Endocrinology Practice Questions

Q: Which of the following statements regarding Wolfram syndrome is FALSE?

Retrobulbar neuritis. Wolfram syndrome is a rare autosomal recessive neurodegenerative disorder caused by mutations in the **WFS1 gene** (encoding the protein Wolframin). It is classically defined by the mnemonic **DIDMOAD**, which helps identify its core clinical features. ### Why "Retrobulbar Neuritis" is the Correct Answer (False Statement) Wolfram syndrome is characterized by **Optic Atrophy**, which is a progressive, irreversible degeneration of the optic nerve leading to loss of visual acuity and color vision. In contrast, **Retrobulbar neuritis** is an acute inflammatory process (often associated with Multiple Sclerosis) that presents with sudden vision loss and pain on eye movement. While both affect the optic nerve, the underlying pathology in Wolfram syndrome is genetic neurodegeneration, not primary inflammation. ### Analysis of Incorrect Options (True Statements) * **A. Diabetes Mellitus:** This is typically the first manifestation, usually presenting in the first decade of life. Unlike Type 1 DM, it is non-autoimmune. * **B. Optic Atrophy:** A hallmark feature (the "OA" in DIDMOAD), usually occurring by age 11. It leads to bilateral blindness [1]. * **D. Sensorineural Deafness:** Present in approximately 65% of patients (the "D" in DIDMOAD), it typically affects high-frequency sounds [1]. ### High-Yield Clinical Pearls for NEET-PG * **DIDMOAD Mnemonic:** **D**iabetes **I**nsipidus, **D**iabetes **M**ellitus, **O**ptic **A**trophy, and **D**eafness. * **Diabetes Insipidus:** Specifically **Central Diabetes Insipidus**, occurring in about 70% of cases. * **Urological Findings:** Patients often develop a neurogenic bladder and hydroureter. * **Inheritance:** Autosomal Recessive (Chromosome 4p). * **Prognosis:** It is a progressive disease; the median age of death is usually in the 30s, often due to respiratory failure caused by brainstem atrophy.

Q: What is used for long-term glycemic control in Diabetes Mellitus?

Glycated hemoglobin. ### Explanation **Correct Answer: B. Glycated hemoglobin (HbA1c)** **Why it is correct:** Glycated hemoglobin (HbA1c) is formed when glucose binds non-enzymatically to the hemoglobin molecule within red blood cells (RBCs) [2]. Because RBCs have an average lifespan of approximately **120 days**, the HbA1c level reflects the average blood glucose concentration over the preceding **2–3 months** [3]. This makes it the "gold standard" for monitoring long-term glycemic control and assessing the risk of chronic diabetic complications [4]. **Why the other options are incorrect:** * **A. Total protein:** While albumin can be glycated (forming Fructosamine), total protein is not a specific or standard measure for glycemic monitoring. * **C. Total hemoglobin:** This measures the oxygen-carrying capacity of the blood and is used to diagnose anemia, not to monitor glucose levels [2]. * **D. Glucose tolerance test (GTT):** This is a diagnostic tool used to identify Gestational Diabetes or Impaired Glucose Tolerance. It reflects glucose handling at a single point in time, not long-term control [1]. **High-Yield Clinical Pearls for NEET-PG:** * **The 1% Rule:** For every 1% change in HbA1c, the mean plasma glucose changes by approximately **30–35 mg/dL** [4]. * **Fructosamine Test:** Reflects glycemic control over the past **2–3 weeks**. It is useful in patients with hemoglobinopathies (e.g., Thalassemia, Sickle Cell) where HbA1c may be unreliable. * **False Low HbA1c:** Seen in conditions with decreased RBC lifespan (e.g., Hemolytic anemia, acute blood loss, or treatment with Erythropoietin). * **False High HbA1c:** Seen in conditions with increased RBC lifespan or altered glycation (e.g., Iron deficiency anemia, Vitamin B12 deficiency).

