Endocrinology — MCQs
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Advanced bone age is seen in all conditions except which of the following?
Diabetic ketoacidosis is best managed by?
A 36-year-old female presents with symptoms of hyperparathyroidism, a tumor in the pancreas, adrenal cortical hyperplasia, pituitary adenomas, an islet cell tumor, and cutaneous angiofibromas. What is the diagnosis?
Increased urinary excretion of calcium is seen in which of the following conditions?
Which of the following is a parenteral agent used in the management of diabetes mellitus?
All are true about pheochromocytoma except?
A patient with an endocrine abnormality shows a 'hung up' reflex. Which of the following conditions causes a 'hung up' reflex?
Increased anion gap is a characteristic feature of which condition?
What is the most common presentation of Multiple Endocrine Neoplasia type 1 (MEN I)?
Which of the following conditions causes hypercalcemia with a normal or low parathyroid hormone (PTH) level?
Endocrinology Indian Medical PG Practice Questions and MCQs
Question 131: Advanced bone age is seen in all conditions except which of the following?
- A. Marfan's syndrome (Correct Answer)
- B. Congenital adrenal hyperplasia
- C. Precocious puberty
- D. Obesity
Explanation: **Explanation:** Bone age is a measure of skeletal maturity, typically assessed via X-ray of the left hand and wrist. **Advanced bone age** occurs when skeletal maturation is faster than chronological age, usually due to early or excessive exposure to sex steroids or growth-promoting hormones. [1] **Why Marfan’s Syndrome is the Correct Answer:** In **Marfan’s syndrome**, patients exhibit tall stature and arachnodactyly due to a genetic defect in fibrillin-1, which leads to connective tissue laxity and longitudinal overgrowth of long bones. However, this is a structural/skeletal dysplasia rather than a hormonal maturation issue. Consequently, the **bone age in Marfan’s syndrome is typically normal** (concordant with chronological age), making it the "except" in this list. **Analysis of Incorrect Options:** * **Congenital Adrenal Hyperplasia (CAH):** Excess adrenal androgens cause rapid linear growth initially but lead to premature closure of epiphyseal plates. This results in significantly **advanced bone age**. * **Precocious Puberty:** Early secretion of estrogen or testosterone triggers premature skeletal maturation and epiphyseal fusion, leading to **advanced bone age**. * **Obesity:** Childhood obesity is associated with increased levels of insulin and leptin, and the peripheral conversion of androgens to estrogens in adipose tissue. This often leads to accelerated linear growth and **advanced bone age**. **High-Yield Clinical Pearls for NEET-PG:** * **Delayed Bone Age:** Seen in Constitutional Delay of Growth and Puberty (CDGP), Hypothyroidism, Growth Hormone deficiency, and Malnutrition. * **Advanced Bone Age:** Seen in CAH, Precocious puberty, Hyperthyroidism, and Exogenous androgen/estrogen exposure. * **Rule of Thumb:** If a child is tall for their age but has an advanced bone age, their final adult height potential is often reduced due to early epiphyseal fusion. [1]
Question 132: Diabetic ketoacidosis is best managed by?
- A. Crystalline insulin given intravenously. (Correct Answer)
- B. Human insulin given intramuscularly.
- C. Lente insulin given subcutaneously.
- D. Isophane insulin given intradermally.
