Endocrinology — MCQs
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A 40-year-old patient presented with excessive skin pigmentation of the face, neck, and extensor aspects of the forearms. The patient has diabetes, anhidrosis, and dyspnea on exertion (Class III). Clinical examination revealed hepatosplenomegaly and spider angiomata. Which of the following is NOT true about this condition?
Which of the following conditions can lead to the development of SIADH?
Which of the following conditions does NOT cause weight gain?
L-thyroxine can be given safely in cases of which of the following conditions?
Which of the following is the most common type of pituitary adenoma?
Which of the following is true regarding diabetes mellitus type II?
Which HLA antigen is important in Insulin-Dependent Diabetes Mellitus (IDDM)?
A 49-year-old male schoolteacher presents with a neck swelling that has a palpable bounding pulse. Which test would be most likely to establish a possible cause of the underlying condition?
Which of the following is NOT a risk factor for type 2 diabetes mellitus that warrants early screening for diabetes?
Males who are sexually underdeveloped with rudimentary testes and prostate glands, sparse pubic and facial hair, long arms and legs, and large hands and feet are likely to have which chromosome complement?
Endocrinology Indian Medical PG Practice Questions and MCQs
Question 501: A 40-year-old patient presented with excessive skin pigmentation of the face, neck, and extensor aspects of the forearms. The patient has diabetes, anhidrosis, and dyspnea on exertion (Class III). Clinical examination revealed hepatosplenomegaly and spider angiomata. Which of the following is NOT true about this condition?
- A. It is caused by a mutant gene termed HFE.
- B. The risk of hepatocellular carcinoma is very high.
- C. Females are commonly affected. (Correct Answer)
- D. The most common cardiac manifestation is congestive cardiac failure (CCF).
Explanation: The clinical presentation of **Bronze Diabetes** (skin pigmentation, diabetes, and hepatosplenomegaly) combined with cardiac failure and anhidrosis strongly points to a diagnosis of **Hereditary Hemochromatosis (HH)** [1]. ### **Explanation of Options** * **Why Option C is NOT true (Correct Answer):** Hereditary Hemochromatosis is an autosomal recessive disorder, but it shows a **marked male predominance** (approx. 10:1). Females are protected during their reproductive years because physiological iron loss through **menstruation and pregnancy** prevents the toxic accumulation of iron. Clinical symptoms in women typically appear only after menopause. * **Option A is true:** The most common form of HH is caused by a mutation in the **HFE gene** (specifically the C282Y mutation) [2] on chromosome 6 [1], leading to increased intestinal iron absorption. * **Option B is true:** Patients with HH and cirrhosis have a significantly elevated risk (up to 200-fold) of developing **Hepatocellular Carcinoma (HCC)** [1]. It is a leading cause of death in these patients. * **Option D is true:** Iron deposition in the myocardium leads to restrictive or dilated cardiomyopathy. **Congestive Cardiac Failure (CCF)** and arrhythmias are the most common cardiac manifestations. ### **High-Yield Clinical Pearls for NEET-PG** * **Classic Triad:** Cirrhosis, Diabetes Mellitus, and Skin Pigmentation ("Bronze Diabetes") [1]. * **Earliest Sign:** Arthropathy (typically involving the 2nd and 3rd metacarpophalangeal joints). * **Screening:** The best initial test is **Transferrin Saturation** (>45% is suggestive). * **Gold Standard Diagnosis:** Liver biopsy with Perl’s Prussian blue stain (to calculate the Hepatic Iron Index) or MRI (T2* weighted) [2]. * **Treatment of Choice:** Therapeutic Phlebotomy (Goal: Serum ferritin 50–100 ng/mL) [2].
Question 502: Which of the following conditions can lead to the development of SIADH?