Q: Hypothyroidism is seen in which of the following conditions?

Hashimoto's thyroiditis. **Explanation:** **Hashimoto’s Thyroiditis (Correct Answer):** Hashimoto’s thyroiditis (Chronic Autoimmune Thyroiditis) is the most common cause of hypothyroidism in iodine-sufficient regions. It is characterized by the autoimmune destruction of the thyroid gland mediated by T-cell-induced apoptosis and the presence of anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-Tg) antibodies. Histologically, it shows diffuse lymphocytic infiltration and the presence of **Hürthle cells** (Askanazy cells). **Why the other options are incorrect:** * **Graves’ Disease:** This is an autoimmune condition caused by Thyroid Stimulating Immunoglobulins (TSI) that bind to and activate the TSH receptor, leading to **hyperthyroidism**, not hypothyroidism [1]. * **Toxic Multinodular Goiter (Plummer Disease):** This involves autonomous hyperfunctioning nodules that secrete excess thyroid hormones (T3/T4) independent of TSH, resulting in **hyperthyroidism**. * **Struma Ovarii:** This is a rare specialized ovarian teratoma composed predominantly of thyroid tissue. If this ectopic tissue becomes overactive, it leads to **hyperthyroidism** (ectopic thyrotoxicosis) with low iodine uptake in the neck. **NEET-PG High-Yield Pearls:** * **Most common cause of goitrous hypothyroidism:** Hashimoto’s thyroiditis. * **Most common cause of hypothyroidism worldwide:** Iodine deficiency. * **Marker of choice:** Anti-TPO antibodies are present in >90% of Hashimoto’s patients. * **Associated Risk:** Patients with Hashimoto’s have an increased risk of developing **B-cell Non-Hodgkin Lymphoma** of the thyroid. * **Wolff-Chaikoff Effect:** A transient reduction in thyroid hormone levels following ingestion of a large amount of iodine, often seen in Hashimoto's patients.

Q: Tetany may be a feature of the following conditions except?

Hyponatremia. **Explanation:** Tetany is a state of increased neuromuscular excitability characterized by carpopedal spasms, paresthesia, and laryngospasm. It is primarily driven by a decrease in the concentration of **ionized calcium ($Ca^{2+}$)** in the extracellular fluid. **Why Hyponatremia is the Correct Answer:** Hyponatremia (low serum sodium) does not cause tetany. In fact, severe hyponatremia typically leads to CNS symptoms like cerebral edema, seizures, and coma, but it does not increase neuromuscular irritability in the peripheral nerves. Therefore, it is the "except" in this list. **Analysis of Other Options:** * **Hyperventilation:** This leads to respiratory alkalosis. Alkalosis promotes the binding of ionized calcium to albumin, reducing the physiologically active $Ca^{2+}$ fraction, thereby triggering tetany. * **Hypokalemic Alkalosis:** Metabolic alkalosis (often seen in Conn’s syndrome or vomiting) similarly reduces ionized calcium levels [1]. While hypokalemia itself usually causes muscle weakness, the concomitant **alkalosis** is a classic trigger for tetany [1]. * **Hypomagnesemia:** Magnesium is a co-factor for adenylate cyclase; its deficiency leads to impaired PTH secretion and end-organ resistance to PTH, resulting in secondary hypocalcemia and tetany. **NEET-PG High-Yield Pearls:** 1. **Trousseau’s Sign:** Induction of carpal spasm by inflating a BP cuff above systolic pressure for 3 minutes (more sensitive than Chvostek’s). 2. **Chvostek’s Sign:** Tapping the facial nerve leads to twitching of facial muscles. 3. **The Ionized Calcium Rule:** Total calcium may be normal in alkalosis, but tetany occurs because the **ionized (free) fraction** decreases. 4. **Refractory Hypocalcemia:** If hypocalcemia does not respond to calcium gluconate, always check and correct **Magnesium** levels first.