Explanation: **Explanation:** The management of **Diabetic Ketoacidosis (DKA)** focuses on correcting hyperglycemia, acidosis, and dehydration [1]. The gold standard for glycemic control in DKA is the administration of **Crystalline (Regular) Insulin via the Intravenous (IV) route.** **Why Option A is Correct:** * **Pharmacokinetics:** Regular insulin given IV has an immediate onset of action and a very short half-life (approx. 5–10 minutes). This allows for rapid titration based on hourly blood glucose monitoring. * **Tissue Perfusion:** Patients in DKA are often severely dehydrated and in a state of peripheral vasoconstriction [1]. IV administration bypasses the skin and muscle, ensuring 100% bioavailability regardless of the patient's circulatory status. **Why Other Options are Incorrect:** * **Option B (Intramuscular):** While IM insulin can be used in mild cases if IV access is unavailable, it is less predictable and more painful. Absorption is delayed compared to the IV route. * **Option C (Lente/Subcutaneous):** Lente is an intermediate-acting insulin. Subcutaneous absorption is significantly impaired in DKA due to dehydration and poor skin perfusion. Furthermore, long-acting insulins cannot be quickly adjusted if hypoglycemia occurs [2]. * **Option D (Isophane/Intradermal):** Isophane (NPH) is intermediate-acting and not suitable for acute emergencies. The intradermal route is not used for insulin therapy. **High-Yield Clinical Pearls for NEET-PG:** * **Protocol:** Start with an IV bolus (0.1 U/kg) followed by a continuous infusion (0.1 U/kg/hr). * **The Goal:** The aim is to reduce blood glucose by **50–70 mg/dL per hour**. * **Potassium Rule:** Never start insulin if serum Potassium is **<3.3 mEq/L**, as insulin shifts potassium intracellularly, potentially causing fatal arrhythmias [1]. * **Switching:** Transition to subcutaneous insulin only when the **anion gap has closed**, the patient is conscious, and they can tolerate oral intake [2].
Question 133: A 36-year-old female presents with symptoms of hyperparathyroidism, a tumor in the pancreas, adrenal cortical hyperplasia, pituitary adenomas, an islet cell tumor, and cutaneous angiofibromas. What is the diagnosis?
- A. Multiple Endocrine Neoplasia Type I (MEN I) (Correct Answer)
- B. Multiple Endocrine Neoplasia Type IIA (MEN 2A)
- C. Multiple Endocrine Neoplasia Type IIB (MEN 2B)
- D. Multiple Endocrine Neoplasia Type IIC (MEN 2C)
Explanation: The patient presents with the classic triad of **Multiple Endocrine Neoplasia Type I (MEN 1)**, also known as **Wermer’s Syndrome**. This autosomal dominant condition is caused by a mutation in the *MEN1* gene (encoding the protein Menin). The diagnosis is confirmed by the presence of the **"3 Ps"**: 1. **Parathyroid:** Hyperparathyroidism (most common initial manifestation, usually due to multiglandular hyperplasia). 2. **Pancreas:** Enteropancreatic tumors (e.g., Gastrinomas, Insulinomas, or non-functional islet cell tumors). 3. **Pituitary:** Adenomas (most commonly Prolactinomas). Additionally, MEN 1 is associated with non-endocrine manifestations such as **cutaneous angiofibromas**, collagenomas, lipomas, and **adrenal cortical tumors** (usually non-functional hyperplasia), all of which are present in this clinical vignette. [1] **Why other options are incorrect:** * **MEN 2A (Sipple Syndrome):** Characterized by Medullary Thyroid Carcinoma (MTC), Pheochromocytoma, and Parathyroid hyperplasia. It does not involve the pituitary or pancreas. [1] * **MEN 2B:** Characterized by MTC, Pheochromocytoma, Mucosal neuromas, and Marfanoid habitus. It lacks parathyroid involvement. * **MEN 2C:** This is not a standard clinical classification in current medical literature; MEN 2 is strictly divided into 2A, 2B, and Familial MTC. **High-Yield Clinical Pearls for NEET-PG:** * **Inheritance:** Autosomal Dominant; Gene: *MEN1* (Chromosome 11q13). * **Most common feature:** Primary Hyperparathyroidism (>95% of patients). * **Most common pancreatic tumor:** Gastrinoma (Zollinger-Ellison Syndrome). * **Screening:** Annual biochemical screening (Calcium, PTH, Gastrin, Prolactin) is recommended for first-degree relatives. [1]
Question 134: Increased urinary excretion of calcium is seen in which of the following conditions?
