Endocrinology Practice Questions

Q: A 35-year-old woman presents with amenorrhea and weight loss despite increased appetite. The history and physical examination reveal exophthalmos, fine resting tremor, tachycardia, and warm, moist skin. What laboratory test for thyroid function would be expected to yield a decreased value?

Thyroid stimulating hormone. The clinical presentation of weight loss with increased appetite, amenorrhea, exophthalmos, tachycardia, and fine tremors is a classic description of **Hyperthyroidism**, most likely **Graves' Disease** (suggested by exophthalmos) [2]. **Why TSH is the correct answer:** In primary hyperthyroidism, the thyroid gland overproduces thyroid hormones (T3 and T4). According to the **negative feedback mechanism**, high levels of circulating Free T4 and T3 inhibit the anterior pituitary gland from secreting **Thyroid Stimulating Hormone (TSH)** [3]. Consequently, a suppressed (decreased) TSH level is the most sensitive initial marker for diagnosing primary hyperthyroidism [2]. **Analysis of Incorrect Options:** * **Free T4 (A):** In hyperthyroidism, the thyroid gland is overactive, leading to **increased** levels of Free T4 [3]. * **Radioactive Iodine Uptake (B):** In Graves' disease, the gland is hyperfunctioning and will show an **increased** (diffuse) uptake of iodine to synthesize more hormone [1]. * **T3 Resin Uptake (C):** This test indirectly measures the binding capacity of Thyroid Binding Globulin (TBG). In hyperthyroidism, since TBG binding sites are saturated with endogenous T3/T4, the resin uptake value is **increased**. **NEET-PG High-Yield Pearls:** * **Best Initial Test:** Serum TSH is the single most sensitive screening test for both hyper- and hypothyroidism [3]. * **Graves' Disease Triad:** Hyperthyroidism, Exophthalmos (Ophthalmopathy), and Pretibial Myxedema (Dermopathy) [2]. * **Apathetic Hyperthyroidism:** Seen in elderly patients where typical adrenergic symptoms (tachycardia, tremors) may be absent; they may present only with atrial fibrillation or weight loss. * **Subclinical Hyperthyroidism:** Defined as a low TSH with normal Free T4 and T3 levels [4].

Q: A 30-year-old female presents with a 3-month history of 10kg weight loss despite an increased appetite. She also complains of anxiety, diarrhea, and amenorrhea. Examination reveals a fine tremor, brisk reflexes, and a systolic murmur heard throughout the precordium. A urine pregnancy screen was negative. What is the most likely finding on examining the pulse?

Irregularly irregular pulse. The clinical presentation of weight loss despite increased appetite, anxiety, diarrhea, and amenorrhea in a young female is classic for **Hyperthyroidism** (likely Graves' disease) [1], [4]. The presence of a fine tremor, brisk reflexes, and a hyperdynamic precordium further supports this diagnosis [1]. **Why the correct answer is right:** Hyperthyroidism induces a hyperadrenergic state, increasing the sensitivity of the heart to catecholamines. This frequently leads to supraventricular tachyarrhythmias, most notably **Atrial Fibrillation (AF)** [2]. AF is characterized by an **irregularly irregular pulse** and a pulse deficit. While sinus tachycardia is the most common rhythm abnormality in thyrotoxicosis, AF occurs in approximately 10–15% of patients, especially if the hyperthyroidism is severe or long-standing [2], [3]. **Why the incorrect options are wrong:** * **Pulsus paradoxus:** Defined as an inspiratory drop in systolic BP >10 mmHg; it is seen in cardiac tamponade, severe asthma, or COPD. * **Collapsing pulse (Water-hammer pulse):** Associated with high-output states (like hyperthyroidism) and Aortic Regurgitation. While hyperthyroidism *can* cause a wide pulse pressure [1], the NEET-PG focus for "most likely finding" in the context of rhythm/examination often points toward the arrhythmia (AF). * **Pulsus alternans:** Alternating strong and weak beats; it is a hallmark of severe Left Ventricular Failure. **High-Yield Clinical Pearls for NEET-PG:** * **Most common arrhythmia in Hyperthyroidism:** Sinus Tachycardia [2]. * **Most common chronic arrhythmia in Hyperthyroidism:** Atrial Fibrillation [3]. * **Treatment of choice for symptoms:** Beta-blockers (Propranolol) as they inhibit peripheral conversion of T4 to T3 and control adrenergic symptoms [3], [5]. * **Auscultation:** A systolic murmur in hyperthyroidism is often a "Flow Murmur" due to the hyperdynamic circulation.

Q: True about Chvostek's sign are all of the following except?