Q: If both parents have type 2 diabetes, what is the approximate risk of inheritance for their offspring?

40%. Type 2 Diabetes Mellitus (T2DM) has a much stronger genetic component than Type 1 Diabetes. The inheritance pattern is polygenic and multifactorial, meaning multiple genes interact with environmental factors (obesity, sedentary lifestyle). [1] **Why 40% is correct:** Epidemiological studies and twin studies have established specific risk profiles for offspring based on parental history: * **One parent affected:** The risk of developing T2DM is approximately **40%**. * **Both parents affected:** The risk increases significantly, approaching **70%**. *Note on the Question:* In many standard medical textbooks (like Harrison’s Principles of Internal Medicine), the lifetime risk for an offspring with **one** affected parent is cited as 40%. However, in the context of competitive exams like NEET-PG, if 40% is marked as the correct answer for

Q: A 40-year-old patient presents with episodic hypertension, severe headache, diaphoresis, and palpitations. The CT scan of the abdomen is shown in the image. What is the most likely diagnosis?

Pheochromocytoma. ***Pheochromocytoma*** - The classic triad of **episodic hypertension**, **severe headache**, **diaphoresis**, and **palpitations** strongly suggests **catecholamine excess** from a pheochromocytoma. - CT imaging typically shows an **adrenal mass** with **heterogeneous enhancement** and possible **central necrosis**, confirmed by elevated **24-hour urine metanephrines** or **plasma metanephrines**. *Coarctation of the aorta* - Presents with **continuous hypertension** and **blood pressure differential** between upper and lower extremities, not episodic symptoms. - Associated with **rib notching** on chest X-ray and **weak femoral pulses**, which are absent in this case. *Primary hyperaldosteronism* - Causes **sustained hypertension** with **hypokalemia** and **metabolic alkalosis**, not episodic catecholamine symptoms. - Presents with **muscle weakness** and **polyuria** due to **aldosterone excess**, lacking the classic triad described. *Renal artery stenosis* - Results in **renovascular hypertension** with **renal bruit** and possible **flash pulmonary edema**, not episodic symptoms. - Associated with **atherosclerotic disease** or **fibromuscular dysplasia**, typically showing **kidney size asymmetry** on imaging.

Q: Hypoglycemia is associated with all of the following conditions, EXCEPT:

Small cell carcinoma of the lung. ### Explanation The correct answer is **Small Cell Carcinoma (SCC) of the lung**. **1. Why Small Cell Carcinoma is the correct answer:** Small cell carcinoma of the lung is a neuroendocrine tumor famously associated with various paraneoplastic syndromes, most notably **SIADH** (excessive ADH) and **Cushing’s Syndrome** (ectopic ACTH) [1]. However, it is **not** typically associated with hypoglycemia. In contrast, hypoglycemia in malignancy is usually mediated by the secretion of **"Big-IGF-II"** (incomplete insulin-like growth factor II), a phenomenon known as **Doege-Potter Syndrome**. **2. Analysis of Incorrect Options (Conditions associated with hypoglycemia):** * **Fibroma & Soft Tissue Sarcoma (Options A & B):** These are mesenchymal tumors. Large mesenchymal tumors (like solitary fibrous tumors or hemangiopericytomas) are the most common cause of **Non-Islet Cell Tumor Hypoglycemia (NICTH)**. They secrete "Big-IGF-II," which binds to insulin receptors and increases glucose utilization while inhibiting hepatic glucose production. * **Hepatocellular Carcinoma (Option D):** HCC can cause hypoglycemia via two mechanisms: rapidly growing tumors may outpace the liver's glycogen stores/gluconeogenic capacity (Type B), or the tumor may secrete IGF-II (Type A) [1]. **3. NEET-PG Clinical Pearls:** * **Doege-Potter Syndrome:** Hypoglycemia specifically associated with solitary fibrous tumors (mesenchymal). * **NICTH vs. Insulinoma:** In NICTH, both **Insulin and C-peptide levels are suppressed**, whereas, in Insulinoma, both are elevated [2]. * **IGF-II Mechanism:** "Big-IGF-II" is the hallmark of paraneoplastic hypoglycemia in non-islet cell tumors. * **SCC Lung Associations:** Remember the "3 S's": **S**IADH, **S**ubacute cerebellar degeneration, and ACTH (**S**teroids/Cushing's). It also causes Lambert-Eaton Syndrome [1].