- A. Sarcoidosis
- B. Glucocorticoid excess
- C. Wilson's disease
- D. All the above (Correct Answer)
Explanation: Hypercalciuria (increased urinary calcium excretion) occurs through various pathophysiological mechanisms involving bone resorption, intestinal absorption, and renal tubular handling. **1. Sarcoidosis:** In sarcoidosis, activated macrophages within granulomas contain the enzyme **1-alpha-hydroxylase**. This enzyme converts 25-hydroxyvitamin D into **1,25-dihydroxyvitamin D (Calcitriol)** in an unregulated manner [1]. Elevated calcitriol levels lead to increased intestinal calcium absorption and bone resorption, resulting in hypercalcemia and subsequent hypercalciuria as the kidneys attempt to excrete the excess load [1]. **2. Glucocorticoid Excess (Cushing’s Syndrome/Exogenous Steroids):** Glucocorticoids induce hypercalciuria primarily by **inhibiting renal tubular reabsorption of calcium**. Additionally, they decrease intestinal calcium absorption (leading to secondary hyperparathyroidism) and increase bone resorption, both of which contribute to a higher filtered load of calcium. **3. Wilson’s Disease:** This condition can cause **Fanconi Syndrome** (Type 2 Proximal Renal Tubular Acidosis) due to copper deposition in the proximal renal tubules. The resulting tubular dysfunction leads to a "leak" of various substances, including calcium, glucose, and amino acids, into the urine. **High-Yield Clinical Pearls for NEET-PG:** * **Thiazide Diuretics:** These *decrease* urinary calcium (used in treating calcium stones). * **Loop Diuretics (Furosemide):** These *increase* urinary calcium ("Loops lose calcium"). * **Williams Syndrome:** Associated with idiopathic hypercalcemia and hypercalciuria. * **Vitamin D Toxicity:** A classic cause of hypercalciuria due to excessive intestinal absorption [1].
Question 135: Which of the following is a parenteral agent used in the management of diabetes mellitus?
- A. Rosiglitazone
- B. Exenatide (Correct Answer)
- C. Repaglinide
- D. Canagliflozin
Explanation: **Explanation:** The correct answer is **Exenatide**. **Why Exenatide is correct:** Exenatide is a **GLP-1 Receptor Agonist** (Incretin mimetic). These agents work by stimulating glucose-dependent insulin secretion, suppressing glucagon release, and slowing gastric emptying [1]. Because GLP-1 agonists are peptide-based molecules, they are susceptible to degradation by gastrointestinal enzymes if taken orally. Therefore, they must be administered via **subcutaneous injection** (parenteral route) [1]. **Why the other options are incorrect:** * **Rosiglitazone (Option A):** A Thiazolidinedione (TZD) that acts as a PPAR-gamma agonist to improve insulin sensitivity [1]. It is administered **orally**. * **Repaglinide (Option B):** A Meglitinide (Glinide) that acts as a short-acting insulin secretagogue by closing ATP-sensitive potassium channels. It is administered **orally** before meals. * **Canagliflozin (Option D):** An SGLT-2 inhibitor that prevents glucose reabsorption in the proximal convoluted tubule of the kidney. It is administered **orally**. **High-Yield Clinical Pearls for NEET-PG:** * **Parenteral Antidiabetic Agents:** Include all **Insulins**, **GLP-1 Agonists** (e.g., Liraglutide, Dulaglutide), and **Pramlintide** (an Amylin analogue). * **Exception:** *Semaglutide* is the only GLP-1 agonist currently available in both oral and injectable forms. * **Key Side Effects:** GLP-1 agonists are associated with weight loss (beneficial in obese diabetics) but carry a risk of pancreatitis and are contraindicated in patients with a history of Medullary Thyroid Carcinoma (MTC). * **Weight Neutrality:** Metformin and DPP-4 inhibitors are weight neutral; GLP-1 agonists and SGLT-2 inhibitors promote weight loss; Sulfonylureas, TZDs, and Insulin cause weight gain.
