Endocrinology — MCQs

A 50-year-old woman, who is 5 feet 7 inches tall and weighs 185 pounds, has a family history of diabetes mellitus. Her fasting blood glucose levels are 160 mg/dL and 155 mg/dL on two occasions, and her HbA1c level is 7.9%. After being educated on medical nutrition therapy, she returns for reevaluation in 8 weeks, reporting that she has followed diet and exercise recommendations, but her fasting blood glucose levels remain between 140 and 150 mg/dL, and her HbA1c level is 7.7%. She is asymptomatic, and physical examination reveals no abnormalities. Which of the following treatments is the most appropriate for her condition?

Q1608

A patient presents with symptoms of hyperthyroidism. Thyroid function tests would probably reveal:

Q1609

A 30-year-old male presents with erectile dysfunction, low testosterone, and elevated prolactin levels. What is the most likely diagnosis?

Q1610

What is the most common adrenal incidentaloma?

Endocrinology Indian Medical PG Practice Questions and MCQs

Question 1601: What is a significant cause of male pseudohermaphroditism?

A. Adrenocortical tumor
B. Cytogenetic abnormalities
C. Androgen insensitivity syndrome (Correct Answer)
D. Congenital adrenal hyperplasia (CAH)

Explanation: ***Cytogenetic abnormalities*** - Male pseudohermaphroditism is most commonly caused by **isolated androgen insensitivity syndrome**, resulting from **androgen receptor gene mutations** [3]. - It leads to **male chromosomal composition (46,XY)** but with female phenotype due to lack of response to male hormones [3]. *Chromosomal abnormalities* - While chromosomal abnormalities can lead to **disorders of sexual development**, they are not the primary cause of pseudohermaphroditism [2], [3]. - Conditions like **Turner syndrome** affect development primarily in female individuals [1]. *Congenital adrenal hyperplasia* - More commonly leads to **female pseudohermaphroditism** due to excess androgen exposure during fetal life [3]. - In male infants, it typically presents as **salt-wasting**, affecting the adrenal glands rather than causing male pseudohermaphroditism [3]. *Adrenocortical tumor* - This condition can cause excess secretion of adrenal hormones, potentially leading to **precocious puberty**, but it does not typically cause pseudohermaphroditism. - It primarily affects adrenal function rather than sexual differentiation at the chromosomal level.

Question 1602: Madarosis is seen in ?

A. None of the options
B. Addison's disease
C. Acromegaly
D. Hypothyroidism (Correct Answer)

Explanation: ***Hypothyroidism*** - **Madarosis**, specifically the loss of the **outer third of the eyebrows**, is a classic sign of **hypothyroidism** due to decreased thyroid hormone levels affecting hair follicle growth [1]. - Other common symptoms include **fatigue**, **weight gain**, **cold intolerance**, and **dry skin**. *Addison's disease* - This condition involves **adrenal insufficiency**, primarily causing symptoms like **hyperpigmentation**, low blood pressure, and fatigue. - **Hair loss** is generally not a prominent feature, and madarosis is not typically seen. *Acromegaly* - Characterized by excessive **growth hormone** production, leading to enlargement of hands, feet, and facial features. - While it can cause some changes in hair texture, **madarosis** is not a common clinical manifestation. *None of the options* - This option is incorrect because **Hypothyroidism** is a direct cause of madarosis due to its impact on **hair follicle metabolism** [1]. - The other conditions listed do not typically present with this specific type of eyebrow hair loss.

Question 1603: What condition is caused by the intake of exogenous steroids?

