Endocrinology Practice Questions

Q: Which of the following features is NOT typically seen in Cushing's Syndrome?

Hypoglycemia. Cushing’s Syndrome is characterized by chronic exposure to excess glucocorticoids (cortisol). Cortisol is a "stress hormone" that acts as a potent **insulin antagonist**. **1. Why Hypoglycemia is the Correct Answer:** Glucocorticoids stimulate gluconeogenesis in the liver and decrease peripheral glucose uptake in muscles and adipose tissue. Therefore, excess cortisol leads to **Hyperglycemia** (impaired glucose tolerance or "Steroid Diabetes"), not hypoglycemia. Hypoglycemia is instead a hallmark of Adrenal Insufficiency (Addison’s Disease). **2. Analysis of Incorrect Options:** * **Hypertension (B):** This is a classic feature. Cortisol causes hypertension by increasing peripheral vascular resistance, enhancing sensitivity to catecholamines, and exerting mineralocorticoid effects (sodium and water retention) at high levels. * **Frank Psychosis (C):** Glucocorticoids significantly impact the central nervous system. Neuropsychiatric manifestations range from emotional lability and depression to overt "steroid psychosis" and cognitive deficits. * **Hypokalemia (D):** At high concentrations (especially in Ectopic ACTH syndrome), cortisol overwhelms the 11β-HSD2 enzyme in the kidneys and binds to mineralocorticoid receptors, leading to potassium excretion and metabolic alkalosis. **Clinical Pearls for NEET-PG:** * **Screening Test of Choice:** 24-hour urinary free cortisol or Low-dose Dexamethasone Suppression Test (LDDST) [2]. * **Most Common Cause:** Iatrogenic (exogenous steroids). * **Most Common Endogenous Cause:** Cushing’s Disease (Pituitary adenoma) [1]. * **High-Yield Sign:** Proximal muscle wasting (due to protein catabolism) with centripetal obesity and violaceous striae (>1cm wide) [1].

Q: Hirsutism is seen in all of the following conditions except?

Hyperthyroidism. **Explanation:** Hirsutism is defined as the presence of terminal hair in females in a male-pattern distribution (e.g., face, chest, back). It is primarily driven by an excess of circulating androgens or increased sensitivity of hair follicles to androgens. **Why Hyperthyroidism is the Correct Answer:** Hyperthyroidism is **not** associated with hirsutism. In fact, hyperthyroidism is typically associated with **thinning of hair** or diffuse alopecia. While thyroid disorders can affect Sex Hormone Binding Globulin (SHBG) levels, they do not cause the androgen excess required to produce terminal hair growth in a male distribution. **Analysis of Incorrect Options:** * **Acromegaly:** Excess Growth Hormone (GH) stimulates the production of IGF-1, which can lead to skin thickening and hirsutism. Additionally, GH can have a direct effect on the hair follicle and is often associated with insulin resistance, which lowers SHBG and increases free androgens. * **Arrhenoblastoma (Sertoli-Leydig Cell Tumor):** This is a rare ovarian tumor that secretes high levels of testosterone. It is a classic cause of rapid-onset, severe hirsutism often accompanied by virilization. * **PCOD (Polycystic Ovarian Disease):** This is the **most common cause** of hirsutism. It involves a state of hyperandrogenism driven by high LH levels and insulin resistance. **High-Yield Clinical Pearls for NEET-PG:** * **Ferriman-Gallwey Score:** Used to clinically grade hirsutism (Score ≥ 8 is significant). * **SHBG Connection:** Any condition that lowers SHBG (like Obesity, Hypothyroidism, or Acromegaly) increases the "Free Androgen Index," leading to hirsutism. * **Rapid Onset Hirsutism:** Always suspect an androgen-secreting tumor (Adrenal or Ovarian) if hirsutism develops rapidly or is accompanied by virilization (clitoromegaly, deepening of voice). * **Drug-induced Hirsutism:** Common culprits include Minoxidil, Phenytoin, Cyclosporine, and Anabolic steroids.

Q: What is the most common neuropathy in Diabetes Mellitus?

