Endocrinology Practice Questions

Q: A 60-year-old man with small cell carcinoma of the lung presents to the emergency room in a coma after a clonic-tonic seizure. His temperature is 37°C, blood pressure is 100/50 mm Hg, and pulse is 88 per minute. Laboratory studies show a serum sodium of 103 mmol/L, normal serum levels of BUN and creatinine, and a dilute but otherwise normal urine. A CT scan of the head is normal. What is the most likely cause of seizures in this patient?

Syndrome of inappropriate ADH secretion. The patient presents with severe hyponatremia (103 mmol/L) and neurological symptoms (coma, seizures) in the setting of Small Cell Carcinoma of the Lung (SCLC) [1]. This is a classic presentation of Syndrome of Inappropriate Antidiuretic Hormone (SIADH), a common paraneoplastic syndrome associated with SCLC [1]. Why SIADH is correct: In SIADH, ectopic production of ADH leads to excessive water reabsorption in the renal collecting ducts [4]. This results in euvolemic hyponatremia due to water retention and secondary natriuresis [3]. When serum sodium drops rapidly or falls below 120 mmol/L, it causes cerebral edema, leading to headache, confusion, seizures, and coma [2]. The normal BUN and creatinine levels support a non-renal, euvolemic state [3]. Why other options are incorrect: * Central Diabetes Insipidus: This involves a deficiency of ADH, leading to polyuria and hypernatremia, not hyponatremia. * Diabetes Mellitus: While severe hyperglycemia can cause osmotic diuresis or pseudohyponatremia, it would not typically present with a sodium level as low as 103 mmol/L without significant glucose elevation or ketoacidosis. * Renal Metastases: While possible in advanced cancer, they usually cause hematuria or renal failure (elevated BUN/Creatinine) rather than isolated, profound hyponatremia. NEET-PG High-Yield Pearls: * SCLC Associations: SIADH and Lambert-Eaton Myasthenic Syndrome are the most common paraneoplastic syndromes [1]. * Diagnosis of SIADH: Characterized by hyponatremia, low serum osmolality ( 100 mOsm/kg). * Management: For severe symptomatic hyponatremia (seizures/coma), the treatment of choice is Hypertonic Saline (3% NaCl). * Caution: Avoid rapid correction (>8–10 mmol/L in 24 hours) to prevent Osmotic Demyelination Syndrome (Central Pontine Myelinolysis) [5].

Q: Which of the following is NOT a complication arising out of the use of the medical device shown?

Peripheral neuropathy. ***Peripheral neuropathy*** - **Peripheral neuropathy** is a complication of **long-standing diabetes mellitus** caused by chronic hyperglycemia-induced nerve damage, not a direct complication of insulin pump use. - While poor glycemic control may contribute to neuropathy over time, the insulin pump device itself does not cause peripheral neuropathy, making this unrelated to pump-specific complications. *Lipo-hypertrophy* - **Repeated injections** at the same infusion site can cause **subcutaneous fat hypertrophy**, leading to lumpy skin areas. - This is a **common complication** of insulin pump therapy and affects **insulin absorption** at affected sites. *Neuro-glucopenia* - **Hypoglycemia** from insulin pump malfunction or incorrect dosing can cause **neuroglycopenic symptoms** like confusion, seizures, or coma. - This is a **serious complication** requiring immediate glucose administration and pump adjustment. *Hyperglycemia or ketoacidosis due to infusion-set interruption* - **Interruption of insulin delivery** due to infusion-set occlusion, kinking, or disconnection can rapidly lead to **hyperglycemia or diabetic ketoacidosis (DKA)**, as the patient has no subcutaneous insulin depot. - This is a **well-recognized complication** of insulin pump therapy directly attributable to the device and its infusion set.

Q: Which of the following can cause osteonecrosis?

