Endocrinology Practice Questions

Q: A 45-year-old female presents with symptoms of thyrotoxicosis. The RAIU scan shows increased uptake. Which of the following is the most likely diagnosis?

Choriocarcinoma. The clinical presentation of thyrotoxicosis with **increased Radioactive Iodine Uptake (RAIU)** indicates that the thyroid gland is actively synthesizing new thyroid hormone (hyperthyroidism). [1] **Why Choriocarcinoma is correct:** Choriocarcinoma is a germ cell tumor that secretes extremely high levels of **human chorionic gonadotropin (hCG)**. The alpha-subunit of hCG is identical to that of **TSH**. At very high concentrations, hCG cross-reacts with TSH receptors in the thyroid gland, stimulating thyroid hormone production and increasing iodine trapping. This results in a high RAIU scan, similar to Graves' disease but without the ophthalmopathy. [2] **Why the other options are incorrect:** * **Hashimoto’s Thyroiditis:** Typically presents with hypothyroidism. During the initial "Hashitoxicosis" phase, thyrotoxicosis occurs due to the release of pre-formed hormones from gland destruction, resulting in **low/decreased RAIU**. [1] * **Struma Ovarii:** This is ectopic thyroid tissue within an ovarian teratoma. While it causes thyrotoxicosis, the iodine uptake occurs in the pelvis. The **neck RAIU scan will be low** because the endogenous TSH is suppressed. * **Thyrotoxicosis Factitia:** Caused by the exogenous ingestion of thyroid hormones. Since the thyroid gland is suppressed by the external hormone, the **RAIU scan will be low/absent**. [1] **High-Yield Clinical Pearls for NEET-PG:** * **High RAIU (>30%):** Graves’ Disease, Toxic Multinodular Goiter, Toxic Adenoma, TSH-secreting pituitary adenoma, and hCG-mediated thyrotoxicosis (Choriocarcinoma/Hydatidiform mole). [3] * **Low RAIU (<5%):** Thyroiditis (Subacute, Silent, Hashimoto's), Iodine overload (Jod-Basedow), Factitious thyrotoxicosis, and Ectopic thyroid (Struma ovarii). [1] * **Key Concept:** If thyrotoxicosis is present but the neck scan is "cold," always consider thyroiditis or an extrathyroidal source.

Q: Which of the following is NOT a feature of primary hyperaldosteronism?

Hyperkalemia. Primary Hyperaldosteronism (Conn’s Syndrome) is characterized by the autonomous overproduction of aldosterone, typically due to an adrenal adenoma or bilateral adrenal hyperplasia. **Why Hyperkalemia is the Correct Answer:** Aldosterone acts on the principal cells of the renal collecting ducts to increase the reabsorption of sodium and the **secretion of potassium and hydrogen ions** into the urine [1]. Consequently, excessive aldosterone leads to **hypokalemia**, not hyperkalemia [3]. Therefore, hyperkalemia is the "odd one out" and the correct answer. **Analysis of Other Options:** * **Hypertension:** Increased sodium reabsorption leads to water retention and expansion of extracellular fluid volume, resulting in hypertension [2]. Notably, this is often resistant to standard therapy. * **Hypokalemia:** As explained, increased renal potassium excretion leads to low serum potassium levels [3]. This can manifest as muscle weakness or cardiac arrhythmias. * **Polyuria:** Chronic hypokalemia can cause "hypokalemic nephropathy," which impairs the kidney's ability to concentrate urine (nephrogenic diabetes insipidus), leading to polyuria and polydipsia. **High-Yield Clinical Pearls for NEET-PG:** * **Screening Test:** Plasma Aldosterone Concentration (PAC) to Plasma Renin Activity (PRA) ratio. A ratio **>20-30** is highly suggestive. * **Confirmatory Test:** Oral or Intravenous Salt Loading Test (failure to suppress aldosterone). * **Metabolic State:** Patients typically exhibit **Metabolic Alkalosis** (due to $H^+$ loss) [1], [3]. * **Aldosterone Escape:** Edema is usually absent in primary hyperaldosteronism because of "atrial natriuretic peptide (ANP) mediated diuresis," which prevents massive fluid overload [2].

