Endocrinology Practice Questions

Q: A 25-year-old man presents with a confused state, intense headache, profuse sweating, and eye rolling. His wife reports similar past events that resolved spontaneously. He smokes 20 packs of cigarettes per year and drinks 2-3 beers on weekends. On examination, he is confused, obeys simple commands, has intact deep tendon reflexes, and vital signs show BP 210/108 mm Hg and pulse 124/min. Laboratory results are: Na+ 142 meq/L, K+ 3.8 meq/L, BUN 30 mg/dL, S creatinine 1.0 mg/dL, and Blood sugar 110 mg/dL. What medication should be started preoperatively given the patient's condition?

Phenoxybenzamine and propranolol. ### **Explanation** The clinical presentation—episodic headache, profuse sweating, palpitations (tachycardia), and severe hypertension (210/108 mmHg)—is the classic triad of **Pheochromocytoma**. The "eye rolling" and confusion represent hypertensive encephalopathy or transient neurological symptoms during a paroxysm. **1. Why Option D is Correct:** The cornerstone of preoperative management for pheochromocytoma is **combined alpha and beta-adrenergic blockade** [1]. * **Phenoxybenzamine** (an irreversible, non-selective alpha-blocker) is started first to control hypertension and expand the contracted intravascular volume [1]. * **Propranolol** (a beta-blocker) is added only **after** adequate alpha-blockade is achieved to manage tachycardia or arrhythmias. **2. Why Other Options are Incorrect:** * **Option A:** Phentolamine is a short-acting alpha-blocker used for hypertensive crises, but it is not the standard long-term preoperative oral regimen. Using two alpha-blockers together is redundant. * **Option B:** Giving a beta-blocker alone is **contraindicated**. Blocking vasodilatory beta-2 receptors while alpha-1 receptors are unopposed leads to "unopposed alpha stimulation," causing a catastrophic rise in blood pressure. [1] * **Option C:** Nitroglycerine is a vasodilator used in acute hypertensive emergencies but does not address the underlying catecholamine excess required for surgical stabilization. **3. Clinical Pearls for NEET-PG:** * **Rule of 10s:** 10% bilateral, 10% malignant, 10% extra-adrenal (Paraganglioma), 10% pediatric, 10% familial. * **Sequence Matters:** Always **Alpha before Beta** (usually 7–14 days before surgery) [1]. * **Diagnosis:** Best initial screening test is **Plasma free metanephrines**; most specific is **24-hour urinary catecholamines/metanephrines**. * **Associated Syndromes:** MEN 2A, MEN 2B, von Hippel-Lindau (VHL), and Neurofibromatosis type 1 (NF1). [1]

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: In Acromegaly, which of the following is NOT typically seen?

Decreased sweating. In Acromegaly, the clinical presentation is driven by the chronic hypersecretion of **Growth Hormone (GH)** and its mediator, **IGF-1**, leading to widespread anabolic effects [1]. ### **Why "Decreased Sweating" is the Correct Answer** In Acromegaly, patients actually experience **increased sweating (hyperhidrosis)** and oily skin (seborrhea). This occurs because GH causes hypertrophy of the sweat (eccrine) and sebaceous glands. Hyperhidrosis is a sensitive clinical marker of disease activity; its resolution often indicates successful treatment. ### **Explanation of Incorrect Options** * **Visceromegaly (A):** GH/IGF-1 stimulate the growth of internal organs [3]. Common findings include cardiomegaly, hepatomegaly, splenomegaly, and thyroid enlargement [3]. * **Hypertension (C):** Approximately 30–50% of acromegalic patients have hypertension. It is caused by increased plasma volume (due to renal sodium retention) and increased peripheral vascular resistance. * **Soft tissue and bone enlargement (D):** This is the hallmark of the disease [3]. It manifests as increased glove/shoe size, "spade-like" hands, frontal bossing, and macroglossia [3]. ### **NEET-PG High-Yield Clinical Pearls** * **Screening Test:** Serum **IGF-1** levels (more stable than GH, which is pulsatile) [1]. * **Confirmatory Test:** **Oral Glucose Tolerance Test (OGTT)**; failure to suppress GH to <1 ng/mL after 75g glucose load is diagnostic [2]. * **Most Common Cause:** Somatotroph adenoma of the anterior pituitary [2]. * **Metabolic Associations:** Impaired glucose tolerance or Diabetes Mellitus (GH is a counter-regulatory hormone that causes insulin resistance). * **Mortality:** Most commonly due to **Cardiovascular disease** (congestive heart failure/arrhythmias). There is also an increased risk of **Colonic polyps/Carcinoma** [2].

Q: What is the most common association in Multiple Endocrine Neoplasia type 1 (MEN I)?