Distal symmetric neuropathy. **Explanation:** **Distal Symmetric Polyneuropathy (DSPN)** is the most common form of diabetic neuropathy, affecting approximately 50% of all patients with diabetes during their lifetime. It typically presents in a "stocking-and-glove" distribution because the longest nerve fibers are the most vulnerable to metabolic and microvascular injury [1]. The underlying pathophysiology involves chronic hyperglycemia leading to polyol pathway activation, oxidative stress, and advanced glycation end-products (AGEs), which cause progressive axonal degeneration [1]. **Analysis of Incorrect Options:** * **Autonomic Neuropathy:** While common and clinically significant (causing resting tachycardia, gastroparesis, or orthostatic hypotension), it usually occurs alongside or after the development of DSPN [1]. * **Mononeuropathy:** This involves isolated damage to a single nerve (e.g., Cranial Nerve III or Median nerve). While diabetes is a leading cause of mononeuropathies, they are far less frequent than the symmetric variety. * **Amyotrophy (Diabetic Lumbosacral Radiculoplexus Neuropathy):** This is a rare manifestation characterized by severe pain followed by muscle weakness and atrophy, usually in the proximal thigh muscles. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest Sign:** Loss of vibration sense (tested with a 128 Hz tuning fork) and loss of ankle reflex are often the earliest clinical findings [1]. * **Screening:** The **10g Semmes-Weinstein monofilament test** is the gold standard for identifying a "foot at risk" for ulceration [1]. * **Cranial Nerve Involvement:** CN III is the most common cranial nerve affected; it typically presents with **pupillary sparing** (due to the peripheral location of parasympathetic fibers). * **First-line Treatment:** Pregabalin, Duloxetine, or Gabapentin are preferred for symptomatic pain management.

Q: Which of the following is NOT a feature of hypocalcemia?

Depressed tendon reflexes. The correct answer is **C. Depressed tendon reflexes**. **1. Underlying Medical Concept:** Hypocalcemia increases neuromuscular excitability. Calcium ions normally stabilize the neuronal membrane by blocking sodium channels. When extracellular calcium levels are low, the threshold for depolarization decreases, making neurons **hyperexcitable**. This leads to spontaneous firing of motor and sensory nerves. Consequently, hypocalcemia is characterized by **hyperreflexia** (brisk tendon reflexes), tetany, and muscle spasms. Depressed or absent reflexes are typically seen in **hypercalcemia** or hypermagnesemia, where the membrane is over-stabilized. **2. Analysis of Incorrect Options:** * **A & B (Numbness, tingling, and circumoral paresthesia):** These are the earliest sensory manifestations of hypocalcemia. The hyperexcitability of sensory nerve fibers manifests as "pins and needles" sensations, particularly around the mouth (circumoral) and in the fingertips. * **D (Skin irritability and sensitivity):** Chronic hypocalcemia affects ectodermal tissues, leading to dry, scaly skin, brittle nails, and dermatological sensitivity. Neuromuscular irritability also manifests as "irritability" in the clinical sense (agitation or seizures). **3. High-Yield Clinical Pearls for NEET-PG:** * **Chvostek’s Sign:** Tapping the facial nerve leads to twitching of facial muscles. * **Trousseau’s Sign:** Carpopedal spasm induced by inflating a BP cuff above systolic pressure for 3 minutes (more specific than Chvostek’s). * **ECG Finding:** The classic hallmark is **prolonged QT interval** (due to lengthening of the ST segment) [1]. * **Etiology:** Most common cause is post-thyroidectomy (accidental parathyroid removal) [1] or Vitamin D deficiency [1].

Q: What is the effect of calcitonin on bone resorption?