Question 136: All are true about pheochromocytoma except?
- A. 90% are malignant (Correct Answer)
- B. 95% occur in the abdomen
- C. They secrete catecholamines
- D. They arise from sympathetic ganglia
Explanation: Explanation: Pheochromocytoma is a catecholamine-secreting tumor derived from chromaffin cells. Understanding the "Rule of 10s" is crucial for solving this question. 1. Why Option A is the Correct Answer (The False Statement): Historically, pheochromocytoma follows the "Rule of 10s," which states that only 10% of cases are malignant, while 90% are benign. Therefore, the statement that "90% are malignant" is factually incorrect. Malignancy is defined not by histology, but by the presence of tumor cells in non-chromaffin sites (e.g., bone, liver, or lymph nodes). 2. Analysis of Other Options: * Option B: Approximately 95% occur in the abdomen. While 85-90% arise from the adrenal medulla, the remainder occur in extra-adrenal sites (Paragangliomas), most commonly at the organ of Zuckerkandl (near the aortic bifurcation). * Option C: These tumors secrete catecholamines (primarily norepinephrine and epinephrine), leading to the classic triad of episodic headache, sweating, and tachycardia. * Option D: Extra-adrenal pheochromocytomas (paragangliomas) arise from sympathetic ganglia (along the sympathetic chain) or parasympathetic ganglia (e.g., carotid body). Clinical Pearls for NEET-PG: * The Rule of 10s: 10% Bilateral, 10% Extra-adrenal, 10% Malignant, 10% Pediatric, and 10% Familial (though genetic links are now known to be closer to 30-40%). * Diagnosis: Best initial screening test is 24-hour urinary fractionated metanephrines or plasma free metanephrines. * Pre-op Management: Always give Alpha-blockers first (e.g., Phenoxybenzamine) followed by Beta-blockers to avoid a hypertensive crisis. * Associated Syndromes: MEN 2A, MEN 2B, von Hippel-Lindau (VHL), and Neurofibromatosis type 1 (NF1).
Question 137: A patient with an endocrine abnormality shows a 'hung up' reflex. Which of the following conditions causes a 'hung up' reflex?
- A. Myxedema
- B. Hyperthyroidism
- C. Hypothyroidism (Correct Answer)
- D. Pheochromocytoma
Explanation: ### Explanation **Correct Answer: C. Hypothyroidism** The **'hung up' reflex** (also known as Woltman’s sign) refers to a delayed relaxation phase of the deep tendon reflexes, most commonly observed in the Achilles tendon (ankle jerk). **Underlying Pathophysiology:** In hypothyroidism, the slowed relaxation is not due to a defect in nerve conduction, but rather a **mechanical delay in the muscle fibers**. Low levels of thyroid hormone lead to: 1. Decreased activity of the **calcium-ATPase pump** (SERCA) in the sarcoplasmic reticulum, which slows the reuptake of calcium required for muscle relaxation. 2. Changes in myosin isoform expression and slowed ATP turnover. **Analysis of Incorrect Options:** * **A. Myxedema:** While myxedema is a severe form of hypothyroidism, the term "Hypothyroidism" (Option C) is the broader, standard clinical diagnosis associated with this sign [1]. In many exams, if both are present, the primary disease state is preferred. * **B. Hyperthyroidism:** This condition typically presents with **brisk or hyperreflexic** deep tendon reflexes due to increased neuromuscular excitability. * **D. Pheochromocytoma:** This catecholamine-secreting tumor causes hypertension and tachycardia; it does not typically affect the relaxation phase of reflexes [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Woltman’s Sign:** Specifically refers to the delayed relaxation in hypothyroidism. * **Differential Diagnosis for Delayed Relaxation:** Besides hypothyroidism, it can be seen in anorexia nervosa, hypothermia, diabetes mellitus (rarely), and with certain drugs like beta-blockers. * **Pendular Knee Jerk:** Contrast this with the "hung up" reflex; pendular jerks are characteristic of **cerebellar lesions**. * **Pseudomyotonia:** Another term sometimes used to describe the slow relaxation phase in hypothyroid patients.
