Endocrinology — MCQs

Endocrinology Indian Medical PG Practice Questions and MCQs

Question 1211: Enlargement of a pituitary tumor after adrenalectomy is called as?

A. Nelson's syndrome (Correct Answer)
B. Steel-Richardson syndrome
C. Hamman-Rich syndrome
D. Job's syndrome

Explanation: **Explanation:** **Nelson’s Syndrome** (Option A) is the correct answer. It refers to the development of an ACTH-secreting pituitary adenoma following **bilateral adrenalectomy**, typically performed as a treatment for Cushing’s disease. [1] * **Mechanism:** The removal of both adrenal glands eliminates the negative feedback loop of cortisol on the hypothalamus and pituitary. In the absence of cortisol, the pre-existing pituitary microadenoma undergoes rapid growth and hypersecretion of ACTH and melanocyte-stimulating hormone (MSH). [1] * **Clinical Features:** Patients present with hyperpigmentation (due to high MSH levels) and symptoms of local tumor expansion, such as visual field defects and headaches. **Why other options are incorrect:** * **Steel-Richardson Syndrome (Option B):** Also known as Progressive Supranuclear Palsy (PSP), it is a neurodegenerative tauopathy characterized by vertical gaze palsy, postural instability, and falls. * **Hamman-Rich Syndrome (Option C):** Also known as Acute Interstitial Pneumonia (AIP), it is a rare, fulminant form of idiopathic diffuse lung disease leading to rapid respiratory failure. * **Job’s Syndrome (Option D):** Also known as Hyper-IgE Syndrome, it is a primary immunodeficiency characterized by the triad of high IgE levels, recurrent "cold" staphylococcal abscesses, and eczematoid dermatitis. **High-Yield Clinical Pearls for NEET-PG:** * **Diagnosis:** Elevated plasma ACTH levels (>200 pg/mL) and MRI evidence of an enlarging pituitary mass. * **Prevention:** The incidence of Nelson's syndrome has decreased significantly due to the use of transsphenoidal surgery (TSS) as the first-line treatment for Cushing’s disease, rather than bilateral adrenalectomy. * **Key Association:** Always look for the combination of **bilateral adrenalectomy + hyperpigmentation + pituitary mass** in clinical vignettes.

Question 1212: A patient with autoimmune thyroiditis presents with hypothyroidism. Which of the following is true?

A. Thyroid peroxidase antibodies (Correct Answer)
B. Painless enlargement of the thyroid
C. Common in men
D. No malignant risk

Explanation: **Explanation:** The patient presents with hypothyroidism secondary to **Hashimoto’s Thyroiditis** (Chronic Autoimmune Thyroiditis), which is the most common cause of hypothyroidism in iodine-sufficient regions. **1. Why Option A is Correct:** Hashimoto’s thyroiditis is characterized by the autoimmune destruction of the thyroid gland. **Thyroid Peroxidase (TPO) antibodies** are the hallmark of this condition, present in over 95% of patients. These antibodies mediate antibody-dependent cell-mediated cytotoxicity, leading to follicular destruction. While Antithyroglobulin (anti-Tg) antibodies are also found, TPO antibodies are more sensitive and better correlated with the progression to overt hypothyroidism [1]. **2. Why the other options are Incorrect:** * **Option B:** While the thyroid is often enlarged (goiter), it is typically **painless**, firm, and rubbery with a pyramidal lobe. Painful enlargement is characteristic of Subacute (De Quervain’s) Thyroiditis [1]. * **Option C:** Autoimmune thyroid diseases are significantly more common in **women** (female-to-male ratio of approximately 10:1 to 20:1). * **Option D:** There is a well-established increased risk of **Primary Thyroid Lymphoma** (specifically B-cell type) and a potential association with Papillary Thyroid Carcinoma in patients with long-standing Hashimoto’s. **High-Yield Clinical Pearls for NEET-PG:** * **Histology:** Look for **Hurthle cells** (Askanazy cells)—large eosinophilic granular follicular cells—and dense lymphocytic infiltrates with germinal centers. * **Initial Phase:** May present with transient hyperthyroidism ("Hashitoxicosis") due to the release of preformed hormones [1]. * **HLA Association:** Strongly associated with **HLA-DR5** and HLA-DR3. * **Treatment:** Levothyroxine (T4) is the mainstay of therapy; the goal is to normalize TSH levels [1]. **Note on Thyroiditis:** In the thyrotoxic phase of various thyroiditides, iodine uptake is low because damaged cells cannot trap iodine [1].

