetes mellitus?

Fasting blood glucose test. ***Fasting blood glucose test*** - A **fasting plasma glucose (FPG)** level of **≥ 126 mg/dL (7.0 mmol/L)** on two separate occasions is diagnostic for diabetes mellitus [1]. - It directly measures the body's ability to regulate glucose after a period of fasting, making it highly specific for diagnosing diabetes [1]. *Oral glucose tolerance test* - While definitive, the **oral glucose tolerance test (OGTT)** is more cumbersome and time-consuming, requiring multiple blood draws after ingesting a glucose solution. - It is typically used when fasting glucose results are equivocal or to diagnose **gestational diabetes**, rather than as a primary confirmation in this scenario. *HbA1c test* - An **HbA1c level of ≥ 6.5%** is diagnostic of diabetes, reflecting average blood glucose levels over the preceding 2-3 months. - However, it can be affected by conditions altering red blood cell lifespan (e.g., anemia, hemoglobinopathies), which might lead to inaccurate results in some patients. *Random blood glucose test* - A **random plasma glucose** **≥ 200 mg/dL (11.1 mmol/L)** in a patient with classic symptoms of hyperglycemia (polyuria, polydipsia) is suggestive of diabetes [1]. - While useful for initial screening or in symptomatic patients, it does not provide the same level of diagnostic confirmation as a fasting or OGTT.

Q: In a diabetic patient with peripheral neuropathy, which of the following changes is most commonly observed?

Decreased sensory perception. ***Decreased sensory perception*** - **Diabetic peripheral neuropathy** primarily affects the longest nerves first, leading to a "stocking-glove" distribution of sensory loss [1]. - This sensory loss often includes the inability to perceive pain, temperature, and touch, increasing the risk of injuries and foot ulcers [1]. *Increased nerve conduction velocity* - **Diabetic neuropathy** characteristically leads to **demyelination** and axonal damage, which slows nerve conduction velocity, rather than increasing it [1]. - An increase in nerve conduction velocity would indicate healthier nerve function, which is contrary to the pathology of neuropathy. *Enhanced autonomic response* - **Diabetic autonomic neuropathy** can lead to a *dysregulation* or *impairment* of autonomic responses, such as orthostatic hypotension or gastroparesis, not an enhancement [2]. - Enhanced autonomic response would imply a heightened and potentially problematic sympathetic or parasympathetic activity that is unrelated to peripheral sensory changes. *Improved pain perception* - **Diabetic neuropathy** typically results in *reduced or altered pain perception*, often leading to painless injuries or a sensation of numbness, rather than improved perception [1]. - Some patients may experience neuropathic pain, which is an abnormal and often severe pain sensation, but this is distinct from improved normal pain perception.

Q: A 35-year-old woman presents with a headache and is found to have elevated intracranial pressure. An MRI shows an enlarged pituitary gland with suprasellar extension. What is the most likely diagnosis?

Pituitary adenoma. ***Pituitary adenoma*** - An **enlarged pituitary gland** with **suprasellar extension** is highly characteristic of a pituitary adenoma [3], which can cause symptoms like headache and elevated intracranial pressure [1]. - Pituitary adenomas are common benign tumors that originate from the pituitary gland and can grow to compress surrounding structures [3]. *Meningioma* - Meningiomas typically arise from the **meninges** and are usually located over the convexities of the brain or along the skull base, not primarily within the pituitary fossa [2]. - While they can cause headaches and elevated intracranial pressure, they would not present as an **enlarged pituitary gland** on MRI. *Craniopharyngioma* - Craniopharyngiomas are **congenital slow-growing tumors** that typically arise from Rathke's pouch remnants, often in the **suprasellar region**. - While they can cause suprasellar mass effects and elevated intracranial pressure, they usually do not originate within or primarily enlarge the pituitary gland itself. *Pituitary apoplexy* - Pituitary apoplexy is an **acute hemorrhagic or ischemic infarction** of a pituitary adenoma, presenting with sudden onset of severe headache, visual disturbance, and often hypopituitarism. - While it involves the pituitary gland and can cause severe symptoms, the question describes a more chronic presentation of an "enlarged pituitary gland" rather than an acute event.

Q: In assessing the risk of osteoporosis in postmenopausal women, which factor is considered the most significant?

Advanced age. ***Advanced age*** - **Advanced age** is the most significant non-modifiable risk factor for osteoporosis because bone density naturally declines with aging, increasing fragility and fracture risk [1]. - After menopause, the sharp decrease in **estrogen** accelerates bone loss, making age an even more potent factor in postmenopausal women [1], [2]. *Calcium intake* - Adequate **calcium intake** is essential for bone health, but it is a preventative factor rather than the most significant risk factor for established osteoporosis in postmenopausal women [1], [3]. - While chronic low intake can contribute to bone loss, it is less impactful on overall risk than age-related hormonal changes. *Family history of osteoporosis* - A **family history of osteoporosis** is an important risk factor, as genetic predisposition influences peak bone mass and rates of bone loss. - However, its influence is mediated through genetic pathways that become more clinically relevant with increasing age. *Physical activity level* - **Physical activity**, especially weight-bearing exercise, helps maintain bone density and strength [1], [3]. - A sedentary lifestyle increases osteoporosis risk, but its impact is generally secondary to the drastic hormonal changes linked with aging, especially post-menopause [1].

Q: A patient presents with nocturnal muscle cramps and a recent onset of hypertension. Which endocrine disorder should be considered?