Raised calcium level. Chvostek’s sign is a clinical indicator of latent tetany resulting from hypocalcemia (low serum calcium levels) [1]. 1. Why Option C is correct: The statement "Raised calcium level" is false. Chvostek’s sign is elicited when serum calcium levels are low. In hypocalcemia, the threshold for nerve depolarization is lowered, leading to neuromuscular hyperexcitability. High calcium levels (hypercalcemia) actually decrease neuromuscular excitability [1]. 2. Why other options are incorrect: * Option A: Hypocalcemia increases the permeability of neuronal membranes to sodium ions, causing spontaneous discharges or neuromuscular hyperexcitability. * Option B & D: The sign is elicited over the face by tapping the facial nerve at the angle of the jaw (anterior to the external auditory meatus). A positive result is characterized by twitching of the ipsilateral facial muscles (nose, mouth, or eye). High-Yield Clinical Pearls for NEET-PG: * Trousseau’s Sign: A more sensitive and specific sign for hypocalcemia than Chvostek’s. It involves inflating a BP cuff above systolic pressure for 3 minutes, resulting in carpopedal spasm (flexion of wrist/MCP joints, extension of IP joints, adduction of thumb). * Causes of Hypocalcemia: Hypoparathyroidism (often post-thyroidectomy), Vitamin D deficiency, Acute Pancreatitis, and Hypomagnesemia [1]. * False Positives: Chvostek’s sign can be present in approximately 10% of healthy individuals with normal calcium levels. * Management: Acute symptomatic tetany is treated with IV Calcium Gluconate.

Q: A 20-year-old male presents with chronic constipation, headache, characteristic habitus, neuromas of the tongue, medullated corneal nerve fibers, and a 2x2 cm nodule in the left lobe of the thyroid. What is the most likely diagnosis?

Multiple Endocrine Neoplasia (MEN) type 2B. ### Explanation The correct diagnosis is **Multiple Endocrine Neoplasia (MEN) type 2B**. This syndrome is characterized by the triad of Medullary Thyroid Carcinoma (MTC), Pheochromocytoma, and a distinct physical phenotype. **Why Option D is correct:** The patient exhibits pathognomonic features of MEN 2B: * **Mucosal Neuromas:** Present on the tongue, lips, and eyelids. * **Marfanoid Habitus:** Long limbs and characteristic body proportions (implied by "characteristic habitus"). * **Medullated Corneal Nerve Fibers:** A highly specific finding for MEN 2B. * **Gastrointestinal involvement:** Chronic constipation in these patients is often due to **intestinal ganglioneuromatosis**, which affects gut motility. * **Thyroid Nodule:** Represents Medullary Thyroid Carcinoma (MTC), which occurs in nearly 100% of these patients and is often aggressive [2]. **Why other options are incorrect:** * **Option A & B:** While MTC is present in both sporadic and familial forms, these do not present with marfanoid habitus, mucosal neuromas, or medullated corneal nerves. * **Option C (MEN 2A):** MEN 2A consists of MTC, Pheochromocytoma, and Parathyroid Hyperplasia. It lacks the mucosal neuromas and marfanoid features seen in MEN 2B [2]. **High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** Both MEN 2A and 2B are caused by germline mutations in the **RET proto-oncogene** [2]. * **MTC Aggression:** MTC in MEN 2B is more aggressive and occurs earlier than in MEN 2A; prophylactic thyroidectomy is often recommended in infancy [2]. * **Screening:** Always rule out **Pheochromocytoma** (check urinary metanephrines) before performing thyroid surgery to prevent a hypertensive crisis [1], [2]. * **MEN 2B Components:** MTC (100%), Pheochromocytoma (50%), Mucosal Neuromas/Marfanoid habitus (100%), and *rarely* Hyperparathyroidism (unlike MEN 2A).

Q: A 30-year-old pregnant woman presents for a routine physical examination. Her plasma levels of TSH are high, but her total thyroid hormone concentration is normal. Which of the following best reflects the patient's clinical state?

Hashimoto's disease. The patient presents with **elevated TSH** and **normal total thyroid hormone** levels. In pregnancy, high estrogen levels increase **Thyroxine-Binding Globulin (TBG)**, which normally leads to an increase in *total* T4/T3 to maintain normal *free* hormone levels. A "normal" total T4 in a pregnant patient is often inappropriately low, suggesting an underlying inability of the thyroid gland to meet the increased physiological demand. 1. **Why Hashimoto’s Disease is correct:** This clinical picture (High TSH, Normal/Low-Normal T4) represents **Subclinical Hypothyroidism** [1]. Hashimoto’s thyroiditis is the most common cause of primary hypothyroidism. In the early stages, the pituitary compensates for a failing thyroid by increasing TSH production to maintain thyroid hormone levels within the reference range [1]. 2. **Why the other options are incorrect:** * **Graves’ Disease:** Characterized by hyperthyroidism. TSH would be suppressed (low), and thyroid hormones (T4/T3) would be elevated [1]. * **Pituitary/Hypothalamic Tumors (Options C & D):** These cause **Secondary Hyperthyroidism**. While TSH would be high, the thyroid hormones (T4/T3) would also be significantly **elevated**, not normal, as the thyroid gland is being overstimulated [1]. **NEET-PG High-Yield Pearls:** * **Pregnancy & Thyroid:** Total T4/T3 levels increase by 1.5 times due to increased TBG. Therefore, a "normal" total T4 in pregnancy may actually indicate hypothyroidism. * **Subclinical Hypothyroidism:** Defined as Elevated TSH with Normal Free T4 [1]. * **Wolff-Chaikoff Effect:** Transient hypothyroidism caused by an iodine load (relevant as Hashimoto's patients are sensitive to iodine). * **Treatment Goal:** In pregnancy, TSH should ideally be maintained <2.5 mIU/L to prevent maternal and fetal complications.