A. Addison's disease
B. Cushing's syndrome (Correct Answer)
C. Pheochromocytoma
D. Conn's syndrome

Explanation: ***Cushing's syndrome*** - **Exogenous steroid intake** is the most common cause of Cushing's syndrome, leading to symptoms associated with **excess cortisol** [1]. - This occurs because the steroids mimic the effects of **cortisol**, suppressing the body's natural production and leading to its characteristic signs and symptoms [2]. *Addison's disease* - This condition is characterized by **adrenal insufficiency**, meaning the adrenal glands produce too little **cortisol** and often **aldosterone**. - It is typically caused by autoimmune destruction of the adrenal glands, not by exogenous steroid intake. *Pheochromocytoma* - This is a rare tumor of the **adrenal medulla** that causes the overproduction of **catecholamines** (epinephrine and norepinephrine). - Symptoms include sudden, severe episodes of hypertension, palpitations, and sweating, unrelated to steroid intake. *Conn's syndrome* - Also known as **primary hyperaldosteronism**, this condition involves the overproduction of **aldosterone** by the adrenal glands. - It typically results in hypertension and hypokalemia and is not directly caused by exogenous steroid administration.

Question 1604: Among the following, most reliable test for screening of diabetes mellitus?

A. Urine sugar
B. Random sugar
C. Fasting sugar (Correct Answer)
D. Glucose tolerance test

Explanation: ***Fasting sugar*** - A **fasting plasma glucose** (FPG) test is the most common and reliable initial test for screening for **diabetes mellitus** because it measures blood glucose after an overnight fast (typically 8-12 hours), providing a baseline level unaffected by recent food intake [1]. - A fasting glucose level of **≥ 126 mg/dL** (7.0 mmol/L) on two separate occasions is diagnostic of diabetes, making it an excellent screening tool for identifying individuals with impaired glucose metabolism [1]. *Random sugar* - A random plasma glucose test can be used to diagnose diabetes if the level is **≥ 200 mg/dL** (11.1 mmol/L) in a symptomatic individual, but it is less reliable for screening asymptomatic individuals due to its variability depending on recent food intake [1]. - Because it can be measured at any time of day without regard to the last meal, it has a **lower sensitivity** for detecting early stages of diabetes compared to fasting glucose. *Glucose tolerance test* - An **oral glucose tolerance test** (OGTT) is highly sensitive and specific for diagnosing diabetes and impaired glucose tolerance, but it is more cumbersome and time-consuming, involving multiple blood draws over two hours after consuming a sugary drink. - While it is a definitive diagnostic test, its complexity makes it **less practical for routine screening** in large populations compared to simpler tests like fasting plasma glucose. *Urine sugar* - The presence of glucose in urine (glycosuria) indicates that blood glucose levels have exceeded the **renal threshold** (typically around 180 mg/dL), meaning the kidneys are unable to reabsorb all the glucose. - This is a **less sensitive and specific** method for screening, as it only becomes positive once blood glucose is significantly elevated, and it does not detect milder forms of impaired glucose metabolism or early diabetes.

Question 1605: Which condition is most commonly associated with systemic amyloidosis?

A. Chronic Kidney Disease (Correct Answer)
B. Multiple Myeloma
C. Rheumatoid Arthritis
D. Familial Mediterranean Fever

Explanation: Type II DM - Amyloidosis is commonly associated with **chronic diseases** like type II diabetes mellitus due to insulin resistance leading to amyloid deposition [4]. - The presence of **amiloid in the pancreas** often correlates with the complications of this type of diabetes [3]. *Maturity onset DM* - While maturity-onset diabetes can lead to complications, it is often synonymous with **type II DM**, making this distinction inaccurate regarding amyloidosis. - This term is less commonly used and does not emphasize the direct link to amyloidosis seen in type II diabetes. *HTN* - Hypertension itself is not a direct cause of amyloidosis; it typically results from other underlying conditions. - The association of amyloidosis with hypertension is usually **secondary**, not a primary condition leading to amyloid deposits [2]. *Type I DM* - Type I diabetes is primarily **autoimmune**, resulting in insulin-deficient states and does not strongly associate with amyloidosis like type II [1]. - The amyloid deposits seen in type I are much less common compared to type II or associated chronic conditions.

Question 1606: Which of the following is the MOST characteristic feature of insulinoma?