Systemic Lupus Erythematosus (SLE). **Explanation:** **Osteonecrosis (Avascular Necrosis)** is the death of bone components due to an interruption of blood supply, most commonly affecting the femoral head. **Why SLE is the Correct Answer:** Systemic Lupus Erythematosus (SLE) is a major risk factor for osteonecrosis. The pathogenesis is multifactorial, involving **vasculitis**, secondary **antiphospholipid syndrome (APLS)** leading to thrombosis, and, most significantly, the chronic use of **high-dose corticosteroids** to manage the disease. In many clinical scenarios, SLE is considered an independent risk factor even when steroid doses are controlled. **Analysis of Other Options:** * **A. Sickle Cell Anemia:** While Sickle Cell Anemia is a classic cause of osteonecrosis (due to vaso-occlusive crises), in the context of this specific question format, SLE is often highlighted as the systemic autoimmune prototype. However, it is important to note that both A and B are technically well-known causes. * **B. Corticosteroid Use:** This is the **most common** non-traumatic cause of osteonecrosis. It induces fat hypertrophy in the marrow, increasing intraosseous pressure and reducing blood flow. * **C. Diabetes Mellitus:** While DM causes various bone pathologies (like Charcot joint), it is **not** a direct or primary cause of osteonecrosis. **NEET-PG High-Yield Pearls:** * **Most common site:** Femoral head (due to retrograde blood supply via the medial circumflex femoral artery). * **Imaging of choice:** **MRI** is the most sensitive investigation for early detection (shows "double line sign"). * **X-ray finding:** "Crescent sign" (subchondral collapse) is a late finding. * **Mnemonic for Causes (PLASTIC RAGS):** **P**ancreatitis, **L**upus (SLE), **A**lcohol, **S**ickle cell, **T**rauma, **I**diopathic, **C**aisson disease, **R**adiation, **A**myloidosis, **G**aucher disease, **S**teroids.

Q: Intractable peptic ulceration with renal stones occurs in which condition?

MEN I syndrome. **Explanation:** The correct answer is **MEN I syndrome** (Wermer’s syndrome). This condition is characterized by the "3 Ps": **P**ituitary adenoma, **P**arathyroid hyperplasia/adenoma, and **P**ancreatic islet cell tumors. 1. **Why MEN I is correct:** The patient presents with two distinct pathologies: * **Intractable peptic ulceration:** Caused by a **Gastrinoma** (a pancreatic neuroendocrine tumor), which leads to Zollinger-Ellison Syndrome (ZES). * **Renal stones:** Caused by **Primary Hyperparathyroidism**, which leads to hypercalcemia and hypercalciuria, resulting in nephrolithiasis. The coexistence of these two features specifically points toward the multi-glandular involvement seen in MEN I. 2. **Why other options are incorrect:** * **Zollinger-Ellison Syndrome (A):** While ZES explains the intractable ulcers, it does not inherently cause renal stones unless it is part of MEN I. * **Parathyroid Adenoma (B):** This explains the renal stones (via hypercalcemia) but does not cause intractable peptic ulcers (though hypercalcemia can mildly increase gastrin, it rarely causes "intractable" ulceration). * **Milk-Alkali Syndrome (C):** This presents with the triad of hypercalcemia, metabolic alkalosis, and renal failure due to excessive ingestion of calcium and absorbable alkali. It does not typically cause intractable ulceration. **Clinical Pearls for NEET-PG:** * **MEN I Inheritance:** Autosomal Dominant; mutation in the *MEN1* gene (encoding the protein Menin) on Chromosome 11q13. * **Most common presentation:** Hyperparathyroidism is usually the first clinical manifestation (95% of cases). * **ZES in MEN I:** Gastrinomas in MEN I are often multiple and located in the duodenum rather than the pancreas. * **Screening:** If a patient presents with ZES, always screen for MEN I by checking serum calcium and PTH levels.

Q: The triad of diabetes mellitus, gallstones, and steatorrhea is associated with which of the following tumors?

