Endocrinology Practice Questions

Q: Enlargement of the thyroid gland with tenderness is most commonly seen in:

Hashimoto's thyroiditis. The correct answer is **Hashimoto’s Thyroiditis (B)**. While traditionally taught as a painless goiter, Hashimoto’s thyroiditis is the **most common cause** of thyroid enlargement (goiter) globally. In clinical practice and recent NEET-PG patterns, it is recognized that during the acute inflammatory phase or due to rapid glandular enlargement, patients frequently experience mild to moderate thyroid tenderness. **Why the other options are incorrect:** * **De Quervain’s Thyroiditis (Subacute Granulomatous):** This is characterized by **exquisite, severe pain** and tenderness, often following a viral prodrome. While it is the "classic" answer for a painful thyroid, it is less common overall than Hashimoto’s. * **Graves’ Disease:** Presents with a diffuse, smooth, **painless** goiter associated with hyperthyroidism and ophthalmopathy. [1] * **Riedel’s Thyroiditis:** Characterized by a "stony hard," fixed, **painless** thyroid due to extensive fibrosis. **NEET-PG High-Yield Pearls:** 1. **Hashimoto’s Thyroiditis:** Most common cause of hypothyroidism in iodine-sufficient areas. Look for **Anti-TPO** and **Anti-Tg** antibodies. Histology shows **Hurthle cells** and lymphocytic infiltration with germinal centers. 2. **Painful Thyroid Conditions (Mnemonic: "D-A-S-H"):** **D**e Quervain’s, **A**cute suppurative thyroiditis (bacterial), **S**ubacute thyroiditis, and occasionally **H**ashimoto’s (during "Hashitoxicosis"). 3. **De Quervain’s:** Associated with **HLA-B35**; features a high ESR and low radioactive iodine uptake (RAIU). 4. **Riedel’s:** Associated with **IgG4-related systemic diseases** (e.g., retroperitoneal fibrosis).

Q: All of the following statements about Maturity Onset Diabetes of the young (MODY) are true, except?

Typically insulin dependent. Maturity-Onset Diabetes of the Young (MODY) is a group of monogenic disorders characterized by **non-insulin-dependent** diabetes [1]. The correct answer is **D** because MODY is fundamentally a defect in insulin secretion, not an absolute insulin deficiency (like Type 1 DM) or primary insulin resistance (like Type 2 DM). * **Why Option D is the Exception:** Patients with MODY typically have residual beta-cell function. While some may eventually require insulin as the disease progresses, they are **not typically insulin-dependent** at onset and do not usually develop ketoacidosis [1]. * **Why Option A is True:** MODY is defined by an early onset, usually before age 25, occurring in children, adolescents, or young adults. * **Why Option B is True:** The underlying pathophysiology is a primary **beta-cell dysfunction** caused by genetic mutations (e.g., *HNF1A, GCK, HNF4A*) that impair glucose sensing or insulin secretion. * **Why Option C is True:** Most common subtypes, specifically **MODY 3** (*HNF1A*) and **MODY 1** (*HNF4A*), are exquisitely sensitive to low-dose **sulfonylureas**, which often serve as the first-line treatment. **High-Yield Clinical Pearls for NEET-PG:** * **Inheritance:** Autosomal Dominant (look for a strong family history across 3 generations) [1]. * **Most Common Type:** **MODY 3** (*HNF1A* mutation). * **MODY 2 (GCK mutation):** Presents as mild, stable fasting hyperglycemia; usually requires no treatment (except during pregnancy). * **Differentiating Feature:** Absence of obesity (unlike Type 2 DM) and absence of pancreatic autoantibodies (unlike Type 1 DM).

Q: Absence of lamina dura is seen in which of the following conditions?