Question 138: Increased anion gap is a characteristic feature of which condition?
- A. Hyperosmolar non-ketotic diabetic coma
- B. Hypoglycaemic coma
- C. Phenformin toxicity with coma (Correct Answer)
- D. Renal tubular acidosis
Explanation: **Explanation:** The **Anion Gap (AG)** is calculated as $[Na^+] - ([Cl^-] + [HCO_3^-])$. An increased anion gap indicates the presence of unmeasured metabolic acids in the blood [1]. **Why Option C is Correct:** **Phenformin** (a biguanide similar to metformin, but with a much higher risk profile) causes **Lactic Acidosis**. It interferes with mitochondrial oxidative phosphorylation and inhibits gluconeogenesis, leading to the accumulation of lactate [1]. Since lactate is an unmeasured anion, it replaces bicarbonate, resulting in a **High Anion Gap Metabolic Acidosis (HAGMA)**. **Analysis of Incorrect Options:** * **A. Hyperosmolar Non-Ketotic Coma (HONK/HHS):** Characterized by extreme hyperglycemia and hyperosmolarity without significant ketone production. Because there is enough insulin to prevent lipolysis, ketoacids do not accumulate; thus, the anion gap is typically normal or only minimally elevated. * **B. Hypoglycaemic Coma:** This is a metabolic emergency due to low fuel substrate for the brain. It does not inherently involve the accumulation of organic acids, so the anion gap remains normal. * **D. Renal Tubular Acidosis (RTA):** This is a classic cause of **Normal Anion Gap Metabolic Acidosis (NAGMA)** or hyperchloremic acidosis [1]. The drop in bicarbonate is compensated for by a proportional increase in chloride. **NEET-PG High-Yield Pearls:** * **Mnemonic for HAGMA:** **MUDPILES** (Methanol, Uremia, DKA, Propylene glycol, Iron/INH, **Lactic acidosis**, Ethylene glycol, Salicylates). * **Mnemonic for NAGMA:** **HARDUP** (Hyperalimentation, Acetazolamide, **RTA**, Diarrhea, Uretero-sigmoidostomy, Pancreatic fistula). * **Clinical Note:** Phenformin was withdrawn in many countries due to this specific risk of fatal lactic acidosis; Metformin carries a much lower risk but is still contraindicated in severe renal failure [1].
Question 139: What is the most common presentation of Multiple Endocrine Neoplasia type 1 (MEN I)?
- A. Primary hyperparathyroidism (Correct Answer)
- B. Hyperprolactinemia
- C. Hypergastrinemia
- D. Acromegaly
Explanation: **Explanation:** **Multiple Endocrine Neoplasia type 1 (MEN 1)**, also known as Wermer’s syndrome, is an autosomal dominant disorder caused by a mutation in the *MEN1* gene (encoding the protein Menin). It is classically characterized by the **"3 Ps"**: **P**arathyroid, **P**ancreas, and **P**ituitary tumors. 1. **Why Primary Hyperparathyroidism is correct:** Primary hyperparathyroidism (PHPT) is the **most common** (occurring in >95% of patients) and usually the **earliest** clinical manifestation of MEN 1. Unlike sporadic cases, PHPT in MEN 1 typically involves multiglandular hyperplasia rather than a single adenoma, often presenting between the ages of 20 and 25. 2. **Why the other options are incorrect:** * **B. Hyperprolactinemia:** Pituitary adenomas occur in about 30–40% of MEN 1 patients. While a prolactinoma is the most common pituitary tumor in this syndrome, it occurs less frequently than hyperparathyroidism. * **C. Hypergastrinemia:** Pancreatic neuroendocrine tumors (NETs) occur in 30–70% of patients. Gastrinomas (causing Zollinger-Ellison Syndrome) are the most common symptomatic pancreatic NETs, but they are still less prevalent than parathyroid involvement. * **D. Acromegaly:** This results from growth hormone-secreting pituitary tumors, which occur in less than 10% of MEN 1 cases. **High-Yield Clinical Pearls for NEET-PG:** * **Screening:** The first biochemical sign of MEN 1 is often an elevated serum calcium or PTH level. * **Order of frequency:** Parathyroid (>95%) > Pancreatic NETs (30-70%) > Pituitary (30-40%). * **Gastrinoma location:** In MEN 1, gastrinomas are more commonly found in the **duodenum** than the pancreas. * **Associated tumors:** Adrenal cortical tumors, facial angiofibromas, collagenomas, and lipomas are also seen in MEN 1.