Question 1

A smoker presented with altered sensorium. His blood osmolality was found to be 240 mOsm/kg, urine osmolality 340 mOsm/kg, and serum Na+ is 122 mEq/L. What is the most likely diagnosis?

Accepted Answer

Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH)

Answer

Diabetes insipidus

Answer

Renal tubular acidosis

Answer

Cerebellar degeneration

Question 2

Which vaccine can be given to an individual with chronic diabetes mellitus?

Accepted Answer

Meningococcal and pneumococcal vaccines at recommended intervals, and influenza vaccine annually.

Answer

Meningococcal and tetanus vaccines at recommended intervals, and hepatitis B vaccine annually.

Answer

Tetanus and pneumococcal vaccines at recommended intervals, and influenza vaccine annually.

Answer

Meningococcal and pneumococcal vaccines at recommended intervals, and hepatitis vaccine annually.

Question 3

Which of the following statements regarding Wolfram syndrome is FALSE?

Accepted Answer

Retrobulbar neuritis

Answer

Diabetes mellitus

Answer

Optic atrophy

Answer

Sensorineural deafness

Question 4

What is used for long-term glycemic control in Diabetes Mellitus?

Accepted Answer

Glycated hemoglobin

Answer

Total protein

Answer

Total hemoglobin

Answer

Glucose tolerance test

Question 5

Hypothyroidism is seen in which of the following conditions?

Accepted Answer

Hashimoto's thyroiditis

Answer

Graves disease

Answer

Toxic multinodular goiter

Answer

Struma ovarii

Question 6

Tetany may be a feature of the following conditions except?

Accepted Answer

Hyponatremia

Answer

Hyperventilation

Answer

Hypokalemic alkalosis

Answer

Hypomagnesemia

Question 7

If both parents have type 2 diabetes, what is the approximate risk of inheritance for their offspring?

Accepted Answer

40%

Answer

10%

Answer

20%

Answer

30%

Question 8

A 33-year-old woman presents with gradually increasing coarse hair on her upper lip, chin, and lower abdomen for the past 3 years. She has mild facial acne but denies frontal balding or deepening of voice. Her menses are irregular, occurring every 28 to 60 days. Her BMI is 29.0 and her waist circumference is 36 inches. There is mild acanthosis nigricans of the axillae. Pelvic examination is normal without ovarian mass or clitoromegaly. What evaluation is indicated for her hirsutism?

Accepted Answer

Serum testosterone and dehydroepiandrosterone-sulfate (DHEA-S) level

Answer

Glucose tolerance test

Answer

Overnight dexamethasone suppression test with 8 am cortisol level

Answer

CT scan of adrenals

Question 9

A 40-year-old patient presents with episodic hypertension, severe headache, diaphoresis, and palpitations. The CT scan of the abdomen is shown in the image. What is the most likely diagnosis?

Accepted Answer

Pheochromocytoma

Answer

Coarctation of the aorta

Answer

Primary hyperaldosteronism

Answer

Renal artery stenosis

Question 10

Hypoglycemia is associated with all of the following conditions, EXCEPT:

Accepted Answer

Small cell carcinoma of the lung

Answer

Fibroma

Answer

Soft tissue sarcoma

Answer

Hepatocellular carcinoma

Endocrinology — MCQs

Endocrinology — MCQs

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