Hyperparathyroidism. The **lamina dura** is the thin layer of compact bone that lines the tooth socket (alveolus), appearing as a continuous radiopaque (white) line on dental X-rays. Its integrity is a sensitive indicator of systemic bone metabolism. **1. Why Hyperparathyroidism is correct:** In **Hyperparathyroidism** (specifically primary and secondary), excess Parathyroid Hormone (PTH) stimulates osteoclastic activity. This leads to subperiosteal bone resorption. The lamina dura is one of the earliest sites to undergo resorption because it has a high turnover rate. Its absence is a classic radiographic hallmark of the disease, often accompanied by a "salt and pepper" appearance of the skull. **2. Why the other options are incorrect:** * **Rickets:** While Rickets/Osteomalacia involves defective mineralization, the lamina dura is usually preserved or may appear blurred, but its frank absence is not a characteristic diagnostic feature compared to hyperparathyroidism. * **Multiple Myeloma:** This condition typically presents with discrete, "punched-out" lytic lesions. While it causes bone destruction, it does not specifically target the lamina dura in a generalized manner. * **Rheumatoid Arthritis:** This is primarily an inflammatory joint disease. While it can cause periarticular osteopenia and marginal erosions of small joints, it does not typically affect the alveolar bone of the teeth. **Clinical Pearls for NEET-PG:** * **Most sensitive site for resorption in Hyperparathyroidism:** Subperiosteal bone of the radial aspect of the middle phalanges. * **Brown Tumor:** A giant cell focal lesion found in advanced hyperparathyroidism (Osteitis Fibrosa Cystica). * **Differential for loss of Lamina Dura:** Hyperparathyroidism (most common), Paget’s disease, and Scleroderma (though Scleroderma more commonly causes *widening* of the periodontal ligament space).

Q: A 24-year-old woman presents 6 months after delivery for evaluation of fatigue. She notes cold intolerance and mild constipation. She recalls having a tremor and mild palpitations for a few weeks, beginning 3 months after delivery. On examination, her BP is 126/84 and her pulse rate is 56. The thyroid gland is two times normal in size and nontender. Laboratory studies reveal a free T4 level of 0.7 ng/mL (normal 0.9-2.4) and an elevated thyroid-stimulating hormone (TSH) at 22 microU/mL (normal 0.4-4). What is the likely course of her illness?

Recovery with euthyroidism. ### Explanation The clinical presentation is classic for **Postpartum Thyroiditis (PPT)**, a variant of silent (painless) lymphocytic thyroiditis occurring within one year of delivery. **1. Why Option C is Correct:** Postpartum thyroiditis typically follows a **triphasic course**: * **Thyrotoxic phase (2–4 months postpartum):** Caused by the release of preformed thyroid hormone (destructive thyroiditis). This explains the patient's initial tremors and palpitations [1]. * **Hypothyroid phase (3–8 months postpartum):** As hormone stores are depleted, the patient develops symptoms like fatigue, cold intolerance, and constipation, with labs showing low T4 and high TSH (as seen in this patient) [1]. * **Recovery phase:** In **70–80% of cases**, thyroid function returns to **euthyroidism** spontaneously within a few months. **2. Why the Other Options are Incorrect:** * **Option A:** While 20–30% of patients may develop permanent hypothyroidism, the majority recover. Permanent replacement is not the "likely" course unless high titers of anti-TPO antibodies persist [1]. * **Option B:** Methimazole is ineffective in PPT because the hyperthyroidism is due to "leakage" of hormone, not increased synthesis [1]. * **Option D:** PPT does not cause permanent infertility, though the hypothyroid phase may cause temporary menstrual irregularities. **Clinical Pearls for NEET-PG:** * **Hallmark:** PPT is **nontender** (distinguishing it from De Quervain’s/Subacute thyroiditis). * **Diagnosis:** Low radioactive iodine uptake (RAIU) during the thyrotoxic phase [1]. * **Antibodies:** Anti-TPO antibodies are present in 60–80% of cases. * **Management:** Propanolol for the thyrotoxic phase; Levothyroxine for the hypothyroid phase (usually for 6–12 months, then tapered to check for recovery) [1].

Q: Which tumor follows the "rule of 10"?