Q: Which of the following statements regarding the treatment of hypothyroidism in a patient with ischemic heart disease is true?

Low dose of Levothyroxine. ### Explanation **Core Concept:** In patients with hypothyroidism and concurrent **Ischemic Heart Disease (IHD)**, thyroid hormone replacement must be initiated with extreme caution. Levothyroxine increases the metabolic rate, oxygen consumption, and myocardial contractility [1]. In a heart with compromised coronary circulation, a sudden increase in cardiac demand can precipitate **angina, myocardial infarction, or fatal arrhythmias.** [1] **Why Option A is Correct:** The standard protocol for elderly patients or those with IHD is to **"Start Low and Go Slow."** The typical starting dose is **12.5 to 25 µg/day**, which is significantly lower than the standard replacement dose [2]. The dose is then titrated upwards in small increments every 4–6 weeks based on clinical response and TSH levels to allow the myocardium to adapt to the increased metabolic demand [2]. **Why Other Options are Incorrect:** * **Option B (Normal dose):** A full replacement dose (approx. 1.6 µg/kg) can cause a rapid increase in heart rate and stroke volume, potentially leading to an acute coronary syndrome or heart failure [2]. * **Option C (Do not use):** Untreated hypothyroidism itself worsens cardiovascular risk factors (dyslipidemia, hypertension) and can lead to myxedema coma. Treatment is necessary but must be cautious. * **Option D (Thyroid extract):** Desiccated thyroid extracts contain T3, which has a rapid onset and can cause "peaks" in hormone levels, making it much more dangerous for the heart than the stable T4 (Levothyroxine). **High-Yield Clinical Pearls for NEET-PG:** * **Standard Starting Dose (Healthy Adult):** 1.6 µg/kg/day. * **Starting Dose (IHD/Elderly):** 12.5–25 µg/day [2]. * **Monitoring:** TSH is the gold standard; check 6–8 weeks after any dose adjustment [2]. * **Drug Interaction:** Levothyroxine increases the effect of Warfarin (monitor PT/INR) and may require an increase in Insulin/Oral Hypoglycemic doses.

Q: What is the most common organ involved in Multiple Endocrine Neoplasia type I?

Parathyroid. **Explanation:** **Multiple Endocrine Neoplasia type 1 (MEN1)**, 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 Parathyroid is correct:** Primary Hyperparathyroidism (PHPT) is the **most common** and often the **earliest** clinical manifestation of MEN1, occurring in over **95% of patients** by age 40. Unlike sporadic cases which usually involve a single adenoma, MEN1-associated hyperparathyroidism typically involves **multiglandular hyperplasia**. **Why other options are incorrect:** * **B. Thyroid:** While thyroid adenomas or goiters can occasionally be seen in MEN1 patients, they are not a defining feature of the syndrome. Medullary thyroid carcinoma is a hallmark of MEN 2A and 2B, not MEN 1. * **C. Adrenal:** Adrenal cortical lesions (like bilateral hyperplasia or adenomas) occur in about 20-40% of MEN1 cases but are significantly less common than parathyroid involvement and are often non-functional. * **D. Testis:** Testicular tumors are not a standard component of the MEN1 clinical triad. **High-Yield Clinical Pearls for NEET-PG:** * **The 3 Ps of MEN1:** Parathyroid (95%), Pancreatic Islet cells (e.g., Gastrinoma/Zollinger-Ellison Syndrome - 40-70%), and Anterior Pituitary (e.g., Prolactinoma - 30-40%). * **Most common Pancreatic tumor in MEN1:** Gastrinoma (though Insulinomas are also frequent). * **Screening:** If a patient presents with multiglandular parathyroid disease at a young age, always screen for MEN1. * **Cutaneous markers:** Look for facial angiofibromas, collagenomas, and lipomas, which are common non-endocrine findings in MEN1.

Q: An adult patient weighing 70 kg has a fasting blood sugar of 180 mg/dl. What is the most likely condition?