Question 1

A short fourth metacarpal is a characteristic feature of which of the following conditions?

Accepted Answer

Pseudohypoparathyroidism

Answer

Hypothyroidism

Answer

Hyperthyroidism

Answer

Hypoparathyroidism

Question 2

A 35-year-old woman presents with amenorrhea and weight loss despite increased appetite. The history and physical examination reveal exophthalmos, fine resting tremor, tachycardia, and warm, moist skin. What laboratory test for thyroid function would be expected to yield a decreased value?

Accepted Answer

Thyroid stimulating hormone

Answer

Free T4

Answer

Radioactive iodine uptake

Answer

T3 resin uptake

Question 3

A 30-year-old female presents with a 3-month history of 10kg weight loss despite an increased appetite. She also complains of anxiety, diarrhea, and amenorrhea. Examination reveals a fine tremor, brisk reflexes, and a systolic murmur heard throughout the precordium. A urine pregnancy screen was negative. What is the most likely finding on examining the pulse?

Accepted Answer

Irregularly irregular pulse

Answer

Pulsus paradoxus

Answer

Collapsing pulse

Answer

Pulsus alternans

Question 4

Which of the following findings is most consistent with the diagnosis of subacute (De Quervain's) thyroiditis?

Accepted Answer

A 45-year-old male with a painful thyroid of 8 weeks duration, low free T4 and T3, and elevated TSH.

Answer

A 45-year-old female with a 2-week history of a painful thyroid gland, elevated T4 and T3, low TSH, and increased radioactive iodine uptake (RAIU).

Answer

A 25-year-old female with a painless enlarged thyroid, elevated T4 and T3, undetectable TSH, and increased RAIU.

Answer

A 45-year-old female with fatigue, low T4 and T3, and low TSH.

Question 5

A 53-year-old woman with metastatic breast cancer presents with lethargy, fatigue, and hypercalcemia, leading to a near-comatose state. After addressing airway, breathing, and circulation, what is the best initial therapy for this patient's hypercalcemia?

Accepted Answer

Saline infusion and furosemide

Answer

Bisphosphonates

Answer

IV estrogen therapy

Answer

Vitamin D

Question 6

True about Chvostek's sign are all of the following except?

Accepted Answer

Raised calcium level

Answer

Denotes neuromuscular hyperexcitability

Answer

Elicited over the face

Answer

Facial nerve is stimulated by tapping

Question 7

A 50-year-old man with a long-standing history of diabetes presents with a poor urinary stream, hesitancy, difficulty in micturition, and incomplete bladder emptying. What is the most likely diagnosis?

Accepted Answer

Autonomic neuropathy

Answer

Benign Prostatic Hyperplasia (BPH)

Answer

Urinary Tract Infection (UTI)

Answer

Atonic bladder

Question 8

A 20-year-old male presents with chronic constipation, headache, characteristic habitus, neuromas of the tongue, medullated corneal nerve fibers, and a 2x2 cm nodule in the left lobe of the thyroid. What is the most likely diagnosis?

Accepted Answer

Multiple Endocrine Neoplasia (MEN) type 2B

Answer

Sporadic medullary carcinoma of the thyroid

Answer

Familial medullary carcinoma of the thyroid

Answer

Multiple Endocrine Neoplasia (MEN) type 2A

Question 9

A 30-year-old pregnant woman presents for a routine physical examination. Her plasma levels of TSH are high, but her total thyroid hormone concentration is normal. Which of the following best reflects the patient's clinical state?

Accepted Answer

Hashimoto's disease

Answer

Graves' disease

Answer

A pituitary tumor secreting TSH

Answer

A hypothalamic tumor secreting thyrotropin-releasing hormone (TRH)

Question 10

Which of the following statements regarding thyrotoxicosis are true?

Accepted Answer

Statements 1, 2, 3, and 4 are true, while statement 5 is false.

Answer

Statements 1 and 2 are true, while statements 3, 4, and 5 are false.

Answer

Statements 3 and 4 are true, while statements 1, 2, and 5 are false.

Answer

Statements 4 and 5 are true, while statements 1, 2, and 3 are false.

Endocrinology — MCQs

Endocrinology — MCQs

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