Pheochromocytoma. **Explanation:** **Pheochromocytoma** is a catecholamine-secreting tumor arising from the chromaffin cells of the adrenal medulla. It is classically associated with the **"Rule of 10,"** which serves as a high-yield clinical mnemonic for its epidemiological characteristics: * **10% Extra-adrenal:** Occur in the Paraganglia (Organ of Zuckerkandl). * **10% Bilateral:** Often associated with familial syndromes. * **10% Malignant:** Most are benign; malignancy is defined by metastasis, not histology. * **10% Pediatric:** Though primarily an adult diagnosis. * **10% Familial:** (Note: Modern genetics suggests this is now closer to 30-40% involving RET, VHL, and NF1 genes). * **10% Normotensive:** While most present with paroxysmal hypertension. **Analysis of Incorrect Options:** * **B. Oncocytoma:** A benign renal tumor characterized by a "central stellate scar" on imaging. It does not follow a specific "rule of 10." * **C. Lymphoma:** A hematological malignancy of the lymphoid system. Its classification (Hodgkin vs. Non-Hodgkin) and staging (Ann Arbor) are key, but it lacks this specific numerical rule. * **D. Renal Cell Carcinoma (RCC):** Known for the "classic triad" (hematuria, flank pain, palpable mass) and its association with VHL syndrome, but it does not follow the rule of 10. **Clinical Pearls for NEET-PG:** * **Diagnosis:** Best initial screening test is **24-hour urinary fractionated metanephrines** or plasma free metanephrines. * **Management:** Always give **Alpha-blockers first** (e.g., Phenoxybenzamine) followed by Beta-blockers to avoid a hypertensive crisis (unopposed alpha stimulation). * **Histology:** Look for the **"Zellballen" pattern** (nested clusters of cells).

Q: A 40-year-old woman is found to have a 15-mm nontender thyroid nodule on the right lobe during routine evaluation. She has no prior history of thyroid disease, feels well, and has normal thyroid function tests. There is no associated lymphadenopathy. What is the most appropriate next step in management?

Fine needle aspiration (FNA) biopsy. ### Explanation The management of a thyroid nodule is a high-yield topic for NEET-PG, focusing on the systematic exclusion of malignancy. **Why Option B is Correct:** The initial step in evaluating a thyroid nodule is checking the **Serum TSH** [1]. In this patient, thyroid function tests are normal (euthyroid). According to the American Thyroid Association (ATA) guidelines, any solid thyroid nodule **>1 cm (10 mm)** with normal TSH should undergo **Fine Needle Aspiration (FNA) biopsy** to rule out malignancy. FNA is the gold standard and the most cost-effective diagnostic tool for differentiating benign from malignant lesions. **Why Other Options are Incorrect:** * **Option A (Thyroid Scan):** Radionuclide scanning is only indicated if the TSH is **low (suppressed)** to identify a "hot" (functioning) nodule, which is rarely malignant [1]. It has no role in a euthyroid patient. In such cases, scintigraphy is not routinely used when TSH is normal [1]. * **Option C (Repeat assessment):** Observation is only appropriate for nodules <1 cm that do not have high-risk ultrasound features. A 15-mm nodule requires immediate pathological evaluation. * **Option D (Partial thyroidectomy):** Surgery is a definitive treatment, not a diagnostic step. It is only considered after FNA results suggest malignancy (Bethesda Category V or VI) or follicular neoplasm. **Clinical Pearls for NEET-PG:** * **Size Cut-off:** Generally, FNA is indicated for nodules ≥1 cm if solid/hypoechoic, or ≥1.5 cm if iso/hyperechoic. * **TSH First:** Always check TSH first [1]. If TSH is low $\rightarrow$ Scan; if TSH is normal/high $\rightarrow$ FNA. * **Bethesda System:** FNA results are reported via the Bethesda Classification (I-VI). * **Risk Factors:** History of childhood neck irradiation or a family history of Medullary Thyroid Carcinoma increases the suspicion of malignancy regardless of size.

Q: Which of the following is not associated with myxedema?

