Endocrinology Practice Questions

Q: A patient presents with palpitations, headache, and sweating. His BP is $180/100 \mathrm{mmHg}$ . 24-hour urinary metanephrine values are elevated. What is the diagnosis?

Pheochromocytoma. Pheochromocytoma - The constellation of symptoms—palpitations, episodic sweating, severe headache, and hypertension (the classic triad)—is highly suggestive of excessive catecholamine release. - The diagnosis is confirmed by the elevated 24-hour urinary metanephrines (metabolites of epinephrine and norepinephrine), which is the definitive biochemical hallmark of this adrenal medullary tumor. Carcinoid tumor - This tumor primarily secretes serotonin and other vasoactive substances, leading to symptoms like flushing, diarrhea, and bronchospasm (carcinoid syndrome) [1]. - The biochemical marker for this condition is elevated urinary 5-hydroxyindoleacetic acid (5-HIAA), not metanephrines. Carcinoid crisis - This represents a severe, life-threatening exacerbation of carcinoid syndrome involving severe flushing, profound hypotension, and cardiac arrhythmias. - It is typically an acute event triggered by stressors such as surgery or chemotherapy, unlike the chronic presentation described. Neuroblastoma - This malignant tumor of the neural crest primarily affects infants and young children (usually under 5 years old), making it unlikely in an adult patient. - Although it can secrete catecholamines, its primary presenting features usually include an abdominal mass, fever, and metastasis, and the key diagnostic marker is often high urinary VMA (Vanillylmandelic acid) and HVA (Homovanillic acid).

Q: A 23-year-old female visited the clinician with a solitary thyroid nodule and was advised for thyroid function tests where TSH level is 27.3 mU/L, T3 is 1.24 ng/mL, and T4 is 4.87 μg/dL. Which of the following manifestations is true regarding the condition?

Weight gain. ***Weight gain***- The patient's thyroid function tests (TFTs), showing a **highly elevated TSH** (27.3 mU/L) and **low T4** (4.87 μg/dL), confirm a diagnosis of **Primary Hypothyroidism** [1].- Weight gain is a classic symptom of hypothyroidism, resulting from reduced **basal metabolic rate** and frequently accompanied by **fluid retention** leading to *myxedema* [2]. *Heat intolerance*- Heat intolerance is a characteristic feature of **Hyperthyroidism**, where excess thyroid hormone increases heat production.- Patients with hypothyroidism typically experience **cold intolerance** due to decreased thermogenesis [2]. *Tachycardia*- **Tachycardia** (increased heart rate) is a common cardiovascular manifestation of **Hyperthyroidism** due to enhanced adrenergic effects [2].- Hypothyroidism generally leads to **bradycardia** (slow heart rate) and reduced cardiac contractility [2]. *Diarrhea*- Diarrhea is associated with **Hyperthyroidism** because of increased gastrointestinal motility.- Patients suffering from hypothyroidism commonly present with decreased bowel motility, leading to **constipation** [2].

Q: A patient with a history of Graves' disease underwent I-131 ablation therapy. Which of the following is the most likely long-term side effect of this treatment?

Hypothyroidism. ***Hypothyroidism*** - The primary mechanism of **I-131 ablation** is the destruction of functional thyroid tissue by radiation, leading to a permanent reduction in hormone production. - **Hypothyroidism** is the most common and often inevitable long-term complication following successful **radioiodine ablation** for conditions like Graves' disease or thyroid cancer, occurring in 80-90% of patients within the first year [1]. - Requires lifelong thyroid hormone replacement therapy. *Acute Thyroiditis* - This is a possible immediate side effect, known as **radiation thyroiditis**, causing transient local pain and tenderness within days to weeks of treatment. - It is a short-term inflammatory response due to radiation-induced thyroid cell damage, not the defining long-term side effect [1]. - Usually self-limiting and managed with NSAIDs or corticosteroids. *Hyperthyroidism* - Although an initial transient surge of thyroid hormones (due to tissue destruction releasing stored hormone) can occur within the first 1-2 weeks after I-131, this is temporary [2]. - The treatment's primary purpose is to permanently cure hyperthyroidism by destroying thyroid tissue. - Persistent or recurrent hyperthyroidism would indicate treatment failure, not a side effect. *Thyroid Storm* - A **thyroid storm** is an acute, life-threatening exacerbation of hyperthyroidism usually precipitated by factors like infection, surgery, or trauma [2]. - While extremely rare, radioiodine therapy can theoretically precipitate a storm in inadequately prepared, severely hyperthyroid patients [2]. - This is **not a likely or common side effect** compared to permanent hypothyroidism, and proper pre-treatment with antithyroid drugs minimizes this risk.