Gastrinoma. Multiple Endocrine Neoplasia type 1 (MEN 1), also known as **Wermer’s Syndrome**, is an autosomal dominant disorder caused by a mutation in the *MEN1* gene (encoding the protein Menin) [1]. It is classically characterized by the "3 Ps": **P**arathyroid (95%), **P**ancreatic Islet Cells (40-70%), and **P**ituitary (30-40%) [1]. **Why Gastrinoma is correct:** Among the pancreatic neuroendocrine tumors (NETs) associated with MEN 1, **Gastrinoma** is the most common functional tumor (occurring in ~40% of patients). It often leads to Zollinger-Ellison Syndrome, characterized by refractory peptic ulcers. While Parathyroid hyperplasia is the most common overall manifestation of MEN 1, among the options provided (which focus on pancreatic/associated tumors), Gastrinoma is the most frequent. **Analysis of Incorrect Options:** * **B. Insulinoma:** This is the second most common functional pancreatic NET in MEN 1, but it occurs less frequently than Gastrinoma (approx. 10-30%). * **C. Lipoma:** While cutaneous manifestations like lipomas, angiofibromas, and collagenomas are common in MEN 1, they are non-endocrine associations and occur less frequently or are less clinically diagnostic than Gastrinomas in the context of the syndrome's classic triad. * **D. Glucagonoma:** These are rare functional pancreatic tumors in MEN 1, occurring in less than 3% of cases. **NEET-PG High-Yield Pearls:** * **Most common initial presentation:** Hyperparathyroidism (Hypercalcemia). * **Most common Pituitary tumor:** Prolactinoma. * **Most common cause of death:** Malignant pancreatic NETs or Thymic carcinoids. * **Screening:** Genetic testing for *MEN1* gene mutations is the gold standard for family members [2].

Q: What is the most important initial step in the management of diabetic ketoacidosis?

Intravenous fluid resuscitation with isotonic saline. **Explanation:** The management of Diabetic Ketoacidosis (DKA) follows a prioritized sequence, where **Intravenous (IV) fluid resuscitation with isotonic saline (0.9% NaCl)** is the most critical initial step [1]. Patients with DKA typically have a massive fluid deficit (averaging 6–9 liters) due to osmotic diuresis [1]. Immediate hydration restores intravascular volume, improves renal perfusion (allowing for glucose excretion), and reduces the concentration of counter-regulatory hormones, which helps lower blood glucose levels even before insulin is started [2]. **Why other options are incorrect:** * **Insulin administration:** While essential to stop ketogenesis, insulin should only be started *after* fluid resuscitation has commenced and potassium levels are confirmed to be >3.3 mEq/L [2]. Starting insulin too early can cause an intracellular shift of water and potassium, potentially leading to vascular collapse or fatal arrhythmias [3]. * **Potassium repletion:** Although DKA involves a total body potassium deficit, repletion is secondary to ensuring adequate urine output via fluid resuscitation [3]. * **Sodium bicarbonate:** This is rarely indicated and only considered in extreme acidosis (pH < 6.9), as it can worsen intracellular acidosis and cause a rebound shift in the oxyhemoglobin dissociation curve. **High-Yield Clinical Pearls for NEET-PG:** * **The "Rule of 10":** Initial fluid bolus is typically 10-20 mL/kg in the first hour. * **Potassium Check:** Always check serum K+ before starting insulin [2]. If K+ < 3.3 mEq/L, hold insulin and replace potassium first. * **Switching Fluids:** Change from 0.9% NS to 5% Dextrose (D5) once blood glucose reaches ~200–250 mg/dL to prevent hypoglycemia while continuing the insulin infusion to clear ketones [2]. * **Resolution Marker:** DKA is considered resolved based on the **anion gap** and pH, not just the normalization of blood glucose [2].

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: Which of the following is true about Cushing's syndrome?

Proximal muscle weakness is present. **Explanation:** **Proximal muscle weakness (Option C)** is a hallmark clinical feature of Cushing’s syndrome, occurring in approximately 60–80% of patients. It is caused by the **catabolic effect of excess cortisol** on skeletal muscle, leading to the breakdown of muscle proteins (proteolysis) and subsequent atrophy of Type II fast-twitch muscle fibers [3]. This typically manifests as difficulty climbing stairs or rising from a seated position. **Analysis of Incorrect Options:** * **Option A:** While striae are characteristic, they are classically **purple/violaceous** and wide (>1 cm), not simply red. This color is due to the thinning of the dermis, making the underlying vascular subcutaneous tissue visible [3]. * **Option B:** Cushing’s syndrome involves the overproduction of **cortisol** (from the adrenal cortex), not adrenalin (from the adrenal medulla) [2]. * **Option C:** While cortisol has some mineralocorticoid activity that can cause fluid retention, **overt edema** is not a primary diagnostic feature of Cushing's unless there is severe ectopic ACTH production or co-existing heart/renal failure. **NEET-PG High-Yield Pearls:** * **Most common cause:** Overall, the most common cause is **exogenous steroid use**. The most common endogenous cause is **Cushing’s Disease** (ACTH-secreting pituitary adenoma) [2]. * **Screening Tests:** 24-hour urinary free cortisol, Low-dose dexamethasone suppression test (LDDST), or Late-night salivary cortisol [1], [4]. * **Hypokalemic Metabolic Alkalosis:** Often seen in ectopic ACTH syndrome (e.g., Small Cell Lung Cancer) due to massive cortisol levels saturating the 11β-HSD2 enzyme, leading to mineralocorticoid excess.