Question 1213: A 26-year-old woman has episodic hypertension with headache, diaphoresis, and palpitation. Which of the following diagnostic procedures would be most useful in evaluating the possibility that pheochromocytoma might be the cause of these findings?

A. Serum C-peptide
B. Serum calcitonin
C. Urinary vanillylmandelic acid (Correct Answer)
D. Urinary aldosterone

Explanation: ### Explanation **Correct Option: C. Urinary vanillylmandelic acid (VMA)** The clinical triad of **episodic hypertension, headache, diaphoresis, and palpitations** is classic for **Pheochromocytoma**, a catecholamine-secreting tumor of the adrenal medulla. **Why it is correct:** Catecholamines (epinephrine and norepinephrine) are metabolized into metanephrines and normetanephrines, which are further broken down into **Vanillylmandelic Acid (VMA)**. Measuring 24-hour urinary VMA or metanephrines is a standard biochemical screening tool to confirm excess catecholamine production. While plasma-free metanephrines are more sensitive, 24-hour urinary VMA remains a high-yield diagnostic marker in exams for confirming the diagnosis. **Why other options are incorrect:** * **A. Serum C-peptide:** This is a byproduct of endogenous insulin production. It is used to evaluate hypoglycemia (e.g., Insulinoma) or to distinguish Type 1 from Type 2 Diabetes, but it has no role in blood pressure regulation. * **B. Serum calcitonin:** This is a tumor marker for **Medullary Thyroid Carcinoma (MTC)**. While MTC is associated with Pheochromocytoma in MEN 2A and 2B syndromes, calcitonin itself does not cause hypertension or palpitations. * **D. Urinary aldosterone:** This is used to diagnose **Primary Hyperaldosteronism (Conn’s Syndrome)**. While it causes hypertension, it typically presents with hypokalemia and lacks the "episodic" paroxysmal symptoms (headache/sweating) seen in pheochromocytoma [1]. --- ### NEET-PG High-Yield Pearls * **Rule of 10s:** 10% are bilateral, 10% are extra-adrenal (Paragangliomas), 10% are malignant, and 10% occur in children. * **Best Initial Screening Test:** Plasma-free metanephrines (highest sensitivity). * **Most Specific Test:** 24-hour urinary metanephrines and VMA. * **Pre-operative Management:** Always give **Alpha-blockers first** (e.g., Phenoxybenzamine) followed by Beta-blockers to avoid a hypertensive crisis (unopposed alpha-stimulation) [1]. * **Associated Syndromes:** MEN 2A, MEN 2B, von Hippel-Lindau (VHL), and NF-1 [1].

Question 1214: A patient has random plasma glucose levels of 110 mg/dL and 113 mg/dL on two separate occasions. What advice would you give?

A. Declare him as having Diabetes mellitus.
B. Proceed for an oral glucose tolerance test.
C. Declare the patient as normal. (Correct Answer)
D. Check for glycosylated hemoglobin and if it is raised, declare him as having DM.

Explanation: To answer this question correctly, one must strictly adhere to the diagnostic criteria for Diabetes Mellitus (DM) as defined by the ADA and WHO [1]. ### **Explanation of the Correct Answer** The patient’s random plasma glucose (RPG) levels are **110 mg/dL and 113 mg/dL**. According to standard guidelines, a diagnosis of Diabetes Mellitus based on a random sample requires a glucose level of **≥200 mg/dL** accompanied by classic symptoms of hyperglycemia (polyuria, polydipsia, weight loss) [1]. Since these values are well below the 200 mg/dL threshold and fall within a range that would be considered normal even for fasting states (normal fasting is <100 mg/dL; normal post-prandial is <140 mg/dL), the patient is clinically **normal**. There is no indication of hyperglycemia. ### **Analysis of Incorrect Options** * **Option A:** To declare DM, the RPG must be ≥200 mg/dL with symptoms, or Fasting Plasma Glucose (FPG) must be ≥126 mg/dL [1]. 113 mg/dL does not meet any criteria. * **Option B:** An Oral Glucose Tolerance Test (OGTT) is indicated if the FPG is in the "Prediabetes" range (100–125 mg/dL) to further investigate. These random values do not justify the cost or time of an OGTT. * **Option D:** HbA1c is used for diagnosis if it is ≥6.5%. However, checking it is unnecessary here because the random glucose levels are completely normal. ### **High-Yield Clinical Pearls for NEET-PG** * **Diagnostic Thresholds for DM:** * **HbA1c:** ≥ 6.5% * **Fasting Plasma Glucose (FPG):** ≥ 126 mg/dL (7.0 mmol/L) [1] * **2-hour OGTT (75g load):** ≥ 200 mg/dL (11.1 mmol/L) * **Random Plasma Glucose:** ≥ 200 mg/dL + Symptoms [1]. * **Prediabetes (Impaired Fasting Glucose):** FPG between 100–125 mg/dL. * **Prediabetes (Impaired Glucose Tolerance):** 2-hour OGTT between 140–199 mg/dL. * **Note:** Unless clear symptoms are present, a diagnosis of DM requires **two** abnormal test results from the same sample or two separate test samples.