A. Hypoglycemic attacks (Correct Answer)
B. Usually Solitary tumour
C. Mostly benign tumour
D. Weight gain

Explanation: Hypoglycemic attacks - **Insulinoma** is a tumor of the pancreatic beta cells that secretes excessive insulin, leading to recurrent episodes of **hypoglycemia** [1]. - These attacks often occur during fasting or after exercise and are relieved by glucose intake [2]. Weight gain - While patients with insulinoma may experience some **weight gain** due to increased caloric intake to prevent hypoglycemic symptoms, it is not the most defining or characteristic feature. - Weight gain is a non-specific symptom that can be associated with many other conditions. Usually Solitary tumour - While many insulinomas are solitary (about 90%), this is a pathological characteristic rather than a clinical feature. - The patient's presentation is dominated by the **functional consequences** of insulin overproduction. Mostly benign tumour - Approximately 90% of insulinomas are benign, but this is a pathological classification. - The most characteristic clinical manifestation from a patient's perspective remains the recurrent **hypoglycemia** caused by excessive insulin secretion.

Question 1607: A 50-year-old woman, who is 5 feet 7 inches tall and weighs 185 pounds, has a family history of diabetes mellitus. Her fasting blood glucose levels are 160 mg/dL and 155 mg/dL on two occasions, and her HbA1c level is 7.9%. After being educated on medical nutrition therapy, she returns for reevaluation in 8 weeks, reporting that she has followed diet and exercise recommendations, but her fasting blood glucose levels remain between 140 and 150 mg/dL, and her HbA1c level is 7.7%. She is asymptomatic, and physical examination reveals no abnormalities. Which of the following treatments is the most appropriate for her condition?

A. Metformin (Correct Answer)
B. A thiazolidinedione
C. A dipeptidyl peptidase-4 (DPP-4) inhibitor
D. Insulin therapy

Explanation: ***Metformin*** - **Metformin** is the **first-line pharmacological treatment** for type 2 diabetes mellitus when lifestyle modifications are insufficient, as seen in this patient whose blood glucose and HbA1c remain elevated after 8 weeks of diet and exercise [1]. - It works by **decreasing hepatic glucose production** and **improving insulin sensitivity**, and it has a favorable safety profile, including no risk of hypoglycemia and potential for weight neutrality or modest weight loss [1]. *A thiazolidinedione* - **Thiazolidinediones** (e.g., pioglitazone) are effective in improving insulin sensitivity but are typically considered **second-line agents** or used in patients who cannot tolerate metformin. - They are associated with side effects such as **weight gain**, **fluid retention**, and an increased risk of heart failure, which might not be ideal for initial therapy. *A dipeptidyl ppetidase-4 (DPP-4) inhibitor* - **DPP-4 inhibitors** (e.g., sitagliptin) enhance insulin secretion and suppress glucagon secretion in a glucose-dependent manner, offering good glycemic control with a low risk of hypoglycemia. - However, they are **less potent** than metformin in lowering HbA1c and are generally used as **second-line therapy** or in combination with metformin. *Insulin therapy* - **Insulin therapy** is indicated for patients with **markedly elevated glucose levels** (e.g., HbA1c > 10% or fasting plasma glucose > 250 mg/dL), significant symptoms of hyperglycemia, or when other oral agents have failed. - This patient's HbA1c of 7.7% and asymptomatic status suggest that oral agents should be attempted first before resorting to insulin.

Question 1608: A patient presents with symptoms of hyperthyroidism. Thyroid function tests would probably reveal:

A. Increased T4, Increased T3, decreased TSH (Correct Answer)
B. Increased T4, normal T3, and increased TSH
C. Increased T3, T4, and increased TSH
D. Decreased T3 and T4, increased TSH