Inhibits resorption. Calcitonin is a 32-amino acid peptide hormone secreted by the **parafollicular cells (C-cells) of the thyroid gland**. Its primary physiological role is to lower plasma calcium levels, acting as a functional antagonist to Parathyroid Hormone (PTH). [1] **Why Option A is correct:** Calcitonin directly **inhibits bone resorption** by acting on specific receptors located on **osteoclasts**. [1] Upon binding, it causes the osteoclasts to lose their "ruffled borders" and shrink, effectively decreasing their resorptive activity. This leads to a reduction in the release of calcium and phosphate from the bone matrix into the blood. [1] **Why the other options are incorrect:** * **Option B:** Promoting resorption is the primary function of **PTH** and **Vitamin D** (in high doses), which increase blood calcium. * **Option C:** Calcitonin has a unidirectional effect on bone; it is purely anti-resorptive and does not stimulate resorption under any physiological condition. * **Option D:** While calcitonin prevents the breakdown of bone, it does not directly "enhance" the complex process of mineralization (which requires adequate calcium, phosphate, and alkaline phosphatase activity). Its effect is passive preservation rather than active formation. **High-Yield Clinical Pearls for NEET-PG:** * **Marker:** Serum calcitonin is a sensitive tumor marker for **Medullary Thyroid Carcinoma (MTC)**. * **Therapeutic Use:** Exogenous calcitonin (often Salmon calcitonin due to higher potency) is used in the acute management of **Hypercalcemic crisis**, **Paget’s disease of bone**, and to provide analgesic effects in **osteoporotic vertebral fractures**. * **Escape Phenomenon:** The hypocalcemic effect of calcitonin is short-lived because osteoclasts eventually "downregulate" their receptors, a process known as tachyphylaxis or the "escape phenomenon." [1]

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

Increased renin level. ### Explanation **Primary Hyperaldosteronism (Conn’s Syndrome)** is characterized by the autonomous overproduction of aldosterone from the adrenal cortex (most commonly due to an adrenal adenoma or bilateral adrenal hyperplasia). **Why "Increased renin level" is the correct answer:** In primary hyperaldosteronism, the excess aldosterone leads to sodium and water retention, which increases effective circulating volume and blood pressure. This physiological state triggers a **negative feedback mechanism** on the juxtaglomerular apparatus, resulting in the **suppression of renin**. Therefore, a **low plasma renin level** is a hallmark of the disease. An increased renin level would instead point toward *secondary* hyperaldosteronism (e.g., renal artery stenosis). **Analysis of Incorrect Options:** * **A. Hypokalemia:** Aldosterone acts on the principal cells of the collecting duct to secrete potassium into the urine. Chronic excess leads to significant depletion of serum potassium. * **B. Hypertension:** Increased sodium reabsorption in the distal nephron leads to volume expansion, making hypertension a cardinal clinical feature. * **C. Hypernatremia:** While sodium is retained, it is often "mild" due to the **Aldosterone Escape Phenomenon** (where ANP release prevents massive edema); however, serum sodium levels typically remain at the high end of normal or slightly elevated. **NEET-PG High-Yield Pearls:** * **Screening Test of Choice:** Plasma Aldosterone Concentration (PAC) to Plasma Renin Activity (PRA) ratio. A **PAC:PRA ratio > 20-30** is highly suggestive. * **Confirmatory Test:** Saline infusion test (failure to suppress aldosterone) or Oral Salt Loading test. * **Metabolic State:** Patients typically exhibit **Metabolic Alkalosis** (due to H+ secretion in the intercalated cells). * **Clinical Clue:** Suspect this in a young patient with resistant hypertension and unexplained hypokalemia.

Q: A 35-year-old male stockbroker presents with excessive nervousness, irritability, and a subjective complaint of the office being too hot. Physical examination reveals a goiter and exophthalmia. Laboratory analysis of his blood reveals high antibody titers against the thyroid-stimulating hormone (TSH) receptor. Which of the following is the most likely diagnosis?

Graves' disease. **Explanation:** The clinical presentation of nervousness, heat intolerance, goiter, and exophthalmia (proptosis) is classic for **Graves' disease**, the most common cause of hyperthyroidism. **1. Why Graves' Disease is Correct:** Graves' disease is a **Type II Hypersensitivity** reaction. It is characterized by the production of **Thyroid Stimulating Immunoglobulins (TSI)**. These autoantibodies bind to and activate the **TSH receptors** on thyroid follicular cells, mimicking the action of TSH. This leads to autonomous overproduction of thyroid hormones (T3 and T4) and hypertrophy of the gland (goiter). The exophthalmia is due to antibody-mediated inflammation and glycosaminoglycan deposition in the retro-orbital tissues. **2. Why Other Options are Incorrect:** * **Goodpasture Syndrome:** Also a Type II hypersensitivity, but involves antibodies against the **alpha-3 chain of Type IV collagen** in glomerular and alveolar basement membranes, leading to hemoptysis and hematuria. * **Hashimoto Disease:** The most common cause of hypothyroidism. It involves **Type IV (cell-mediated)** and Type II hypersensitivity, with antibodies against **Thyroid Peroxidase (TPO)** and Thyroglobulin, leading to follicular destruction rather than stimulation. * **Juvenile-onset Diabetes (Type 1 DM):** Primarily a **Type IV hypersensitivity** where T-cells destroy insulin-producing beta cells in the pancreatic islets. **NEET-PG High-Yield Pearls:** * **Mechanism:** Graves' is a unique Type II hypersensitivity because the antibody is **stimulatory** rather than cytotoxic. * **HLA Association:** Strongly associated with **HLA-DR3** and HLA-B8. * **Triad:** Hyperthyroidism, Exophthalmos, and Pretibial Myxedema. * **Lab Profile:** Low TSH, High Free T4/T3, and positive Anti-TSH receptor antibodies.