Pheochromocytoma. ***Pheochromocytoma*** - **Pheochromocytoma** can cause episodic hypertension, often associated with symptoms like **palpitations**, headache, and **sweating**, which can manifest as nocturnal events or muscle cramps due to catecholamine surge. - The elevated **catecholamines** lead to vasoconstriction and increased cardiac output, resulting in hypertension and potentially **muscle disturbances**. *Hyperthyroidism* - While hyperthyroidism can cause hypertension, it typically presents with symptoms like **weight loss**, heat intolerance, **tachycardia**, and nervousness, rather than nocturnal muscle cramps as a primary complaint. - Muscle weakness and fatigue are more common in hyperthyroidism than cramps. *Primary hyperparathyroidism* - Primary hyperparathyroidism primarily affects **calcium metabolism**, leading to hypercalcemia; symptoms include **fatigue**, kidney stones, and bone pain. - Hypertension can be present, but **muscle cramps** are not a typical or prominent feature, and muscle weakness or bone-related issues are more characteristic. *Cushing's syndrome* - **Cushing's syndrome** is characterized by symptoms like central obesity, moon facies, striae, and **proximal muscle weakness**, all due to excess cortisol. - Although hypertension is common, nocturnal muscle cramps are not a hallmark symptom of **Cushing's syndrome**, and the muscle weakness is usually distinct from cramping.

Q: A 45-year-old patient presents with muscle weakness and hyperpigmentation. Which condition is indicated by increased ACTH levels?

Addison's disease. ***Addison's disease*** - **Addison's disease** (primary adrenal insufficiency) leads to decreased cortisol production, which in turn causes a **compensatory increase in ACTH** [1]. - **High ACTH** stimulates melanocytes, resulting in characteristic **hyperpigmentation** along with symptoms of adrenal insufficiency like muscle weakness [1]. *Cushing's disease* - Cushing's disease is caused by an **ACTH-producing pituitary adenoma**, leading to **excessive cortisol production** [2]. - While ACTH levels are high, the primary presentation is typically **Cushingoid features** (e.g., central obesity, moon facies), and **hyperpigmentation** is less prominent than in Addison's disease. *Secondary hyperparathyroidism* - This condition involves **excessive parathyroid hormone (PTH)** secretion in response to hypocalcemia or vitamin D deficiency, unrelated to ACTH. - Symptoms are primarily related to **bone and mineral metabolism**, not muscle weakness nor hyperpigmentation caused by ACTH. *Pheochromocytoma* - A pheochromocytoma is a tumor of the adrenal medulla that secretes **catecholamines** (epinephrine and norepinephrine). - It causes symptoms like **hypertension, palpitations, and headaches**, and has no direct relationship with ACTH levels, muscle weakness, or hyperpigmentation.

Question 1

A 62-year-old male with a history of hypertension and type 2 diabetes presents with fatigue and weight loss. His blood pressure is 160/100 mmHg. Laboratory tests show elevated aldosterone and low plasma renin activity. What is the most likely diagnosis?

Accepted Answer

Primary hyperaldosteronism

Answer

Cushing's syndrome

Answer

Pheochromocytoma

Answer

Secondary hypertension

Question 2

A patient presents with hypotension and hyperkalemia. Which endocrine disorder is most likely to be diagnosed?

Accepted Answer

Addison's disease

Answer

Graves' disease (autoimmune hyperthyroidism)

Answer

Hyperaldosteronism (Conn's syndrome)

Answer

Cushing's syndrome (adrenal hyperfunction)

Question 3

A 60-year-old male with generalized anxiety disorder, stable on an SSRI, presents with tremor, insomnia, and palpitations. Laboratory results show increased FT4 and decreased TSH. Evaluate the management approach.

Accepted Answer

Add propranolol, monitor thyroid function

Answer

Switch SSRI to mirtazapine

Answer

Switch SSRI to SNRI

Answer

Lower SSRI dose, add propranolol

Question 4

In a patient with suspected pheochromocytoma, which test is essential for diagnosis?

Accepted Answer

Urine vanillylmandelic acid (VMA)

Answer

Plasma renin activity

Answer

Blood glucose levels

Answer

24-hour urine catecholamines and metanephrines

Question 5

A patient presents with polyuria, polydipsia, and hyperglycemia. Which diagnostic test would best confirm the diagnosis of diabetes mellitus?

Accepted Answer

Fasting blood glucose test

Answer

Oral glucose tolerance test

Answer

Random blood glucose test

Answer

HbA1c test

Question 6

In a diabetic patient with peripheral neuropathy, which of the following changes is most commonly observed?

Accepted Answer

Decreased sensory perception

Answer

Increased nerve conduction velocity

Answer

Enhanced autonomic response

Answer

Improved pain perception

Question 7

A 35-year-old woman presents with a headache and is found to have elevated intracranial pressure. An MRI shows an enlarged pituitary gland with suprasellar extension. What is the most likely diagnosis?

Accepted Answer

Pituitary adenoma

Answer

Meningioma

Answer

Craniopharyngioma

Answer

Pituitary apoplexy

Question 8

In assessing the risk of osteoporosis in postmenopausal women, which factor is considered the most significant?

Accepted Answer

Advanced age

Answer

Family history of osteoporosis

Answer

Calcium intake

Answer

Physical activity level

Question 9

A patient presents with nocturnal muscle cramps and a recent onset of hypertension. Which endocrine disorder should be considered?

Accepted Answer

Pheochromocytoma

Answer

Primary hyperparathyroidism

Answer

Hyperthyroidism

Answer

Cushing's syndrome

Question 10

A 45-year-old patient presents with muscle weakness and hyperpigmentation. Which condition is indicated by increased ACTH levels?

Accepted Answer

Addison's disease

Answer

Cushing's disease

Answer

Secondary hyperparathyroidism

Answer

Pheochromocytoma

Endocrinology — MCQs

Endocrinology — MCQs

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