Hyperglycemia. The patient presents with a fasting blood sugar (FBS) of **180 mg/dl**, which is significantly higher than the normal physiological range. According to the American Diabetes Association (ADA) criteria, a fasting plasma glucose level of **≥126 mg/dl** is diagnostic of Diabetes Mellitus [1]. Therefore, the most accurate description of this biochemical state is **Hyperglycemia** [2]. **Analysis of Options:** * **Hyperglycemia (Correct):** Defined as an elevation in blood glucose levels [2]. In a 70 kg adult, the normal fasting range is typically 70–100 mg/dl. A value of 180 mg/dl confirms hyperglycemia. * **Ketoacidosis (Incorrect):** While Diabetic Ketoacidosis (DKA) involves hyperglycemia, it is a complex metabolic triad consisting of hyperglycemia, ketonemia, and metabolic acidosis (pH <7.3). We cannot diagnose DKA based on a glucose reading alone without clinical signs (Kussmaul breathing, fruity breath) and lab evidence of ketones/acidosis [3]. * **Hypoglycemia (Incorrect):** This refers to abnormally low blood glucose, typically defined as <70 mg/dl in diabetic patients or <55 mg/dl in non-diabetic individuals. * **Thyroidism (Incorrect):** This is a vague term. While hyperthyroidism can cause secondary hyperglycemia (due to increased glycogenolysis), it is a thyroid disorder, not a description of a blood glucose level. **NEET-PG High-Yield Pearls:** 1. **Diagnostic Criteria for Diabetes:** * FBS ≥ 126 mg/dl [1] * 2-hour Post-Prandial (OGTT) ≥ 200 mg/dl * HbA1c ≥ 6.5% * Random Blood Sugar ≥ 200 mg/dl with symptoms of polyuria/polydipsia. 2. **Prediabetes:** FBS between 100–125 mg/dl (Impaired Fasting Glucose) [1]. 3. **Renal Threshold for Glucose:** Glucose starts appearing in urine (glycosuria) when blood levels exceed **180 mg/dl** [3].

Q: Peripheral nerve involvement, presenting as pain, paresthesia, motor weakness, and reflex loss, develops in a significant percentage of patients with which of the following conditions?

Diabetes mellitus. **Explanation:** **Diabetes Mellitus (DM)** is the most common cause of peripheral neuropathy worldwide. The pathogenesis involves chronic hyperglycemia leading to the accumulation of sorbitol (via the polyol pathway), advanced glycation end-products (AGEs), and increased oxidative stress. These factors cause microvascular damage to the *vasa nervorum*, leading to nerve ischemia. The classic presentation is a **Symmetric Distal Sensorimotor Polyneuropathy** ("stocking-and-glove" distribution), characterized by pain, paresthesia, loss of vibration/proprioception, and diminished deep tendon reflexes (especially the ankle jerk). **Why other options are incorrect:** * **Hypoparathyroidism:** Primarily presents with features of hypocalcemia, such as tetany, carpopedal spasm, and seizures. While it causes neuromuscular irritability (Chvostek/Trousseau signs), it does not typically cause structural peripheral nerve degeneration or motor weakness. * **Adrenal Insufficiency:** Presents with hypotension, hyperpigmentation, and electrolyte imbalances (hyponatremia, hyperkalemia). It does not involve peripheral nerve pathology. * **Hyperthyroidism:** More commonly associated with **proximal myopathy** (weakness of hip/shoulder girdles) rather than peripheral neuropathy. Reflexes in hyperthyroidism are characteristically "brisk" or hyperreflexic, not lost. **High-Yield Clinical Pearls for NEET-PG:** * **Mononeuritis Multiplex:** DM is a leading cause; it involves the involvement of two or more non-contiguous nerve trunks. * **Diabetic Amyotrophy:** A plexopathy presenting as severe pain followed by weakness and wasting of the proximal thigh muscles. * **Cranial Nerve Involvement:** The **3rd Cranial Nerve** is most commonly affected in DM, typically presenting with **pupillary sparing** (due to ischemic rather than compressive injury).

Q: A 46-year-old woman with hypertension and diabetes mellitus type II presents with elevated blood pressure despite diet and exercise. She is taking metformin for her diabetes. Her vital signs are: temperature 37°C (98.6°F), blood pressure 146/72 mmHg, pulse 76/min, respirations 16/min, and oxygen saturation 98% on room air. Which of the following medications is most likely to be prescribed?