Question 1

Which of the following features is NOT typically seen in Cushing's Syndrome?

Accepted Answer

Hypoglycemia

Answer

Hypertension

Answer

Frank psychosis

Answer

Hypokalemia

Question 2

Hirsutism is seen in all of the following conditions except?

Accepted Answer

Hyperthyroidism

Answer

Acromegaly

Answer

Arrhenoblastoma

Answer

PCOD

Question 3

A 25-year-old female, several months postpartum and breast-feeding, presents with acute cessation of lactation. She has not menstruated since delivery and reports fatigue and cold intolerance. Laboratory workup reveals deficiency of ACTH and other anterior pituitary hormones. What is the most likely cause of this patient's signs and symptoms?

Accepted Answer

Sheehan's syndrome

Answer

Craniopharyngioma

Answer

Cushing's disease

Answer

Empty sella syndrome

Question 4

What is the most common neuropathy in Diabetes Mellitus?

Accepted Answer

Distal symmetric neuropathy

Answer

Autonomic neuropathy

Answer

Mononeuropathy

Answer

Amyotrophy

Question 5

A 16-year-old girl presents with a one-month history of visual disturbances, including difficulty seeing people unless they are directly in front of her and walking into doors. Her menstrual cycles have become irregular and have ceased in the past few months. Physical examination reveals bilateral temporal visual field deficits with normal nasal visual fields. A mass is identified inferior to the hypothalamus on cranial imaging. Which hormone do the cells within this mass most likely produce?

Accepted Answer

Thyroid-stimulating hormone

Answer

Oxytocin

Answer

Somatostatin

Answer

Thyrotropin-releasing hormone

Question 6

Which of the following is NOT a feature of hypocalcemia?

Accepted Answer

Depressed tendon reflexes

Answer

Numbness and tingling

Answer

Circumoral paresthesia

Answer

Skin irritability and sensitivity

Question 7

A 50-year-old man consults you because he has been having transient periods of rapid heart beat accompanied by sweating, flushing, and a sense of impending doom. Examination is unrevealing, with no evidence of arrhythmia at the time of the exam. However, the man's wife is a nurse, so the physician asks that she take vital signs the next time one of the episodes occurs. She does, and demonstrates a BP of 195/140 with heart rate 160/min during the episode. She promptly brings him to you, but the spell is over by the time that he is seen. Urinary measurement of which of the following would most likely be diagnostic in this case?

Accepted Answer

Vanillylmandelic acid (VMA)

Answer

Dehydroepiandrosterone (DHEA)

Answer

Human chorionic gonadotropin (hCG)

Answer

17-ketosteroids

Question 8

What is the effect of calcitonin on bone resorption?

Accepted Answer

Inhibits resorption

Answer

Promotes resorption

Answer

Has both properties

Answer

Enhances mineralization

Question 9

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

Accepted Answer

Increased renin level

Answer

Hypokalemia

Answer

Hypertension

Answer

Hypernatremia

Question 10

A 35-year-old male stockbroker presents with excessive nervousness, irritability, and a subjective complaint of the office being too hot. Physical examination reveals a goiter and exophthalmia. Laboratory analysis of his blood reveals high antibody titers against the thyroid-stimulating hormone (TSH) receptor. Which of the following is the most likely diagnosis?

Accepted Answer

Graves' disease

Answer

Goodpasture syndrome

Answer

Hashimoto disease

Answer

Juvenile-onset diabetes mellitus

Endocrinology — MCQs

Endocrinology — MCQs

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