Q: A 63-year-old man recently treated for renal tuberculosis presents with weight loss, diarrhea, hypoglycemia, hypotension, and is noted to have hyperpigmented buccal mucosa, palmar and hand creases. Which investigation is most suitable for this clinical presentation?

Plasma ACTH and cortisol. **Explanation:** The clinical presentation of weight loss, diarrhea, hypoglycemia, and hypotension, combined with characteristic **hyperpigmentation** (buccal mucosa and palmar creases), is a classic description of **Primary Adrenal Insufficiency (Addison’s Disease)** [1]. In this patient, the history of **renal tuberculosis** is a critical clue, as TB remains a leading cause of adrenal destruction (Adrenal TB) [2]. 1. **Why Option C is correct:** The diagnosis of adrenal insufficiency is confirmed by demonstrating low cortisol levels. High **Plasma ACTH** levels (due to loss of negative feedback) confirm the site of pathology is the adrenal gland (Primary) rather than the pituitary (Secondary) [1]. Hyperpigmentation occurs because ACTH and Melanocyte-Stimulating Hormone (MSH) share a common precursor, Pro-opiomelanocortin (POMC). 2. **Why other options are incorrect:** * **Option A:** Iron studies are for Hemochromatosis. While it causes skin bronzing, it typically presents with diabetes ("bronze diabetes") and cirrhosis, not hypotension or hypoglycemia. * **Option B:** Copper studies are for Wilson’s disease, which presents with liver failure and neuropsychiatric symptoms, not adrenal crisis. * **Option D:** While GeneXpert is used to diagnose active TB, it does not assess organ function. IVP is an outdated imaging modality for renal anatomy and is not used to diagnose endocrine failure. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause worldwide:** Autoimmune adrenalitis. * **Most common cause in India:** Tuberculosis [2]. * **Electrolyte Triad:** Hyponatremia, Hyperkalemia, and Metabolic Acidosis. * **Gold Standard Test:** ACTH Stimulation Test (Cosyntropin test) [1]. * **Imaging:** In TB, CT may show enlarged, calcified adrenal glands [1].

Question 1

A 25-year-old man presents with a confused state, intense headache, profuse sweating, and eye rolling. His wife reports similar past events that resolved spontaneously. He smokes 20 packs of cigarettes per year and drinks 2-3 beers on weekends. On examination, he is confused, obeys simple commands, has intact deep tendon reflexes, and vital signs show BP 210/108 mm Hg and pulse 124/min. Laboratory results are: Na+ 142 meq/L, K+ 3.8 meq/L, BUN 30 mg/dL, S creatinine 1.0 mg/dL, and Blood sugar 110 mg/dL. What medication should be started preoperatively given the patient's condition?

Accepted Answer

Phenoxybenzamine and propranolol

Answer

Phentolamine and phenoxybenzamine

Answer

Propranolol

Answer

Nitroglycerine

Question 2

A 40-year-old man presents with central obesity, "buffalo hump," and violaceous purple striae on his abdomen. His fasting blood glucose levels are in the high normal range. Plasma levels of ACTH and cortisol are both increased compared to normal. An overnight high-dose dexamethasone suppression test produces 75% suppression of cortisol levels. What is the most likely diagnosis for this patient?

Accepted Answer

Cushing's disease

Answer

Addison's disease

Answer

An ectopic ACTH-secreting tumor

Answer

Conn's syndrome

Question 3

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 4

In Acromegaly, which of the following is NOT typically seen?

Accepted Answer

Decreased sweating

Answer

Visceromegaly

Answer

Hypertension

Answer

Soft tissue and bone enlargement

Question 5

What is the most common association in Multiple Endocrine Neoplasia type 1 (MEN I)?

Accepted Answer

Gastrinoma

Answer

Insulinoma

Answer

Lipoma

Answer

Glucagonoma

Question 6

What is the most important initial step in the management of diabetic ketoacidosis?

Accepted Answer

Intravenous fluid resuscitation with isotonic saline

Answer

Insulin administration

Answer

Administration of sodium bicarbonate

Answer

Potassium repletion

Question 7

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 8

Which of the following is true about Cushing's syndrome?

Accepted Answer

Proximal muscle weakness is present

Answer

Red striae are present

Answer

Increased adrenalin secretion

Answer

Edema is present

Question 9

Which of the following statements is true about SIADH?

Accepted Answer

Euvolemic Hyponatremia

Answer

Hypovolemic Hyponatremia

Answer

Hypervolemic Hyponatremia

Answer

Hypervolemic Hypernatremia

Question 10

A 63-year-old man recently treated for renal tuberculosis presents with weight loss, diarrhea, hypoglycemia, hypotension, and is noted to have hyperpigmented buccal mucosa, palmar and hand creases. Which investigation is most suitable for this clinical presentation?

Accepted Answer

Plasma ACTH and cortisol

Answer

Serum iron and ferritin

Answer

Serum copper and ceruloplasmin

Answer

Gene XPERT and Intravenous pyelography

Endocrinology — MCQs

Endocrinology — MCQs

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