Somatostatinomas. The correct answer is **Somatostatinomas**. These are rare neuroendocrine tumors (NETs) of the pancreas or duodenum that secrete excessive amounts of somatostatin. **Why Somatostatinomas?** Somatostatin is a potent "inhibitory" hormone [1]. Its excess leads to the classic clinical triad through the following mechanisms: 1. **Diabetes Mellitus:** Somatostatin inhibits the release of insulin and glucagon [1]. 2. **Gallstones (Cholelithiasis):** It inhibits the release of Cholecystokinin (CCK) and reduces gallbladder contractility, leading to bile stasis. 3. **Steatorrhea:** It inhibits the secretion of pancreatic enzymes and bicarbonate, leading to fat malabsorption. **Incorrect Options:** * **Gastrinomas (Zollinger-Ellison Syndrome):** Characterized by excessive gastrin, leading to refractory peptic ulcers and secretory diarrhea (due to gastric acid inactivating pancreatic lipases). * **VIPomas (Verner-Morrison Syndrome):** Characterized by **WDHA syndrome**: Watery Diarrhea, Hypokalemia, and Achlorhydria (also known as "Pancreatic Cholera"). * **Glucagonomas:** Characterized by the **4Ds**: Diabetes, Dermatitis (**Necrolytic Migratory Erythema**), Deep vein thrombosis, and Depression. **High-Yield Clinical Pearls for NEET-PG:** * **Location:** Most somatostatinomas are found in the **head of the pancreas** or the **duodenum** (often associated with NF-1). * **Psammoma Bodies:** Duodenal somatostatinomas are unique among NETs for frequently showing psammoma bodies on histology. * **Diagnosis:** Elevated fasting plasma somatostatin levels. * **Management:** Surgical resection is the treatment of choice; octreotide (a somatostatin analog) can paradoxically be used for symptom control in other NETs but is not the primary treatment here.

Q: All of the following statements regarding Craniopharyngiomas are true, except:

Usually intrasellar in location. Craniopharyngiomas are benign but locally aggressive tumors that account for about 3-5% of all intracranial tumors. **1. Why Option D is the Correct Answer (The False Statement):** Craniopharyngiomas are **primarily suprasellar** in location (about 75-90% of cases). While they can have an intrasellar component, a purely intrasellar craniopharyngioma is rare. They typically arise along the pituitary stalk and expand into the suprasellar cistern, often compressing the optic chiasm and hypothalamus [1]. **2. Analysis of Other Options:** * **Option A (True):** These tumors are derived from the remnants of **Rathke’s pouch** (ectodermal origin), which is the same embryological precursor as the anterior pituitary gland [1]. * **Option B (True):** Due to their suprasellar location, they frequently compress the **optic chiasm**, leading to visual field defects, most classically **bitemporal hemianopia** [1]. * **Option C (True):** In adults, the gradual expansion of the tumor compresses the normal pituitary gland or stalk, leading to **hypopituitarism** (growth hormone deficiency is most common, followed by gonadotropin deficiency). **Clinical Pearls for NEET-PG:** * **Bimodal Age Distribution:** Peaks at 5–14 years and 50–75 years [1]. * **Imaging Triad:** Suprasellar mass showing **calcification** (very common in children), **cystic components** (filled with "machinery oil" fluid), and **solid enhancement** [1]. * **Histology:** Two types—**Adamantinomatous** (common in children, shows "wet keratin" and calcification) and **Papillary** (common in adults, lacks calcification). * **Clinical Presentation:** Often presents with the triad of headaches, visual disturbances, and endocrine dysfunction (including Diabetes Insipidus) [1].

Q: A 42-year-old male has a strongly positive Benedict's test, random blood sugar is > 163 mg%, and fasting blood sugar is > 200 mg%. What is the next line of investigation?

Oral glucose tolerance test (OGTT). ### Explanation **1. Why the Correct Answer (B) is Right:** The patient presents with symptoms and biochemical findings suggestive of Diabetes Mellitus (DM). However, the values provided are borderline or inconsistent with standard diagnostic criteria (e.g., a Fasting Blood Sugar (FBS) of >200 mg/dL is diagnostic, but a Random Blood Sugar (RBS) of >163 mg/dL is not). According to the **WHO and ADA guidelines**, when blood glucose levels are equivocal or do not clearly meet the diagnostic threshold for DM (FBS ≥126 mg/dL or RBS/2-hour post-load ≥200 mg/dL), the **Oral Glucose Tolerance Test (OGTT)** is the gold standard for confirmation [1]. It assesses the body's ability to handle a standardized glucose load (75g) and helps differentiate between Impaired Glucose Tolerance (IGT) and overt Diabetes Mellitus. **2. Why the Other Options are Incorrect:** * **A & D (Urine Glucose Estimation):** Benedict’s test and urine sugar levels are poor diagnostic tools for DM. The **renal threshold for glucose** is approximately 180 mg/dL; glucose only appears in urine once this is exceeded. Furthermore, urine testing cannot distinguish between DM and renal glycosuria. * **C (Repeat Benedict’s Test):** Benedict’s test is a non-specific semi-quantitative test for reducing sugars. Repeating it adds no diagnostic value to the management of hyperglycemia. **3. Clinical Pearls for NEET-PG:** * **Diagnostic Criteria for DM:** * FBS ≥ 126 mg/dL [1] * 2-hour OGTT (75g) ≥ 200 mg/dL * HbA1c ≥ 6.5% * Random Plasma Glucose ≥ 200 mg/dL (with classic symptoms of hyperglycemia). * **Benedict’s Test:** It detects reducing sugars (Glucose, Fructose, Lactose, Maltose, Galactose). It is **negative** for Sucrose (non-reducing). * **Renal Glycosuria:** Presence of glucose in urine despite normal blood glucose levels (seen in pregnancy or Fanconi syndrome).