Question 1215: Which of the following is NOT TRUE regarding Hashimoto's thyroiditis?

A. Neutrophilic infiltration
B. Maximum incidence in children
C. Pain in the hyoid region
D. None of the above (Correct Answer)

Explanation: **Explanation:** Hashimoto’s Thyroiditis (Chronic Lymphocytic Thyroiditis) is the most common cause of hypothyroidism in iodine-sufficient regions. It is an autoimmune condition characterized by the destruction of thyroid follicles. **Analysis of Options:** * **Option A (Neutrophilic infiltration):** This is **NOT** a feature of Hashimoto’s. The hallmark histopathology shows a dense **lymphocytic and plasma cell infiltrate** with the formation of germinal centers. Neutrophilic infiltration is typically seen in acute infectious (suppurative) thyroiditis. * **Option B (Maximum incidence in children):** This is **NOT** true. Hashimoto’s thyroiditis most commonly affects **middle-aged women** (between 30 and 50 years of age), with a female-to-male ratio of approximately 10:1 to 20:1. * **Option C (Pain in the hyoid region):** This is **NOT** true. Hashimoto’s is typically a **painless**, diffuse enlargement of the thyroid (goiter). Pain and tenderness are characteristic features of Subacute Granulomatous (De Quervain’s) Thyroiditis or infectious thyroiditis. Since **all three statements (A, B, and C) are incorrect** regarding Hashimoto’s thyroiditis, the question asks which is "NOT TRUE." Technically, all are false. In the context of this specific MCQ structure, "None of the above" is the designated correct answer because none of the provided statements accurately describe the disease. **NEET-PG High-Yield Pearls:** * **Histology:** Look for **Hürthle cells** (Askanazy cells)—large epithelial cells with abundant eosinophilic, granular cytoplasm. * **Antibodies:** High titers of **Anti-TPO** (Antithyroid peroxidase) and **Anti-Tg** (Antithyroglobulin) antibodies. * **Risk:** Increased risk of **B-cell Non-Hodgkin Lymphoma** of the thyroid and other autoimmune diseases (e.g., Type 1 Diabetes, Pernicious Anemia). * **Genetics:** Associated with **HLA-DR3 and HLA-DR5**.

Question 1216: The triad of cirrhosis, hemochromatosis, and diabetes is referred to as which of the following?

A. Silver diabetes
B. Diabetes mellitus
C. Diabetes insipidus
D. Bronze diabetes (Correct Answer)

Explanation: **Explanation:** The correct answer is **Bronze diabetes**. This term refers to the classic clinical triad seen in **Hereditary Hemochromatosis**, an autosomal recessive disorder characterized by excessive intestinal iron absorption and subsequent deposition in various organs [1]. 1. **Why it is correct:** In Hemochromatosis, iron (hemosiderin) deposits in the **pancreas**, leading to islet cell destruction and secondary diabetes mellitus [1]. Simultaneously, iron deposition in the **liver** causes cirrhosis, and deposition in the **skin** (along with increased melanin production) results in a characteristic metallic, slate-gray, or "bronze" hyperpigmentation [1]. The combination of these three features—Cirrhosis, Diabetes, and Hyperpigmentation—defines "Bronze Diabetes." 2. **Why the other options are incorrect:** * **Silver diabetes:** This is not a recognized medical term for any specific clinical syndrome. * **Diabetes mellitus:** While this is a component of the triad, it refers generally to hyperglycemia and does not encompass the multisystem involvement of iron overload. * **Diabetes insipidus:** This is a disorder of water metabolism caused by a deficiency of or resistance to Antidiuretic Hormone (ADH), unrelated to iron overload or cirrhosis. **High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** Most commonly due to a mutation in the **HFE gene** (C282Y mutation on Chromosome 6) [1][2]. * **Screening:** The most sensitive initial test is **Transferrin Saturation** (>45% is suggestive). * **Gold Standard Diagnosis:** Liver biopsy (Perls' Prussian Blue stain) or MRI (T2* weighted) to quantify iron overload [2]. * **Other Features:** "Honeymooner’s Arthritis" (2nd/3rd MCP joints), Dilated Cardiomyopathy, and Hypogonadotropic Hypogonadism [1]. * **Treatment:** Therapeutic phlebotomy is the mainstay of management [2].