Lisinopril. **Explanation:** The correct answer is **Lisinopril (Option C)**. **Why Lisinopril is the drug of choice:** In patients with **Diabetes Mellitus and Hypertension**, ACE inhibitors (like Lisinopril) or ARBs are the first-line antihypertensive agents. The underlying medical concept is **renoprotection**. ACE inhibitors reduce intraglomerular pressure by dilating the efferent arteriole, thereby slowing the progression of diabetic nephropathy and reducing albuminuria. Even in the absence of overt proteinuria, they are preferred in diabetics to prevent chronic kidney disease (CKD). **Why the other options are incorrect:** * **Amlodipine (Option A):** While Calcium Channel Blockers (CCBs) are effective antihypertensives, they do not offer the same level of renal protection as ACE inhibitors in diabetic patients. They are typically used as second-line or add-on therapy. * **Furosemide (Option B):** Loop diuretics are primarily used for fluid overload states (e.g., heart failure, edema) rather than primary hypertension management, unless the patient has advanced CKD (GFR <30). * **Spironolactone (Option D):** This potassium-sparing diuretic is generally reserved for resistant hypertension or primary aldosteronism. It is not a first-line agent for uncomplicated diabetic hypertension. **Clinical Pearls for NEET-PG:** * **Target BP in Diabetes:** According to most guidelines (ADA/JNC), the target is generally **<130/80 mmHg**. * **Monitoring:** Always check serum **creatinine and potassium** levels within 1-2 weeks of starting an ACE inhibitor. A rise in creatinine up to 30% is acceptable. * **Contraindication:** ACE inhibitors are strictly **contraindicated in pregnancy** (teratogenic) and in patients with bilateral renal artery stenosis. * **Side Effect:** The most common side effect of ACE inhibitors is a **dry cough** (due to bradykinin accumulation); if this occurs, switch the patient to an ARB (e.g., Losartan).

Q: Which of the following is a microvascular complication of diabetes mellitus?

Retinopathy. Chronic hyperglycemia in diabetes mellitus leads to vascular damage categorized into two main types: **Microvascular** (affecting small capillaries) and **Macrovascular** (affecting large arteries) [1]. **Why Retinopathy is Correct:** Diabetic retinopathy is the classic hallmark of **microvascular** disease. It occurs due to basement membrane thickening, loss of pericytes, and increased capillary permeability in the retinal vessels [1]. This leads to microaneurysms, hemorrhages, and neovascularization [3]. Other primary microvascular complications include **Nephropathy** and **Neuropathy**. **Analysis of Incorrect Options:** * **Coronary circulation (B):** This is a **macrovascular** complication. Macrovascular disease involves atherosclerosis of large vessels, leading to Coronary Artery Disease (CAD), Stroke (Cerebrovascular disease), and Peripheral Arterial Disease (PAD) [1]. * **Peripheral (A) and Autonomic (D) Neuropathy:** While these are microvascular in origin (due to ischemia of the *vasa nervorum*), in the context of standard medical examinations and the "classic triad" of diabetic complications, **Retinopathy, Nephropathy, and Neuropathy** are all microvascular [1], [4]. However, if a single best answer must be chosen among these, Retinopathy is the most direct clinical manifestation of small-vessel damage. *Note: In many MCQ formats, if multiple microvascular options are present, the question may be flawed or looking for the "most" characteristic one.* **High-Yield Clinical Pearls for NEET-PG:** * **Earliest sign of Nephropathy:** Microalbuminuria (30–300 mg/day). * **Earliest sign of Retinopathy:** Microaneurysms [3]. * **Kimmelstiel-Wilson (KW) lesions:** Pathognomonic for diabetic nephropathy (nodular glomerulosclerosis). * **Metabolic Memory:** Early glycemic control prevents long-term microvascular complications even if control worsens later [2].