Q: A hypertensive patient’s lab results reveal hypernatremia, hypokalemia, and metabolic alkalosis. What is the most probable diagnosis?

Conn's Syndrome. ***Conn's Syndrome***- This condition, known as primary **hyperaldosteronism**, is defined by autonomous overproduction of aldosterone, leading to volume expansion and **hypertension** [1].- Aldosterone acts on the principal cells of the collecting duct to increase Na+ reabsorption (causing hypernatremia) while simultaneously promoting K+ and H+ excretion (causing **hypokalemia** and **metabolic alkalosis**) [2].*Addison’s Disease*- Addison’s disease is primary adrenal insufficiency, characterized by deficiency of mineralocorticoids and glucocorticoids [3].- This lack of aldosterone leads to impaired Na+ reabsorption and deficient K+ excretion, resulting in **hyponatremia** and **hyperkalemia** (the opposite of the clinical picture).*Diabetes Insipidus*- Diabetes Insipidus (DI) is a disorder of insufficient ADH action, resulting in polyuria and profound free water loss leading to **hypernatremia**.- DI does not arise from mineralocorticoid dysfunction, thus it would not typically cause **hypokalemia** or metabolic alkalosis.*Cushing's Disease*- Cushing's disease involves excess **cortisol** (a glucocorticoid), which can cause hypertension and occasionally hypokalemia.- However, the combination of **hypernatremia**, significant **hypokalemia**, and severe **metabolic alkalosis** strongly points toward primary **mineralocorticoid excess** rather than glucocorticoid excess [1].

Q: Which drug is preferred for management of diabetes in a patient with cardiac and renal failure?

SGLT2 inhibitors. ***SGLT2 inhibitors*** - These agents are strongly recommended due to their proven benefits in reducing **heart failure (HF)** hospitalizations and **cardiovascular (CV) mortality**. - They also offer robust **reno-protection**, slowing the decline of **eGFR** and reducing albuminuria, making them ideal when both cardiac and renal failure coexist. *Pioglitazone* - This drug class (**thiazolidinediones**) is known to cause **fluid retention** and peripheral edema, thus potentially exacerbating or precipitating **congestive heart failure (CHF)**; it is therefore generally avoided [1]. - It is not associated with improved long-term renal or cardiovascular outcomes in the way that SGLT2 inhibitors are. *Metformin* - While a foundational drug, Metformin is contraindicated in severe **renal failure** (e.g., eGFR <30 mL/min/1.73m²) due to the increased risk of potentially fatal **lactic acidosis**. - Although safe in mild to moderate CKD, it lacks the specific, compelling evidence for reducing progression of **heart failure** or **CKD** compared to SGLT2 inhibitors. *Sulfonylureas* - These drugs primarily increase the risk of **hypoglycemia**, which is heightened in patients with **renal insufficiency** due to altered drug metabolism and clearance. - They provide no demonstrated **cardiovascular** or **renal protective benefits** and may be associated with weight gain.

Q: A 49-year-old male presents with recurrent episodes of watery diarrhoea, dehydration, hypokalemia, and achlorhydria. Which of the following neuroendocrine tumours can be responsible for these symptoms?

VIPoma. A 49-year-old male presents with recurrent episodes of watery diarrhoea, dehydration, hypokalemia, and achlorhydria. Which of the following neuroendocrine tumours can be responsible for these symptoms? ***VIPoma***- The constellation of symptoms—watery diarrhoea, dehydration, hypokalemia, and achlorhydria—is known as **WDHA syndrome** (Watery Diarrhea, Hypokalemia, Achlorhydria), which is pathognomonic for a VIP-secreting tumour. [1] - **Vasoactive Intestinal Peptide (VIP)** acts as an intestinal secretagogue, leading to massive secretion of water and electrolytes, causing profound secretory diarrhea and subsequent life-threatening **hypokalemia** and dehydration. [1] *Insulinoma* - This tumour hypersecretes **insulin**, leading to severe symptoms of **hypoglycemia** (neuroglycopenic symptoms) which are typically worse in the fasting state. [2] - Insulinoma does not cause secretory diarrhea, hypokalemia, or achlorhydria. [2] *Somatostatinoma* - This tumor typically presents with the classic triad of **diabetes mellitus**, **gallstones (cholelithiasis)**, and **steatorrhea** (due to inhibition of pancreatic enzyme secretion). - While diarrhea can occur due to malabsorption, the overwhelming secretory diarrhea and achlorhydria defining this case are not characteristic. *Glucagonoma* - The primary clinical manifestations of glucagonoma include **necrolytic migratory erythema** (a distinctive skin rash), mild **diabetes mellitus**, and often **weight loss**. - It does not cause massive watery diarrhea leading to hypokalemia and achlorhydria.