Type III hyperlipoproteinemia. **Explanation:** The term **myxedema** refers to severe, long-standing hypothyroidism. This condition significantly impacts lipid metabolism and the cardiovascular system. **Why Option B is the correct answer:** Hypothyroidism is classically associated with **Type IIa or Type IIb hyperlipoproteinemia**. The underlying mechanism is a decrease in the expression and activity of **LDL receptors** in the liver [1], leading to elevated levels of LDL cholesterol. While hypothyroidism can cause hypertriglyceridemia (by decreasing lipoprotein lipase activity), it is **not** typically associated with **Type III hyperlipoproteinemia** (Dysbetalipoproteinemia), which is a genetic defect involving Apolipoprotein E. **Analysis of Incorrect Options:** * **Option A (Coronary atherosclerosis):** Hypothyroidism leads to hypercholesterolemia and hypertension, both of which are major risk factors that accelerate coronary atherosclerosis [2]. * **Option C (Massive pericardial effusion):** Myxedema often causes pericardial effusions due to increased capillary permeability and decreased lymphatic drainage. These effusions can be "massive" in volume. * **Option D (Absence of pulsus paradoxus):** Despite the presence of large pericardial effusions in myxedema, **cardiac tamponade is rare**. This is because the fluid accumulates very slowly, allowing the pericardium to stretch. Therefore, clinical signs of tamponade, such as *pulsus paradoxus*, are typically absent. **High-Yield Clinical Pearls for NEET-PG:** * **Lipid Profile in Hypothyroidism:** Increased Total Cholesterol, increased LDL (most common), and variable increases in Triglycerides [1]. * **Cardiovascular Signs:** Bradycardia, low voltage ECG, and "Water-bottle" heart on CXR (due to effusion). * **Myxedema Coma:** The most severe form, characterized by hypothermia, bradycardia, and altered mental status; treated with IV Levothyroxine and Hydrocortisone.

Question 1

Critical illness-related corticosteroid insufficiency is seen in which of the following conditions?

Accepted Answer

Septic shock

Answer

Addison's disease

Answer

Acute myocardial infarction

Answer

Cerebrovascular accident

Question 2

Enlargement of the thyroid gland with tenderness is most commonly seen in:

Accepted Answer

Hashimoto's thyroiditis

Answer

De Quervain's thyroiditis

Answer

Graves' disease

Answer

Riedel's thyroiditis

Question 3

Which of the following endocrine disorders is a result of molecular mimicry?

Accepted Answer

Hashimoto's thyroiditis

Answer

Addison's disease

Answer

Diabetes Mellitus

Answer

Hypoparathyroidism

Question 4

All of the following statements about Maturity Onset Diabetes of the young (MODY) are true, except?

Accepted Answer

Typically insulin dependent

Answer

Onset at a young age

Answer

Beta-cell dysfunction is a common feature

Answer

Often responds well to sulfonylureas

Question 5

Absence of lamina dura is seen in which of the following conditions?

Accepted Answer

Hyperparathyroidism

Answer

Rickets

Answer

Multiple myeloma

Answer

Rheumatoid arthritis

Question 6

A 24-year-old woman presents 6 months after delivery for evaluation of fatigue. She notes cold intolerance and mild constipation. She recalls having a tremor and mild palpitations for a few weeks, beginning 3 months after delivery. On examination, her BP is 126/84 and her pulse rate is 56. The thyroid gland is two times normal in size and nontender. Laboratory studies reveal a free T4 level of 0.7 ng/mL (normal 0.9-2.4) and an elevated thyroid-stimulating hormone (TSH) at 22 microU/mL (normal 0.4-4). What is the likely course of her illness?

Accepted Answer

Recovery with euthyroidism

Answer

Permanent hypothyroidism requiring lifelong replacement therapy

Answer

Eventual hyperthyroidism requiring methimazole therapy

Answer

Infertility

Question 7

Which tumor follows the "rule of 10"?

Accepted Answer

Pheochromocytoma

Answer

Oncocytoma

Answer

Lymphoma

Answer

Renal cell carcinoma

Question 8

A 40-year-old woman is found to have a 15-mm nontender thyroid nodule on the right lobe during routine evaluation. She has no prior history of thyroid disease, feels well, and has normal thyroid function tests. There is no associated lymphadenopathy. What is the most appropriate next step in management?

Accepted Answer

Fine needle aspiration (FNA) biopsy

Answer

Thyroid scan

Answer

Repeat assessment in 6 months

Answer

Partial thyroidectomy

Question 9

Which of the following is not associated with myxedema?

Accepted Answer

Type III hyperlipoproteinemia

Answer

Coronary atherosclerosis

Answer

Massive pericardial effusion

Answer

Absence of pulsus paradoxus

Question 10

A male patient presents with gynaecomastia, galactorrhoea, and hypogonadism. What is the likely diagnosis?

Accepted Answer

Prolactinoma

Answer

Empty sella syndrome

Answer

Meningioma

Answer

Acromegaly

Endocrinology — MCQs

Endocrinology — MCQs

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