- A. Head trauma (Correct Answer)
- B. Pituitary adenoma
- C. Lithium
- D. All of the above
Explanation: **Explanation:** **SIADH (Syndrome of Inappropriate Antidiuretic Hormone)** occurs when there is an autonomous, excessive release of ADH from the posterior pituitary or an ectopic source, leading to water retention and dilutional hyponatremia [1]. 1. **Why Head Trauma is Correct:** Central Nervous System (CNS) disorders are a major cause of SIADH. Any insult to the brain—including **head trauma**, stroke, meningitis, or tumors—disrupts the normal osmoreceptor-mediated regulation of ADH, leading to its persistent release despite low plasma osmolality [3]. 2. **Why Other Options are Incorrect:** * **Pituitary Adenoma:** These typically cause hormone deficiencies (hypopituitarism) or hypersecretion of anterior pituitary hormones (e.g., Prolactin, GH). They do not typically cause SIADH; in fact, damage to the pituitary stalk or posterior pituitary more commonly leads to **Diabetes Insipidus (DI)**, the functional opposite of SIADH [3]. * **Lithium:** This is a classic cause of **Nephrogenic Diabetes Insipidus**. It renders the collecting ducts resistant to ADH, leading to polyuria and hypernatremia, rather than the water retention seen in SIADH. **High-Yield Clinical Pearls for NEET-PG:** * **Ectopic Source:** Small Cell Carcinoma of the Lung is the most common malignancy associated with SIADH [2]. * **Drugs:** Common culprits include SSRIs, Carbamazepine, and Cyclophosphamide. * **Diagnosis:** Characterized by **Euvolemic Hyponatremia**, low serum osmolality (<275 mOsm/kg), and inappropriately high urine osmolality (>100 mOsm/kg). * **Treatment:** Fluid restriction is the first-line therapy. For severe cases, Vaptans (ADH antagonists) or hypertonic saline may be used. Always correct sodium slowly to avoid **Osmotic Demyelination Syndrome (Central Pontine Myelinolysis).**
Question 503: Which of the following conditions does NOT cause weight gain?
- A. Diabetes mellitus (Correct Answer)
- B. Cushing's syndrome
- C. Hypothyroidism
- D. Insulin secreting tumour
Explanation: **Explanation:** The correct answer is **Diabetes Mellitus (Option A)**. In untreated or poorly controlled diabetes mellitus (particularly Type 1), there is either an absolute or relative deficiency of insulin. Insulin is a potent anabolic hormone; without its action, the body cannot utilize glucose for energy and instead enters a catabolic state [1]. This leads to the breakdown of stored fats (lipolysis) and proteins (proteolysis), resulting in **weight loss** despite polyphagia (increased appetite) [1]. **Analysis of Incorrect Options:** * **Cushing’s Syndrome:** Characterized by hypercortisolism, which promotes gluconeogenesis and adipogenesis. It causes weight gain with a classic "centripetal" distribution (moon facies, buffalo hump, and truncal obesity) [2]. * **Hypothyroidism:** A deficiency in thyroid hormones leads to a decrease in the Basal Metabolic Rate (BMR). Weight gain occurs due to both fat accumulation and the deposition of glycosaminoglycans, which causes water retention (myxedema). * **Insulin-secreting tumor (Insulinoma):** Excessive insulin secretion promotes lipogenesis and inhibits lipolysis. Furthermore, patients often overeat to prevent or treat recurrent episodes of symptomatic hypoglycemia, leading to significant weight gain. **High-Yield Clinical Pearls for NEET-PG:** * **Weight Loss in DM:** The "3 Ps" of Diabetes are Polyuria, Polydipsia, and Polyphagia, but these are paradoxically accompanied by weight loss [2]. * **Drug-Induced Weight Gain:** Common culprits include Sulfonylureas, Thiazolidinediones (TZDs), Steroids, and Antipsychotics. * **Weight-Neutral/Loss DM Drugs:** Metformin and DPP-4 inhibitors are weight-neutral; SGLT-2 inhibitors and GLP-1 agonists promote weight loss.
Question 504: L-thyroxine can be given safely in cases of which of the following conditions?