Q: Metabolic syndrome consists of all of the following, EXCEPT:

High LDL cholesterol. **Explanation:** Metabolic syndrome (also known as Syndrome X or Insulin Resistance Syndrome) is a cluster of metabolic abnormalities that significantly increase the risk of cardiovascular disease and Type 2 Diabetes Mellitus [1]. The diagnosis is most commonly based on the **NCEP ATP III criteria**. **Why High LDL is the correct answer:** While elevated LDL (Low-Density Lipoprotein) is a major risk factor for atherosclerosis [1], it is **not** a diagnostic component of Metabolic Syndrome. The lipid abnormalities specific to this syndrome are **Hypertriglyceridemia** and **Low HDL cholesterol** [1]. This distinction is a frequent "trap" in postgraduate exams. **Analysis of other options:** * **High blood pressure (Option A):** A core component. Defined as BP ≥130/85 mmHg or being on antihypertensive medication. * **Low HDL cholesterol (Option C):** A core component. Defined as 102 cm (40 in) in men or >88 cm (35 in) in women (Note: Cut-offs are lower for South Asians: >90 cm for men, >80 cm for women). **High-Yield Clinical Pearls for NEET-PG:** 1. **NCEP ATP III Criteria:** Diagnosis requires **3 out of 5** of the following: * Abdominal obesity * Triglycerides ≥150 mg/dL * HDL <40 (M) / <50 (F) mg/dL * BP ≥130/85 mmHg * Fasting Glucose ≥100 mg/dL 2. **Pathophysiology:** The primary underlying mechanism is **Insulin Resistance**. 3. **Acanthosis Nigricans:** Often seen clinically as a cutaneous marker of the underlying insulin resistance.

Question 1

A 45-year-old female presents with symptoms of thyrotoxicosis. The RAIU scan shows increased uptake. Which of the following is the most likely diagnosis?

Accepted Answer

Choriocarcinoma

Answer

Hashimoto's thyroiditis

Answer

Struma ovarii

Answer

Thyrotoxicosis factitia

Question 2

Which of the following is NOT a feature of primary hyperaldosteronism?

Accepted Answer

Hyperkalemia

Answer

Polyuria

Answer

Hypertension

Answer

Hypokalemia

Question 3

Which of the following statements regarding the treatment of hypothyroidism in a patient with ischemic heart disease is true?

Accepted Answer

Low dose of Levothyroxine

Answer

Normal dose of Levothyroxine

Answer

Do not use Levothyroxine

Answer

Use thyroid extract

Question 4

What is the most common organ involved in Multiple Endocrine Neoplasia type I?

Accepted Answer

Parathyroid

Answer

Thyroid

Answer

Adrenal

Answer

Testis

Question 5

An adult patient weighing 70 kg has a fasting blood sugar of 180 mg/dl. What is the most likely condition?

Accepted Answer

Hyperglycemia

Answer

Ketoacidosis

Answer

Hypoglycemia

Answer

Thyroidism

Question 6

Peripheral nerve involvement, presenting as pain, paresthesia, motor weakness, and reflex loss, develops in a significant percentage of patients with which of the following conditions?

Accepted Answer

Diabetes mellitus

Answer

Hypoparathyroidism

Answer

Adrenal insufficiency

Answer

Hyperthyroidism

Question 7

In Conn's syndrome, which of the following is true?

Accepted Answer

Patients most often have elevated blood pressure.

Answer

The usual treatment involves managing blood pressure and most symptoms.

Answer

Muscle twitching is not typically associated with this condition.

Answer

All of the above are true.

Question 8

A 46-year-old woman with hypertension and diabetes mellitus type II presents with elevated blood pressure despite diet and exercise. She is taking metformin for her diabetes. Her vital signs are: temperature 37°C (98.6°F), blood pressure 146/72 mmHg, pulse 76/min, respirations 16/min, and oxygen saturation 98% on room air. Which of the following medications is most likely to be prescribed?

Accepted Answer

Lisinopril

Answer

Amlodipine

Answer

Furosemide

Answer

Spironolactone

Question 9

Which of the following is a microvascular complication of diabetes mellitus?

Accepted Answer

Retinopathy

Answer

Peripheral neuropathy

Answer

Coronary circulation

Answer

Autonomic neuropathy

Question 10

Metabolic syndrome consists of all of the following, EXCEPT:

Accepted Answer

High LDL cholesterol

Answer

High blood pressure

Answer

Low HDL cholesterol

Answer

Increased abdominal circumference

Endocrinology — MCQs

Endocrinology — MCQs

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