Q: What is the most common cause of Cushing's disease in a 60-year-old male?

Pituitary microadenoma. ***Pituitary microadenoma*** - Cushing's **Disease** is specifically defined as hypercortisolism caused by an ACTH-secreting tumor of the pituitary gland, which is typically a **microadenoma** (<10 mm) [2]. - Pituitary adenomas are the most common cause of **endogenous** ACTH-dependent hypercortisolism (Cushing's Disease), regardless of the patient's age or sex [1]. *Small-cell lung cancer* - This is the most common cause of **ectopic ACTH syndrome**, which is a form of Cushing's **Syndrome**, not Cushing's Disease [1]. - Ectopic secretion generally leads to rapidly progressive, severe hypercortisolism and is often associated with hypokalemic metabolic alkalosis. *Adrenal tumor* - Adrenal tumors (adenomas or carcinomas) cause **ACTH-independent** Cushing's syndrome by directly overproducing cortisol [1]. - In this etiology, the pituitary gland is suppressed, resulting in very low or undetectable plasma **ACTH levels** [3]. *Ectopic ACTH syndrome* - While ectopic ACTH syndrome (often from bronchial carcinoids or small-cell lung cancer) is a significant cause of Cushing's **Syndrome** in elderly males, it is not the definition of Cushing's **Disease**. [1] - Ectopic sources produce ACTH unresponsive to **high-dose dexamethasone suppression** tests, unlike most cases of Cushing's Disease.

Q: A patient presents with complaints of sudden onset headache, palpitation, and profuse sweating. The patient has had multiple similar episodes in the past. During these episodes, the patient's blood pressure is elevated. A 24-hour urinary metanephrine is elevated. What is the most likely diagnosis?

Pheochromocytoma. ***Pheochromocytoma***- This clinical presentation—paroxysmal episodes of headache, palpitations, and profuse sweating (the classic triad)—coupled with elevated blood pressure strongly suggests a **pheochromocytoma** (a tumor of the adrenal medulla secreting catecholamines). - The definitive biochemical confirmation is the elevated 24-hour urinary **metanephrines** and normetanephrines, which are breakdown products of epinephrine and norepinephrine. *Addison's disease* - This condition involves primary adrenal *insufficiency* (hypocortisolism), which typically presents with **hypotension**, fatigue, weight loss, and **hyperpigmentation**, not hypertensive crises. - It involves decreased production of adrenal hormones, not the episodic overproduction of **catecholamines** seen here. *Renal artery stenosis* - This is a cause of secondary hypertension due to chronic activation of the **Renin-Angiotensin-Aldosterone System (RAAS)**, leading to persistent, non-paroxysmal elevation of blood pressure. - It would not cause the specific triad of episodic symptoms (headache, sweating, palpitations) or lead to elevated **urinary metanephrines**. *Hyperthyroidism* - While it can cause palpitations, tremor, and systolic hypertension, these symptoms are typically chronic and sustained, lacking the sudden paroxysmal nature described. - The primary biochemical abnormality involves elevated **T3/T4 hormones**, not the excessive urinary excretion of **metanephrines** as detailed in this case.

Q: A patient is diagnosed with acromegaly. Transsphenoidal surgery is not feasible. Which of the following drugs is preferred for the medical management of this patient?

Lanreotide depot formulation. ***Lanreotide depot formulation***- It is a **somatostatin analog** (SSA) and a first-line medical therapy for acromegaly, particularly when surgery fails or is contraindicated [1].- SSAs normalize **GH (Growth Hormone)** and **IGF-1 (Insulin-like Growth Factor-1)** levels by inhibiting pituitary GH secretion [1].*Terlipressin*- It is primarily an analog of **vasopressin** used to treat **esophageal variceal bleeding** and hepatorenal syndrome.- It has no role in reducing pituitary growth hormone hypersecretion characteristic of acromegaly.*Ketoconazole*- It is an **antifungal agent** that also inhibits **steroidogenesis** (glucocorticoids, androgens).- Its primary hormonal use is in treating **Cushing's syndrome** (due to cortisol inhibition), not acromegaly.*Leuprolide*- This is a **GnRH agonist** used primarily to treat conditions like **prostate cancer**, **endometriosis**, and **precocious puberty**.- It acts on the hypothalamic-pituitary-gonadal axis and does not directly target GH-secreting tumors.