- A. Hypothyroidism (Correct Answer)
- B. Hyperthyroidism
- C. Hashimoto's disease
- D. Graves' disease
Explanation: L-thyroxine (Levothyroxine) is a synthetic form of the thyroid hormone thyroxine (T4). It is the standard of care for hormone replacement therapy in patients with deficient thyroid function. [1] 1. Why Hypothyroidism is the Correct Answer: In Hypothyroidism, the thyroid gland fails to produce sufficient levels of T3 and T4. This leads to a systemic slowing of metabolic processes. Administering L-thyroxine restores physiological hormone levels, normalizes the Serum TSH, and alleviates symptoms like fatigue, weight gain, and bradycardia. [1] It is safe and essential for long-term management. 2. Why the Other Options are Incorrect: * Hyperthyroidism (Option B): This condition is characterized by an excess of thyroid hormones. Giving L-thyroxine would exacerbate the thyrotoxicosis, leading to dangerous complications like cardiac arrhythmias, hypertension, and thyroid storm. * Graves’ Disease (Option D): This is an autoimmune form of hyperthyroidism caused by TSH-receptor antibodies (TRAb). Since the patient is already in a hypermetabolic state, L-thyroxine is contraindicated unless the patient has been rendered hypothyroid post-surgery or radioactive iodine therapy. * Hashimoto’s Disease (Option C): While Hashimoto’s is the most common cause of hypothyroidism, the disease itself is an autoimmune inflammatory process. In its early stages (Hashitoxicosis), patients may actually be hyperthyroid due to the release of stored hormones from follicular destruction. Therefore, L-thyroxine is only given during the hypothyroid phase of the disease [1], making "Hypothyroidism" the more precise and universally safe clinical indication. High-Yield Clinical Pearls for NEET-PG: * Monitoring: The best marker for monitoring L-thyroxine efficacy in primary hypothyroidism is Serum TSH. [1] * Administration: It should be taken on an empty stomach (30–60 minutes before breakfast) as calcium, iron, and coffee can significantly impair absorption. [1] * Ischemic Heart Disease: In elderly patients or those with known CAD, start with a low dose ("Start low, go slow") to avoid precipitating myocardial infarction due to increased metabolic demand. [1]
Question 505: Which of the following is the most common type of pituitary adenoma?
- A. Thyrotropinoma
- B. Gonadotropinoma
- C. Prolactinoma (Correct Answer)
- D. Corticotropinoma
Explanation: Pituitary adenomas are common benign neoplasms of the anterior pituitary gland. They are classified based on their size (microadenomas <10 mm; macroadenomas >10 mm) and their functional status (hormone-secreting vs. non-functional) [1]. **Why Prolactinoma is correct:** **Prolactinomas** are the most common type of secretory pituitary adenoma, accounting for approximately **40–50%** of all pituitary tumors [1]. They typically present with symptoms of hyperprolactinemia, such as galactorrhea, amenorrhea, and infertility in women, or decreased libido and erectile dysfunction in men [1]. **Analysis of Incorrect Options:** * **Thyrotropinoma (TSH-secreting):** These are the rarest type of pituitary adenomas (<1%). They present with features of secondary hyperthyroidism (elevated T3/T4 with inappropriately normal or high TSH). * **Gonadotropinoma (LH/FSH-secreting):** While common among "non-functioning" adenomas (as they often secrete inefficiently), they are significantly less frequent than prolactinomas. * **Corticotropinoma (ACTH-secreting):** These account for about 10–15% of pituitary adenomas and lead to **Cushing’s Disease**. They are usually microadenomas at the time of diagnosis. **NEET-PG High-Yield Pearls:** 1. **Order of frequency:** Prolactinoma > Somatotropinoma (GH) > Corticotropinoma (ACTH). 2. **Drug of Choice:** For most pituitary adenomas, surgery (transsphenoidal) is the first line. However, for **Prolactinomas**, medical management with **Dopamine agonists (Cabergoline/Bromocriptine)** is the first-line treatment [1]. 3. **MEN 1 Syndrome:** Pituitary adenomas (most commonly prolactinomas) are a classic component of the "3 Ps" (Pituitary, Parathyroid, Pancreas).