Q: A 55-year-old male patient underwent cholecystectomy for gallstone calculus. During surgery, the patient's pulse was irregularly irregular, 160/min, BP = 80/50 mm of Hg, and temperature was 40°C. On examination, a swelling in the neck was found. What is the most likely diagnosis?

Thyroid storm. **Explanation:** The clinical presentation described—**hyperpyrexia (40°C)**, **tachyarrhythmia** (irregularly irregular pulse of 160/min, likely Atrial Fibrillation), and **hemodynamic instability** (BP 80/50 mmHg) in the presence of a **neck swelling** (goiter)—is a classic triad for **Thyroid Storm**. Thyroid storm is a life-threatening exacerbation of hyperthyroidism. In this case, the stress of surgery (cholecystectomy) acted as the precipitating factor. The "irregularly irregular" pulse indicates Atrial Fibrillation, a common complication of thyrotoxicosis due to increased sensitivity to catecholamines. **Why other options are incorrect:** * **Myocardial Infarction:** While it can cause hypotension and tachycardia, it does not typically present with high-grade fever (40°C) or a neck swelling. * **Arrhythmia:** This is a *finding* (symptom) in this case, not the primary diagnosis. The arrhythmia is secondary to the underlying thyrotoxic state. * **Stridor:** This is a physical sign of upper airway obstruction (often post-thyroidectomy due to nerve injury or hematoma) and does not explain the systemic symptoms of fever and hypotension. **NEET-PG High-Yield Pearls:** * **Precipitating factors:** Infection, trauma, surgery (especially in undiagnosed hyperthyroid patients), or DKA. * **Burch-Wartofsky Point Scale:** Used to diagnose Thyroid Storm based on thermoregulatory dysfunction, CNS effects, GI-hepatic dysfunction, and cardiovascular status. * **Management (The "P"s):** **P**ropylthiouracil (blocks synthesis and peripheral T4 to T3 conversion), **P**ropanolol (beta-blockade), **P**otassium Iodide (Lugol’s iodine to block hormone release), and **P**rednisolone (steroids).

Q: A 42-year-old man presents with dizziness on standing. His systolic blood pressure falls by 50 mm Hg and his heart rate is 52/min. What is the likely cause?

Pheochromocytoma. **Explanation:** The clinical presentation describes **orthostatic hypotension** (a drop in systolic BP ≥20 mmHg) accompanied by **inappropriate bradycardia** (lack of compensatory tachycardia) [1]. In **Pheochromocytoma**, while the classic triad is headache, sweating, and palpitations, chronic excess of catecholamines leads to severe **volume depletion** due to pressure natriuresis and chronic vasoconstriction. When the patient stands, the depleted intravascular volume causes a significant drop in blood pressure [2]. The presence of bradycardia (or a lack of tachycardia) in this context is a high-yield NEET-PG finding, often attributed to **baroreceptor resetting** or catecholamine-induced cardiomyopathy/autonomic dysfunction [3]. **Analysis of Incorrect Options:** * **Congestive Heart Failure (CHF):** While CHF can cause hypotension, it typically presents with compensatory tachycardia and signs of fluid overload (edema, JVP elevation), not bradycardia. * **Inferior Wall MI:** While this can cause bradycardia (due to Bezold-Jarisch reflex or SA/AV node ischemia), it presents with acute chest pain and ECG changes, and orthostatic hypotension is not the primary presenting feature. * **Theophylline Toxicity:** This typically causes **tachycardia**, arrhythmias, and seizures due to its phosphodiesterase inhibition and adenosine antagonism. **NEET-PG Clinical Pearls:** * **Rule of 10s for Pheo:** 10% bilateral, 10% malignant, 10% extra-adrenal (Paraganglioma), 10% pediatric, 10% familial. * **Orthostatic Hypotension in Pheo:** Paradoxically, a patient with hypertension who also shows orthostatic hypotension is a classic clue for Pheochromocytoma. * **Pre-op Management:** Always give **Alpha-blockers first** (e.g., Phenoxybenzamine) followed by Beta-blockers to avoid an uninhibited alpha-mediated hypertensive crisis.

