Endocrinology Practice Questions

Q: Which of the following is NOT a cause of hypopituitarism?

Acidophilic tumor. **Explanation:** Hypopituitarism refers to the deficiency of one or more pituitary hormones, usually resulting from the destruction of the anterior pituitary gland [3]. **Why "Acidophilic tumor" is the correct answer:** Acidophilic tumors (also known as somatotroph adenomas) are **functioning adenomas**. They are characterized by the hypersecretion of Growth Hormone (GH), leading to Gigantism (in children) or Acromegaly (in adults). Because these tumors cause a **hyperstate** (excess hormone production) rather than a deficiency, they are not a cause of hypopituitarism. **Analysis of Incorrect Options:** * **Breast and Bronchus Cancer (A & B):** The pituitary gland is a common site for hematogenous metastasis. Breast and lung (bronchus) cancers are the most frequent primary malignancies that metastasize to the pituitary. These metastatic deposits destroy the normal pituitary parenchyma, leading to hypopituitarism and Diabetes Insipidus. * **Chromophilic Adenoma (C):** While the term is older, it refers to tumors that stain with dyes. Large, non-functioning chromophobe adenomas are the most common cause of hypopituitarism in adults because they compress the normal pituitary tissue and the pituitary stalk (mass effect) [2]. **NEET-PG High-Yield Pearls:** 1. **Most common cause of hypopituitarism:** Non-functioning pituitary adenomas (due to compression) [2]. 2. **Sheehan Syndrome:** Ischemic necrosis of the pituitary post-partum; the first clinical sign is usually failure to lactate [1]. 3. **Empty Sella Syndrome:** Can be primary (arachnoid herniation) or secondary (post-surgery/radiation), potentially leading to hormone deficiencies [1]. 4. **Order of hormone loss:** GH → LH/FSH → TSH → ACTH (mnemonic: **"Go Look For The Adenoma"**).

Q: Atrial fibrillation is common in which of the following conditions?

Hyperthyroidism. **Hyperthyroidism** is the correct answer because thyroid hormones (T3 and T4) have direct and indirect stimulatory effects on the cardiovascular system [1]. Excess thyroid hormone increases the expression of beta-adrenergic receptors in the myocardium, leading to a state of hyper-adrenergic sensitivity [4]. This results in increased heart rate (tachycardia), increased stroke volume, and shortened refractory periods of the atrial cardiomyocytes. These electrophysiological changes create a substrate for reentry, making **Atrial Fibrillation (AF)** the most common sustained arrhythmia in hyperthyroid patients (occurring in 10–15% of cases) [1], [3]. **Why other options are incorrect:** * **Adrenogenital Syndrome (CAH):** This involves enzyme deficiencies (like 21-hydroxylase) leading to cortisol deficiency and androgen excess. It typically presents with virilization or salt-wasting, not tachyarrhythmias. * **Addison’s Disease:** Primary adrenal insufficiency leads to hypotension and hyperkalemia. While severe hyperkalemia can cause peaked T-waves or bradycardia, AF is not a characteristic feature. * **Von-Willebrand’s Disease:** This is a qualitative or quantitative deficiency of Von-Willebrand factor leading to a bleeding diathesis. It has no direct pathophysiological link to cardiac rhythm disturbances. **Clinical Pearls for NEET-PG:** * **Apathetic Hyperthyroidism:** In elderly patients, AF may be the *only* presenting sign of hyperthyroidism [1]. * **Subclinical Hyperthyroidism:** Even a suppressed TSH with normal T3/T4 levels is a recognized risk factor for developing AF. * **Treatment:** In thyrotoxic AF, **Beta-blockers** (e.g., Propranolol) are the first-line treatment to control heart rate and inhibit the peripheral conversion of T4 to T3 [2]. Normal sinus rhythm often restores spontaneously once the patient becomes euthyroid.

Q: The syndrome of inappropriate antidiuretic hormone (SIADH) is characterized by which of the following?