Question 506: Which of the following is true regarding diabetes mellitus type II?
- A. Insulinitis of B cells
- B. Hyalinization of B cells
- C. Atrophy of B cells
- D. Decrease in the number of B cells (Correct Answer)
Explanation: Explanation: In Diabetes Mellitus Type II (T2DM), the pathophysiology is characterized by a combination of peripheral insulin resistance and progressive beta-cell (B-cell) dysfunction [1]. While T2DM is initially associated with hyperinsulinemia to compensate for resistance, the chronic metabolic stress (glucotoxicity and lipotoxicity) eventually leads to B-cell exhaustion [2]. Histologically, this manifests as a decrease in the total number (mass) of B-cells, typically reduced by 40–60% in long-standing cases [1]. Analysis of Options: * A. Insulinitis of B cells: This is a hallmark of Type I Diabetes [3]. It refers to lymphocytic infiltration of the islets, representing an autoimmune destruction of B-cells [4]. * B. Hyalinization of B cells: While amyloid (amylin) deposition (which appears as hyalinization) is a classic finding in the islets of T2DM patients, the term "hyalinization of B-cells" is technically inaccurate. Hyalinization occurs in the extracellular space of the islets, not within the cells themselves. * C. Atrophy of B cells: Atrophy implies a reduction in the size of existing cells. In T2DM, the primary pathology is the apoptosis and loss of the cells, leading to a decrease in total number rather than simple cellular atrophy [1]. * D. Decrease in the number of B cells: This is the most accurate description of the quantitative loss of insulin-producing capacity in T2DM [1]. NEET-PG High-Yield Pearls: * Amyloid Deposition: The characteristic histological finding in T2DM islets is the deposition of Islet Amyloid Polypeptide (IAPP) or Amylin. * HLA Association: T2DM has no strong association with HLA-DR3/DR4 (unlike T1DM) [3]. * Genetics: T2DM has a higher genetic concordance in monozygotic twins (>90%) compared to T1DM (~50%) [3]. * Metabolic Syndrome: T2DM is frequently associated with the "Deadly Quartet": obesity, hypertension, dyslipidemia, and hyperglycemia [4].
Question 507: Which HLA antigen is important in Insulin-Dependent Diabetes Mellitus (IDDM)?
- A. HLA-A3
- B. HLA-B27
- C. HLA-DR3/DR4 (Correct Answer)
- D. HLA-W1
Explanation: **Explanation:** **Correct Answer: C. HLA-DR3/DR4** Insulin-Dependent Diabetes Mellitus (Type 1 DM) is an autoimmune disorder characterized by the destruction of pancreatic beta cells [1][2]. Susceptibility to T1DM is strongly linked to the **Major Histocompatibility Complex (MHC) Class II** genes located on chromosome 6 [2]. Specifically, **HLA-DR3** and **HLA-DR4** are the most significant genetic risk factors. * Approximately 90-95% of Type 1 DM patients carry HLA-DR3, DR4, or both (heterozygotes for DR3/DR4 have the highest risk). * These alleles influence the presentation of islet autoantigens to T-lymphocytes, triggering the autoimmune cascade [1]. **Analysis of Incorrect Options:** * **A. HLA-A3:** This is associated with **Hereditary Hemochromatosis**. (Mnemonic: "A3" for "Iron" - both have 3/tri- associations). * **B. HLA-B27:** This is a Class I MHC allele strongly associated with **Seronegative Spondyloarthropathies**, such as Ankylosing Spondylitis, Reiter’s Syndrome (Reactive Arthritis), and Psoriatic Arthritis. * **D. HLA-W1:** This is an obsolete nomenclature and is not a recognized high-yield association for endocrine disorders in the NEET-PG curriculum. **High-Yield Clinical Pearls for NEET-PG:** * **HLA-DQ:** While DR3/DR4 are the classic answers, **DQ2** (linked with DR3) and **DQ8** (linked with DR4) are the specific alleles that provide the highest risk for T1DM. * **Protective Allele:** **HLA-DRB1*0403** and **HLA-DQB1*0602** are known to provide *protection* against Type 1 DM. * **Other DR3/DR4 Associations:** HLA-DR3 is also associated with Celiac disease, SLE, and Graves' disease. HLA-DR4 is strongly associated with Rheumatoid Arthritis.