Q: A diabetic patient developed DVT with a necrolytic migratory rash. What is the most likely diagnosis?

Glucagonoma. ***Glucagonoma***- This paraneoplastic syndrome, caused by excessive glucagon secretion, is classically associated with the triad of **diabetes mellitus** (due to glucagon's counter-regulatory effect), **necrolytic migratory erythema (NME)**, and a high incidence of **venous thrombosis** (DVT/PE).- The classic rash, **NME**, is an erythematous, scaling rash that begins peripherally and migrates, often causing eroded, painful lesions [1].*Insulinoma*- The primary manifestation is **hypoglycemia** (Whipple's triad), leading to neuroglycopenic symptoms like confusion and seizures.- This tumor does not cause the characteristic **necrolytic migratory rash** or have a strong association with DVT.*Gastrinoma*- Gastrinomas cause **Zollinger-Ellison syndrome**, characterized by severe, refractory **peptic ulcer disease** (PUD) and chronic diarrhea.- The clinical presentation lacks the key features of hyperglycemia, DVT, and **necrolytic migratory erythema (NME)**.*VIPoma*- VIPomas cause the **WDHA syndrome** (**W**atery **D**iarrhea, **H**ypokalemia, **A**chlorhydria), leading to profound dehydration and electrolyte imbalances.- This tumor is not associated with the pathogenesis of **necrolytic migratory erythema** or the hypercoagulable state responsible for DVT.

Question 1

A patient presents with palpitations, headache, and sweating. His BP is $180/100 \mathrm{mmHg}$ . 24-hour urinary metanephrine values are elevated. What is the diagnosis?

Accepted Answer

Pheochromocytoma

Answer

Carcinoid crisis

Answer

Neuroblastoma

Answer

Carcinoid tumor

Question 2

A 23-year-old female visited the clinician with a solitary thyroid nodule and was advised for thyroid function tests where TSH level is 27.3 mU/L, T3 is 1.24 ng/mL, and T4 is 4.87 μg/dL. Which of the following manifestations is true regarding the condition?

Accepted Answer

Weight gain

Answer

Diarrhea

Answer

Tachycardia

Answer

Heat intolerance

Question 3

A patient with a history of Graves' disease underwent I-131 ablation therapy. Which of the following is the most likely long-term side effect of this treatment?

Accepted Answer

Hypothyroidism

Answer

Thyroid Storm

Answer

Hyperthyroidism

Answer

Acute Thyroiditis

Question 4

A hypertensive patient’s lab results reveal hypernatremia, hypokalemia, and metabolic alkalosis. What is the most probable diagnosis?

Accepted Answer

Conn's Syndrome

Answer

Addison’s Disease

Answer

Cushing's Disease

Answer

Diabetes Insipidus

Question 5

Which drug is preferred for management of diabetes in a patient with cardiac and renal failure?

Accepted Answer

SGLT2 inhibitors

Answer

Pioglitazone

Answer

Metformin

Answer

Sulfonylureas

Question 6

A 49-year-old male presents with recurrent episodes of watery diarrhoea, dehydration, hypokalemia, and achlorhydria. Which of the following neuroendocrine tumours can be responsible for these symptoms?

Accepted Answer

VIPoma

Answer

Glucagonoma

Answer

Insulinoma

Answer

Somatostatinoma

Question 7

What is the most common cause of Cushing's disease in a 60-year-old male?

Accepted Answer

Pituitary microadenoma

Answer

Small-cell lung cancer

Answer

Adrenal tumor

Answer

Ectopic ACTH syndrome

Question 8

A patient presents with complaints of sudden onset headache, palpitation, and profuse sweating. The patient has had multiple similar episodes in the past. During these episodes, the patient's blood pressure is elevated. A 24-hour urinary metanephrine is elevated. What is the most likely diagnosis?

Accepted Answer

Pheochromocytoma

Answer

Renal artery stenosis

Answer

Hyperthyroidism

Answer

Addison's disease

Question 9

A patient is diagnosed with acromegaly. Transsphenoidal surgery is not feasible. Which of the following drugs is preferred for the medical management of this patient?

Accepted Answer

Lanreotide depot formulation

Answer

Terlipressin

Answer

Ketoconazole

Answer

Leuprolide

Question 10

A diabetic patient developed DVT with a necrolytic migratory rash. What is the most likely diagnosis?

Accepted Answer

Glucagonoma

Answer

VIPoma

Answer

Insulinoma

Answer

Gastrinoma

Endocrinology — MCQs

Endocrinology — MCQs

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