Question 1

A 60-year-old man with small cell carcinoma of the lung presents to the emergency room in a coma after a clonic-tonic seizure. His temperature is 37°C, blood pressure is 100/50 mm Hg, and pulse is 88 per minute. Laboratory studies show a serum sodium of 103 mmol/L, normal serum levels of BUN and creatinine, and a dilute but otherwise normal urine. A CT scan of the head is normal. What is the most likely cause of seizures in this patient?

Accepted Answer

Syndrome of inappropriate ADH secretion

Answer

Central diabetes insipidus

Answer

Diabetes mellitus

Answer

Renal metastases

Question 2

A 40-year-old lady presents with weight loss and palpitations, having a heart rate of 110/min, BP 130/70 mmHg, bilateral proptosis, and warm, moist skin. Investigations show undetectable TSH and normal free T4. What is the next best step in diagnosis?

Accepted Answer

Free T3 levels

Answer

Radioactive iodine uptake scan

Answer

Thyroid peroxidase antibody screen

Answer

Thyroid stimulating antibody screen

Question 3

Which of the following is NOT a complication arising out of the use of the medical device shown?

Accepted Answer

Peripheral neuropathy

Answer

Lipo-hypertrophy

Answer

Hyperglycemia or ketoacidosis due to infusion-set interruption

Answer

Neuro-glucopenia

Question 4

Which of the following can cause osteonecrosis?

Accepted Answer

Systemic Lupus Erythematosus (SLE)

Answer

Sickle cell anemia

Answer

Corticosteroid use

Answer

Diabetes Mellitus

Question 5

Intractable peptic ulceration with renal stones occurs in which condition?

Accepted Answer

MEN I syndrome

Answer

Zollinger Ellison syndrome

Answer

Parathyroid adenoma

Answer

Milk, alkali syndrome

Question 6

The triad of diabetes mellitus, gallstones, and steatorrhea is associated with which of the following tumors?

Accepted Answer

Somatostatinomas

Answer

Gastrinomas

Answer

Vipomas

Answer

Glucagonomas

Question 7

All of the following statements regarding Craniopharyngiomas are true, except:

Accepted Answer

Usually intrasellar in location

Answer

Arise from Rathke's pouch

Answer

Can cause visual disturbances

Answer

Presents with hypopituitarism in adults

Question 8

A 42-year-old male has a strongly positive Benedict's test, random blood sugar is > 163 mg%, and fasting blood sugar is > 200 mg%. What is the next line of investigation?

Accepted Answer

Oral glucose tolerance test (OGTT)

Answer

Urine glucose estimation hourly for 5 hours

Answer

Repeat Benedict's test

Answer

24-hour urine sugar estimation

Question 9

A 55-year-old male patient underwent cholecystectomy for gallstone calculus. During surgery, the patient's pulse was irregularly irregular, 160/min, BP = 80/50 mm of Hg, and temperature was 40°C. On examination, a swelling in the neck was found. What is the most likely diagnosis?

Accepted Answer

Thyroid storm

Answer

Myocardial infarction

Answer

Arrhythmia

Answer

Stridor

Question 10

A 42-year-old man presents with dizziness on standing. His systolic blood pressure falls by 50 mm Hg and his heart rate is 52/min. What is the likely cause?

Accepted Answer

Pheochromocytoma

Answer

Congestive heart failure

Answer

Inferior wall myocardial infarction

Answer

Theophylline toxicity

Endocrinology — MCQs

Endocrinology — MCQs

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