Explanation: ***Increased T4, Increased T3, decreased TSH*** - In **primary hyperthyroidism**, the thyroid gland overproduces thyroid hormones (**T3 and T4**), leading to elevated levels [1]. - The high levels of T3 and T4 then **feedback negatively** on the pituitary gland, suppressing the release of **TSH** [1]. *Increased T4, normal T3, and increased TSH* - This pattern is inconsistent with primary hyperthyroidism, as elevated T3 and T4 should suppress TSH. - An isolated increase in T4 with normal T3 can occur in **subclinical hyperthyroidism** or **thyroxine (T4) resistance**, but increased TSH would suggest pituitary dysfunction or resistance to thyroid hormones. *Increased T3, T4, and increased TSH* - Elevated T3 and T4 accompanied by **increased TSH** is a rare presentation, usually indicating **TSH-secreting pituitary adenoma** (secondary hyperthyroidism) or **thyroid hormone resistance** [1], [2]. - In typical hyperthyroidism, high thyroid hormone levels would suppress TSH. *Decreased T3 and T4, increased TSH* - This profile is characteristic of **primary hypothyroidism**, where an underactive thyroid gland produces insufficient T3 and T4 [1]. - The low thyroid hormone levels stimulate the pituitary to release **more TSH** in an attempt to stimulate thyroid hormone production [1].

Question 1609: A 30-year-old male presents with erectile dysfunction, low testosterone, and elevated prolactin levels. What is the most likely diagnosis?

A. Craniopharyngioma
B. Testicular failure
C. Pituitary adenoma (Correct Answer)
D. Cushing's syndrome

Explanation: Pituitary adenoma - Elevated prolactin levels in a male, coupled with symptoms of hypogonadism (erectile dysfunction, low testosterone), are highly suggestive of a prolactinoma, which is a type of pituitary adenoma [1]. - The prolactinoma suppresses gonadotropin-releasing hormone (GnRH), leading to secondary hypogonadism [1]. Craniopharyngioma - While it is a suprasellar tumor that can affect pituitary function, it typically causes symptoms related to compression of the optic chiasm (visual field defects) [3] and panhypopituitarism, which are not mentioned here. - Hyperprolactinemia is usually due to stalk compression rather than direct prolactin secretion, and other hormone deficiencies are typically more prominent [1]. Cushing's syndrome - Characterized by elevated cortisol levels, leading to symptoms like central obesity, moon facies, and skin changes, which are not described in this patient [4]. - Although it can sometimes be caused by a pituitary tumor (Cushing's disease), the primary hormonal imbalance is cortisol excess, not isolated hyperprolactinemia. Testicular failure - While it causes low testosterone and erectile dysfunction, it would lead to elevated LH and FSH (hypergonadotropic hypogonadism) due to the lack of negative feedback on the pituitary [2]. - Elevated prolactin is not a direct consequence of primary testicular failure.

Question 1610: What is the most common adrenal incidentaloma?

A. Aldosterone producing
B. Pheochromocytoma
C. Endocrine inactive tumors (Correct Answer)
D. Cortisol producing

Explanation: ***Endocrine inactive tumors*** - The majority, about **70-85%**, of adrenal incidentalomas are **benign, non-secretory adenomas**, which are often referred to as endocrine inactive tumors. [1] - These tumors do not produce excess hormones and are typically discovered incidentally on imaging performed for other reasons. *Cortisol producing* - While **cortisol-producing adenomas** are a type of functional adrenal tumor, they represent a smaller percentage of incidentalomas, usually less than 10%. - These can lead to **Cushing's syndrome**, but most incidentalomas causing hypercortisolism are subclinical. *Aldosterone producing* - **Aldosterone-producing adenomas**, which cause primary aldosteronism, are also less common than inactive tumors, accounting for about 1-5% of incidentalomas. [1] - They are typically associated with **hypertension** and **hypokalemia**. *Pheochromocytoma* - **Pheochromocytomas**, which secrete catecholamines, are rare adrenal incidentalomas, making up less than 5% of cases. - These tumors can cause **hypertension**, **tachycardia**, and other symptoms related to catecholamine excess. [1]

Practice by Chapter

Diabetes Mellitus

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Thyroid Disorders

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Adrenal Gland Disorders

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Pituitary Disorders

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Calcium and Bone Metabolism

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Reproductive Endocrinology

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Lipid Disorders

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Endocrine Hypertension

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Multiple Endocrine Neoplasia

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Obesity and Metabolic Syndrome

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Neuroendocrine Tumors

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Endocrine Emergencies

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