Hyponatremia and urine sodium excretion > 20 mEq/L. **Explanation:** The Syndrome of Inappropriate Antidiuretic Hormone (SIADH) is a condition characterized by the excessive release of ADH (vasopressin) from the posterior pituitary or ectopic sources, regardless of serum osmolality. **1. Why Option A is Correct:** The core pathophysiology involves excessive water reabsorption in the collecting ducts [1], leading to **euvolemic hyponatremia** (dilutional) [2]. Despite the low serum sodium, the body’s volume-sensing mechanisms (atrial natriuretic peptide) are activated due to transient subclinical volume expansion. This leads to **natriuresis** (increased urinary sodium excretion, typically **> 20–40 mEq/L**) and inappropriately concentrated urine (Urine Osmolality > 100 mOsm/kg). **2. Why Other Options are Incorrect:** * **Options B & D:** SIADH is fundamentally a hyponatremic state. Hypernatremia is seen in conditions like Diabetes Insipidus, where there is a deficiency or resistance to ADH. * **Option C:** While hyponatremia is present, SIADH does not typically affect potassium levels. Hyperkalemia associated with hyponatremia is a hallmark of **Adrenal Insufficiency (Addison’s Disease)**, which must be ruled out before diagnosing SIADH. **Clinical Pearls for NEET-PG:** * **Diagnostic Criteria:** Hyponatremia, low serum osmolality ( 100 mOsm/kg), and clinical euvolemia [2]. * **Common Causes:** Small cell carcinoma of the lung (ectopic), CNS disorders (stroke, trauma), and drugs (SSRIs, Carbamazepine, Cyclophosphamide). * **Management:** Fluid restriction is the first-line treatment. For severe/symptomatic cases, hypertonic saline (3%) is used. **Vaptans** (Tolvaptan) are vasopressin receptor antagonists used in chronic cases [3]. * **Caution:** Rapid correction of hyponatremia can lead to **Osmotic Demyelination Syndrome (Central Pontine Myelinolysis).**

Q: Which treatment is contraindicated in hypophosphatasia?

Vitamin D. **Explanation:** **Hypophosphatasia (HPP)** is a rare genetic disorder caused by a loss-of-function mutation in the **ALPL gene**, which encodes **Tissue-Nonspecific Alkaline Phosphatase (TNSALP)**. This deficiency leads to an accumulation of inorganic pyrophosphate (PPi), a potent inhibitor of mineralization. **Why Vitamin D is Contraindicated:** In HPP, patients typically present with **hypercalcemia** and **hypercalciuria** because calcium cannot be deposited into the bone matrix due to the lack of alkaline phosphatase. Administering **Vitamin D** (Option A) increases intestinal calcium absorption and bone resorption, which severely exacerbates hypercalcemia and hypercalciuria. This can lead to nephrocalcinosis, renal failure, and vitamin D toxicity. Therefore, Vitamin D and calcium supplements are strictly contraindicated unless a co-existing deficiency is proven. **Analysis of Other Options:** * **Calcium chelating agents (Option B):** These are not standard treatments but are not contraindicated; in cases of severe hypercalcemic crisis, they may be used to lower serum calcium. * **Enzyme Replacement (Option C):** **Asfotase alfa** is the definitive, FDA-approved treatment for HPP. It is a recombinant TNSALP that improves mineralization and survival. * **Renal Dialysis (Option D):** While not a primary treatment for HPP, it may be required if the patient develops end-stage renal disease due to chronic nephrocalcinosis. **NEET-PG High-Yield Pearls:** * **Biochemical Hallmark:** Low serum Alkaline Phosphatase (ALP) levels (age-adjusted) and elevated serum Pyridoxal-5'-Phosphate (Vitamin B6). * **Clinical Sign:** Premature loss of deciduous teeth (before age 5) is a classic pediatric presentation. * **Radiology:** "Copper beaten skull" (craniosynostosis) and metaphyseal lucencies (resembling rickets).

Q: Which of the following is true about MEN-I?

Hyperprolactinemia. **Explanation:** Multiple Endocrine Neoplasia Type I (MEN-I), 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. **Why Hyperprolactinemia is Correct:** Pituitary adenomas occur in approximately 30–40% of MEN-I patients. Among these, **Prolactinoma** is the most common functional pituitary tumor. Therefore, elevated prolactin levels (hyperprolactinemia) are a hallmark clinical finding in these patients. **Analysis of Incorrect Options:** * **A. Increased VMA in urine:** Vanillylmandelic acid (VMA) is a metabolite of catecholamines. Increased VMA is seen in **Pheochromocytoma**, which is a feature of **MEN-2A and 2B**, not MEN-1. * **B. Increased Calcitonin:** Elevated calcitonin is a marker for **Medullary Thyroid Carcinoma (MTC)**. MTC is a defining component of **MEN-2A and 2B**. * **C. Hypergastrinemia:** While Gastrinomas (Zollinger-Ellison Syndrome) are the most common functional pancreatic neuroendocrine tumors in MEN-I, **Hyperprolactinemia** is considered a more direct "classic" answer in many competitive exams when distinguishing between the MEN syndromes, as pituitary involvement is unique to MEN-1. (Note: In some clinical contexts, both C and D could occur, but Prolactinoma remains the most frequent pituitary lesion). **NEET-PG High-Yield Pearls:** * **Most common presentation of MEN-I:** Primary Hyperparathyroidism (seen in >95% of patients). * **Most common Pancreatic tumor in MEN-I:** Gastrinoma (though non-functional tumors are also frequent). * **MEN-2A (Sipple Syndrome):** Medullary Thyroid CA + Pheochromocytoma + Parathyroid Hyperplasia. * **MEN-2B:** Medullary Thyroid CA + Pheochromocytoma + Mucosal Neuromas + Marfanoid Habitus.

Q: Shortening of the 4th metacarpal is a feature of which condition?