Question 508: A 49-year-old male schoolteacher presents with a neck swelling that has a palpable bounding pulse. Which test would be most likely to establish a possible cause of the underlying condition?
- A. Funduscopic eye examination
- B. Liver-spleen scan
- C. Thyroid function studies (Correct Answer)
- D. X-ray of the chest and cervical spine
Explanation: ### Explanation **Correct Answer: C. Thyroid function studies** The clinical finding of a **palpable bounding pulse** over a neck swelling (thyroid gland) is a classic sign of increased vascularity. This is most commonly associated with **Graves' disease** (hyperthyroidism). In Graves' disease, the thyroid gland becomes hypermetabolic and hypervascular; the increased blood flow can manifest as a palpable **thrill** or an audible **bruit** [1]. Therefore, the most logical step to establish the underlying cause (hyperthyroidism) is performing **Thyroid Function Studies** (TSH, Free T3, and Free T4) [1]. **Analysis of Incorrect Options:** * **A. Funduscopic eye examination:** While Graves' disease is associated with ophthalmopathy (exophthalmos), fundoscopy is primarily used to evaluate retinal changes (e.g., hypertension or diabetes) and would not diagnose the cause of a vascular neck swelling. * **B. Liver-spleen scan:** This is used to evaluate hepatosplenomegaly or functional reticuloendothelial issues and has no diagnostic value for thyroid pathology. * **D. X-ray of the chest and cervical spine:** While these might show tracheal deviation or retrosternal extension in a large goiter, they provide no information regarding the functional or vascular status of the gland. **NEET-PG High-Yield Pearls:** * **Vascular Goiter:** A bruit or thrill over the thyroid is almost pathognomonic for **Graves' disease**. It is rarely seen in other forms of goiter [1]. * **Pemberton’s Sign:** If a large goiter causes facial flushing and inspiratory stridor when the patient raises both arms, it indicates superior vena cava syndrome due to a retrosternal goiter. * **Diagnosis:** The initial screening test for thyroid dysfunction is **Serum TSH** [1]. In Graves', TSH is suppressed, while T3 and T4 are elevated. * **Triad of Graves':** Hyperthyroidism, Exophthalmos, and Pretibial Myxedema (Dermopathy).
Question 509: Which of the following is NOT a risk factor for type 2 diabetes mellitus that warrants early screening for diabetes?
- A. Family history
- B. Hypertension
- C. Polycystic ovary syndrome
- D. Alcoholism (Correct Answer)
Explanation: **Explanation:** The screening criteria for Type 2 Diabetes Mellitus (T2DM) in asymptomatic adults are primarily based on the **ADA (American Diabetes Association) guidelines**. Screening is indicated for all adults starting at age 35, or earlier in individuals who are overweight/obese (BMI ≥25 kg/m² or ≥23 kg/m² in Asians) and have one or more additional risk factors. **Why Alcoholism is the Correct Answer:** While chronic excessive alcohol consumption can lead to chronic pancreatitis (resulting in Type 3c diabetes), [1] **alcoholism itself is not a standardized risk factor** for the early screening of T2DM in asymptomatic individuals. In fact, moderate alcohol consumption has sometimes been paradoxically associated with improved insulin sensitivity, though it is never recommended as a preventive measure. **Analysis of Incorrect Options:** * **Family History:** A first-degree relative with diabetes significantly increases genetic predisposition, warranting early screening. * **Hypertension:** Blood pressure ≥140/90 mmHg or being on therapy for hypertension is a core component of metabolic syndrome and a major risk factor for insulin resistance. * **Polycystic Ovary Syndrome (PCOS):** PCOS is strongly associated with profound insulin resistance and acanthosis nigricans, placing these women at a high risk for early-onset T2DM. **High-Yield Clinical Pearls for NEET-PG:** * **Other Screening Criteria:** HDL cholesterol <35 mg/dL, Triglycerides >250 mg/dL, History of Gestational Diabetes (GDM), and Physical Inactivity. * **Asian-Specific Cut-off:** For the Indian population, a **BMI ≥23 kg/m²** is the threshold to trigger screening if other risk factors are present. * **Prediabetes:** Individuals with HbA1c ≥5.7%, [2] Impaired Glucose Tolerance (IGT), or Impaired Fasting Glucose (IFG) should be tested annually.