Question 1217: Which of the following investigations is used to differentiate between hypercalcemia of malignancy and primary hyperparathyroidism?

A. Hydrocortisone suppression test (Correct Answer)
B. Glucose challenge test
C. 24-hour urine calcium measurement
D. Percentage of ionized calcium

Explanation: The **Hydrocortisone suppression test** (also known as the Dent test) is a classic biochemical tool used to differentiate causes of hypercalcemia. **1. Why Option A is Correct:** In **Hypercalcemia of Malignancy** (specifically those involving bone metastases, multiple myeloma, or sarcoidosis), the administration of high-dose glucocorticoids (e.g., 100 mg hydrocortisone daily for 10 days) typically **lowers** serum calcium levels [1]. Glucocorticoids reduce calcium by inhibiting Vitamin D-mediated intestinal absorption and suppressing cytokine-induced osteoclast activity. In contrast, in **Primary Hyperparathyroidism (PHPT)**, the hypercalcemia is driven by autonomous PTH secretion, which is **not suppressed** by steroids. Therefore, a failure of calcium levels to drop suggests PHPT [1]. **2. Why the Other Options are Incorrect:** * **B. Glucose challenge test:** This is used to diagnose Acromegaly (failure of Growth Hormone suppression) and has no role in calcium metabolism. * **C. 24-hour urine calcium:** This is primarily used to differentiate PHPT from **Familial Hypocalciuric Hypercalcemia (FHH)** [1]. In FHH, urine calcium is low (Calcium:Creatinine clearance ratio <0.01), whereas it is normal or high in PHPT [1]. * **D. Percentage of ionized calcium:** While ionized calcium is the physiologically active form, it does not reliably differentiate the underlying etiology of hypercalcemia, as it can be elevated in both malignancy and PHPT [1]. **Clinical Pearls for NEET-PG:** * **Most common cause of hypercalcemia in outpatients:** Primary Hyperparathyroidism. * **Most common cause of hypercalcemia in hospitalized patients:** Malignancy [1]. * **PTH levels:** In PHPT, PTH is elevated or inappropriately normal. In malignancy-associated hypercalcemia, PTH is typically suppressed (low) [1]. * **PTHrP:** This is the mediator in Humoral Hypercalcemia of Malignancy (e.g., Squamous cell carcinoma of the lung).

Question 1218: Diabetes mellitus is associated with all of the following conditions except?

A. Pendred syndrome (Correct Answer)
B. Down's syndrome
C. Turner's syndrome
D. Klinefelter's syndrome

Explanation: **Explanation** The correct answer is **Pendred syndrome**. **1. Why Pendred syndrome is the correct answer:** Pendred syndrome is an autosomal recessive disorder caused by mutations in the *SLC26A4* gene (encoding the pendrin protein). It is classically characterized by a triad of **sensorineural hearing loss**, **goiter**, and an abnormal perchlorate discharge test. While it involves the thyroid gland (hypothyroidism or euthyroid goiter), it has **no established clinical association with Diabetes Mellitus** [1]. **2. Why the other options are incorrect:** Chromosomal aneuploidies are frequently associated with an increased risk of autoimmune and metabolic endocrine disorders, including Diabetes Mellitus: * **Down’s syndrome (Trisomy 21):** Patients have a significantly higher prevalence of **Type 1 Diabetes Mellitus** due to increased susceptibility to autoimmunity [2]. * **Turner’s syndrome (45, XO):** There is a high incidence of **Type 2 Diabetes** and impaired glucose tolerance, likely due to a combination of haploinsufficiency of X-chromosome genes affecting insulin sensitivity and beta-cell function [3]. * **Klinefelter’s syndrome (47, XXY):** These patients often exhibit abdominal obesity and hypogonadism, leading to insulin resistance and a high risk of **Type 2 Diabetes** and Metabolic Syndrome. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic for Pendred Syndrome:** "P" for **P**endred, **P**erchlorate test, and **P**erceptive (sensorineural) deafness. * **Other Genetic Syndromes associated with DM:** Wolfram syndrome (DIDMOAD), Prader-Willi syndrome, Alström syndrome, and Friedreich’s ataxia. * **Wolfram Syndrome (DIDMOAD):** **D**iabetes **I**nsipidus, **D**iabetes **M**ellitus, **O**ptic **A**trophy, and **D**eafness.

Question 1219: Wermer syndrome is characterized by which of the following?