Question 140: Which of the following conditions causes hypercalcemia with a normal or low parathyroid hormone (PTH) level?
- A. Parathyroid adenoma
- B. Familial hypocalciuric hypercalcemia
- C. Parathyroid hyperplasia
- D. Sarcoidosis (Correct Answer)
Explanation: ### Explanation The key to solving this question lies in understanding the **feedback loop** between serum calcium and Parathyroid Hormone (PTH). In a normal physiological state, hypercalcemia should suppress PTH secretion [2]. **1. Why Sarcoidosis is Correct:** Sarcoidosis is a granulomatous disease. Macrophages within the granulomas contain the enzyme **1-alpha-hydroxylase**, which independently converts 25-hydroxyvitamin D into its active form, **1,25-dihydroxyvitamin D (Calcitriol)**. This leads to increased intestinal calcium absorption [2]. The resulting hypercalcemia appropriately **suppresses the parathyroid glands**, leading to low or low-normal PTH levels (PTH-independent hypercalcemia) [2]. **2. Why the Other Options are Incorrect:** * **A & C (Parathyroid Adenoma/Hyperplasia):** These are causes of **Primary Hyperparathyroidism** [1]. Here, the pathology lies within the parathyroid gland itself, which autonomously secretes high levels of PTH despite elevated serum calcium [1]. * **B (Familial Hypocalciuric Hypercalcemia - FHH):** This is caused by an inactivating mutation in the **Calcium-Sensing Receptor (CaSR)** [1]. The parathyroid glands "perceive" normal calcium levels as low, leading to inappropriately **normal or mildly elevated PTH** levels in the presence of hypercalcemia [2]. **3. High-Yield Clinical Pearls for NEET-PG:** * **PTH-Independent Hypercalcemia (Low PTH):** Think of Malignancy (PTHrP), Sarcoidosis/Tuberculosis (Vitamin D mediated), Multiple Myeloma, and Vitamin D toxicity [2]. * **PTH-Dependent Hypercalcemia (High/Normal PTH):** Think of Primary Hyperparathyroidism and FHH [2]. * **Distinguishing FHH from Primary Hyperparathyroidism:** FHH presents with a **Urinary Calcium/Creatinine Clearance Ratio < 0.01**, whereas it is > 0.02 in Primary Hyperparathyroidism. * **Sarcoidosis Triad:** Bilateral hilar lymphadenopathy, hypercalcemia, and elevated ACE (Angiotensin-Converting Enzyme) levels.
Practice by Chapter
Diabetes Mellitus
Practice Questions
Thyroid Disorders
Practice Questions
Adrenal Gland Disorders
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Pituitary Disorders
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Calcium and Bone Metabolism
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Reproductive Endocrinology
Practice Questions
Lipid Disorders
Practice Questions
Endocrine Hypertension
Practice Questions
Multiple Endocrine Neoplasia
Practice Questions
Obesity and Metabolic Syndrome
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Neuroendocrine Tumors
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Endocrine Emergencies
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