Question 510: Males who are sexually underdeveloped with rudimentary testes and prostate glands, sparse pubic and facial hair, long arms and legs, and large hands and feet are likely to have which chromosome complement?
- A. 45, XYY
- B. 46, XY
- C. 46, XXY (Correct Answer)
- D. 46, X
Explanation: ### Explanation The clinical presentation described is characteristic of **Klinefelter Syndrome**, the most common cause of congenital hypogonadism in males [1]. **1. Why the Correct Answer (46, XXY) is Right:** Klinefelter Syndrome typically results from **meiotic non-disjunction** of sex chromosomes, leading to a **47, XXY** karyotype (Note: The option 46, XXY in the question is a common shorthand representation in exams, though technically 47, XXY is the standard nomenclature). * **Hypogonadism:** The extra X chromosome causes dysgenesis of seminiferous tubules and Leydig cell dysfunction, leading to low testosterone and rudimentary testes/prostate [1], [2]. * **Eunuchoid Body Habitus:** Low testosterone levels before epiphyseal closure result in delayed fusion of growth plates. This leads to increased bone length, specifically **long extremities** (long arms/legs) and tall stature [1]. * **Secondary Sexual Characteristics:** Sparse facial/pubic hair and gynecomastia occur due to the decreased androgen-to-estrogen ratio. **2. Why the Other Options are Wrong:** * **45, XYY (Jacob’s Syndrome):** These individuals are usually phenotypically normal, very tall, and may have behavioral issues or cystic acne, but they have normal primary and secondary sexual development. * **46, XY:** This is the normal male karyotype. * **45, X (Turner Syndrome):** This affects females. It presents with short stature, webbed neck, and streak ovaries [3]. (Note: Option D "46, X" is a typo for 45, X). **3. NEET-PG High-Yield Pearls:** * **Biochemical Profile:** ↑ FSH, ↑ LH (Hypergonadotropic), ↓ Testosterone, and ↑ Estradiol [1]. * **Histology:** Characterized by **hyalinization and fibrosis of seminiferous tubules** and "clumping" of Leydig cells [1]. * **Infertility:** It is a leading cause of non-obstructive azoospermia [1]. * **Associated Risks:** Increased risk of **Breast Cancer** (20x higher than normal males), extragonadal germ cell tumors, and autoimmune diseases (SLE) [4]. * **Barr Body:** Positive (due to the extra X chromosome).
Practice by Chapter
Diabetes Mellitus
Practice Questions
Thyroid Disorders
Practice Questions
Adrenal Gland Disorders
Practice Questions
Pituitary Disorders
Practice Questions
Calcium and Bone Metabolism
Practice Questions
Reproductive Endocrinology
Practice Questions
Lipid Disorders
Practice Questions
Endocrine Hypertension
Practice Questions
Multiple Endocrine Neoplasia
Practice Questions
Obesity and Metabolic Syndrome
Practice Questions
Neuroendocrine Tumors
Practice Questions
Endocrine Emergencies
Practice Questions
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