Pseudohypoparathyroidism. The shortening of the 4th metacarpal (and often the 5th) is a classic clinical sign known as **Archibald’s sign**. This occurs due to premature closure of the epiphyses. **1. Why Pseudohypoparathyroidism (PHP) is correct:** PHP is characterized by end-organ resistance to Parathyroid Hormone (PTH). Specifically, **PHP Type 1a** is associated with a constellation of physical findings known as **Albright’s Hereditary Osteodystrophy (AHO)**. The hallmark features of AHO include short stature, round facies, obesity, subcutaneous calcifications, and **brachydactyly** (shortening of the 4th and 5th metacarpals) [1]. When you ask the patient to make a fist, the 4th knuckle appears as a dimple rather than a prominence (Knuckle-Knuckle-Dimple-Dimple sign). **2. Why other options are incorrect:** * **Hyperparathyroidism:** This condition is characterized by excessive PTH, leading to bone resorption. The classic radiological finding is **subperiosteal bone resorption**, most commonly seen on the radial aspect of the middle phalanges, not shortening of the metacarpals. * **Hypoparathyroidism:** This involves a deficiency of PTH. While it causes hypocalcemia and hyperphosphatemia, it does not typically present with the skeletal deformities (AHO) seen in PHP. * **Scleroderma:** This is a connective tissue disorder. While it can cause **acro-osteolysis** (resorption of the distal phalangeal tufts) leading to shortened fingertips, it does not cause congenital shortening of the metacarpals. **Clinical Pearls for NEET-PG:** * **Pseudopseudohypoparathyroidism (PPHP):** Patients have the physical features of AHO (including the short 4th metacarpal) but have **normal** calcium and PTH levels [1]. * **Genetics:** PHP Type 1a is caused by a mutation in the *GNAS1* gene and is inherited from the mother (Genomic Imprinting) [1]. * **Differential for short 4th metacarpal:** Turner Syndrome, PHP/PPHP, and occasionally Down Syndrome.

Question 1

A 35-year-old man has fasting and postprandial blood sugar within normal limits, but urine sugar is 3 plus (+++). What is the diagnosis?

Accepted Answer

Renal glycosuria

Answer

Pancreatic insufficiency

Answer

Alimentary glycosuria

Answer

High carbohydrate diet taken in the morning

Question 2

A 18-year-old male presents with severe weakness, dizziness, sleepiness, unquenchable thirst, and increased urination over the past 4 weeks. He has also experienced drowsiness and generalized tiredness in a previous episode 3 weeks earlier and has lost 4kg of weight. Laboratory findings on admission show a glucose of 560 mg/dl, urine that is 4+ for glucose and has "large" acetone, and an HbA1c of 14%. Which of the following is true regarding this patient?

Accepted Answer

Increased lipolysis

Answer

Increased glucose uptake

Answer

Decreased hepatic glucose output

Answer

Decreased protein catabolism

Question 3

Which of the following is NOT a cause of hypopituitarism?

Accepted Answer

Acidophilic tumor

Answer

Breast cancer

Answer

Bronchus cancer

Answer

Chromophilic adenoma

Question 4

High calcium uptake leads to which of the following conditions?

Accepted Answer

Milk alkali syndrome

Answer

Osteopoikilosis

Answer

Osteopetrosis

Answer

Cardiomyopathy

Question 5

Atrial fibrillation is common in which of the following conditions?

Accepted Answer

Hyperthyroidism

Answer

Adrenogenital syndrome

Answer

Addison's disease

Answer

Von-Willebrand's disease

Question 6

The syndrome of inappropriate antidiuretic hormone (SIADH) is characterized by which of the following?

Accepted Answer

Hyponatremia and urine sodium excretion > 20 mEq/L

Answer

Hypernatremia and urine sodium excretion > 20 mEq/L

Answer

Hyponatremia and hyperkalemia

Answer

Hypernatremia and hypokalemia

Question 7

Which treatment is contraindicated in hypophosphatasia?

Accepted Answer

Vitamin D

Answer

Calcium chelating agent

Answer

Enzyme replacement

Answer

Renal dialysis

Question 8

Which of the following is true about MEN-I?

Accepted Answer

Hyperprolactinemia

Answer

Increased VMA in urine

Answer

Increased Calcitonin

Answer

Hypergastrinemia

Question 9

Which of the following is a diagnostic criterion of Metabolic syndrome?

Accepted Answer

High serum triglyceride

Answer

High serum homocysteine

Answer

High serum adiponectin

Answer

Low HDL cholesterol

Question 10

Shortening of the 4th metacarpal is a feature of which condition?

Accepted Answer

Pseudohypoparathyroidism

Answer

Hyperparathyroidism

Answer

Hyperparathyroidism

Answer

Scleroderma

Endocrinology — MCQs

Endocrinology — MCQs

On this page

Practice by Chapter

Want unlimited practice?