A. Multiple Endocrine Neoplasia type 1 (MEN 1) (Correct Answer)
B. Multiple Endocrine Neoplasia type 2A (MEN 2A)
C. Multiple Endocrine Neoplasia type 2B (MEN 2B)
D. Acute Intermittent Porphyria (AIP)

Explanation: **Explanation:** **Wermer Syndrome** is the eponym for **Multiple Endocrine Neoplasia type 1 (MEN 1)**. It is an autosomal dominant disorder caused by a mutation in the *MEN1* gene on chromosome 11q13, which encodes the protein **menin**, a tumor suppressor. The syndrome is classically characterized by the **"3 Ps"**: 1. **Parathyroid hyperplasia:** The most common feature (present in >95% of cases), leading to primary hyperparathyroidism. 2. **Pancreatic islet cell tumors:** Most commonly Gastrinomas (Zollinger-Ellison Syndrome) or Insulinomas. 3. **Pituitary adenomas:** Most commonly Prolactinomas. **Analysis of Incorrect Options:** * **MEN 2A (Sipple Syndrome):** Characterized by Medullary Thyroid Carcinoma (MTC), Pheochromocytoma, and Parathyroid hyperplasia. It is associated with the *RET* proto-oncogene. * **MEN 2B (Wagenmann-Froboese Syndrome):** Characterized by MTC, Pheochromocytoma, Mucosal neuromas, and Marfanoid habitus. It does *not* typically involve the parathyroid glands. * **Acute Intermittent Porphyria (AIP):** A metabolic disorder of heme biosynthesis; it is unrelated to the MEN syndromes. **High-Yield Clinical Pearls for NEET-PG:** * **Most common initial presentation of MEN 1:** Hypercalcemia (due to hyperparathyroidism). * **Most common pituitary tumor in MEN 1:** Prolactinoma. * **Most common cause of death in MEN 1:** Malignant pancreatic neuroendocrine tumors (especially Gastrinomas). * **Screening:** Genetic testing for *MEN1* mutation is recommended for first-degree relatives of affected patients.

Question 1220: Gallstones are associated with which neuroendocrine tumor?

A. Insulinoma
B. VIPoma
C. Somatostatinoma (Correct Answer)
D. Glucagonoma

Explanation: The correct answer is **Somatostatinoma**. **1. Why Somatostatinoma is correct:** Somatostatinomas are rare neuroendocrine tumors (NETs) that secrete excessive amounts of **somatostatin** [1]. Somatostatin is a potent inhibitory hormone. In the biliary system, it inhibits the release of **Cholecystokinin (CCK)** and directly suppresses gallbladder contractility. This leads to profound **biliary stasis**, resulting in the formation of gallstones (cholelithiasis). The classic "Somatostatinoma Syndrome" triad consists of: * **Diabetes Mellitus** (due to inhibition of insulin/glucagon) * **Cholelithiasis** (due to biliary stasis) * **Steatorrhea** (due to inhibition of pancreatic enzymes and bicarbonate) **2. Why the other options are incorrect:** * **Insulinoma:** Presents with Whipple’s triad (hypoglycemia symptoms, low plasma glucose, and relief upon glucose administration). It is not associated with gallstones. * **VIPoma:** Characterized by **WDHA Syndrome** (Watery Diarrhea, Hypokalemia, and Achlorhydria). It causes massive secretory diarrhea but does not directly cause gallstones. * **Glucagonoma:** Presents with the "4Ds": **D**ermatitis (Necrolytic Migratory Erythema), **D**iabetes, **D**eep vein thrombosis, and **D**epression. **3. High-Yield Clinical Pearls for NEET-PG:** * **Most common location:** Somatostatinomas are most frequently found in the **pancreas** (head) or the **duodenum**. * **Psammoma bodies:** Duodenal somatostatinomas are uniquely associated with the presence of psammoma bodies on histology. * **Association:** Often associated with **MEN-1** and **Neurofibromatosis type 1 (NF-1)**. * **Octreotide Link:** Long-term therapeutic use of Octreotide (a somatostatin analogue) also carries a high risk of gallstone formation for the same physiological reasons.

Practice by Chapter

Diabetes Mellitus

Practice Questions

Thyroid Disorders

Practice Questions

Adrenal Gland Disorders

Practice Questions

Pituitary Disorders

Practice Questions

Calcium and Bone Metabolism

Practice Questions

Reproductive Endocrinology

Practice Questions

Lipid Disorders

Practice Questions

Endocrine Hypertension

Practice Questions

Multiple Endocrine Neoplasia

Practice Questions

Obesity and Metabolic Syndrome

Practice Questions

Neuroendocrine Tumors

Practice Questions

Endocrine Emergencies

Practice Questions

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