Endocrinology Practice Questions

Q: Investigation of choice in pheochromocytoma is:

Urinary catecholamines. ***Urinary catecholamines*** - Measurement of **24-hour urinary fractionated metanephrines and catecholamines** is the initial **biochemical test of choice**. - These biochemical tests are preferred over plasma levels due to the **episodic release** of hormones from a pheochromocytoma, which can lead to high false-negative rates in single plasma measurements. *CT scan* - While a **CT scan** is a crucial **imaging modality** for localizing a pheochromocytoma once the biochemical diagnosis is established [1], it is not the *initial* diagnostic investigation. - Imaging should be performed only after **biochemical confirmation** to avoid unnecessary investigations of incidental adrenal masses [1]. *MIBG scan* - An **MIBG scan** (metaiodobenzylguanidine scan) is a **functional imaging study** used primarily for **localizing metastatic pheochromocytomas** [1] or for cases where CT/MRI is equivocal. - It is not the initial investigation but rather a **secondary imaging test** [1]. *MRI Scan* - **MRI** is an alternative **imaging modality** to CT for localizing pheochromocytomas [1], especially in pregnant women or when radiation exposure is a concern. - Like CT, it serves as a **localization tool** after biochemical confirmation, not the diagnostic test itself.

Q: A pregnant woman is diagnosed with Graves' disease. The most appropriate therapy for her would be:

Propylthiouracil oral. ***Propylthiouracil oral*** - **Propylthiouracil (PTU)** is the preferred antithyroid drug during the **first trimester** of pregnancy due to a lower risk of teratogenicity compared to methimazole/carbimazole [1]. - It works by inhibiting both the synthesis of thyroid hormones and the peripheral conversion of **T4 to T3**. *Radioiodine therapy* - **Radioactive iodine** is absolutely contraindicated in pregnancy as it can cross the placenta and cause **fetal hypothyroidism or athyreosis**. - It leads to permanent destruction of the thyroid gland and is not suitable for a temporary condition in a pregnant woman. *Total thyroidectomy* - While thyroidectomy can be considered for Graves' disease in pregnancy, it is generally reserved for cases where antithyroid drugs are not tolerated or ineffective, or for very large goiters causing compressive symptoms. - It carries risks associated with **surgery and anesthesia** during pregnancy, and requires **lifelong thyroid hormone replacement**. *Carbimazole parenteral* - **Carbimazole** (which is metabolized to methimazole) is generally avoided in the **first trimester** due to an increased risk of teratogenicity, particularly **aplasia cutis**, omphalocele, and choanal atresia [1]. - While it can be used in the second and third trimesters, **PTU is preferred in the first trimester**, and carbimazole is not typically administered parenterally.

Q: What is the most characteristic symptom of pheochromocytoma?

Episodic hypertension. ***Episodic hypertension*** - This is the **most characteristic and consistent symptom**, occurring in nearly all patients [1]. It is caused by unpredictable surges in **catecholamine** release. - The hypertension can be paroxysmal (episodic) or sustained [1], but the episodic nature is a key diagnostic clue. *Headaches* - **Headaches** are a common symptom but are less specific to pheochromocytoma, as they can be caused by many conditions. - While headaches in pheochromocytoma can be severe and throbbing, they are an indirect result of the **hypertensive crisis**, not the primary defining feature. *Rapid heart rate* - **Tachycardia** (rapid heart rate) is a frequent manifestation due to **catecholamine** excess. - However, it often accompanies the hypertensive episodes and is not as universally characteristic or diagnostic as the **episodic hypertension** itself [1]. *Anxiety attacks* - Patients can experience symptoms mimicking **anxiety or panic attacks**, including profound apprehension, palpitations, and sweating. - While these can be prominent, they are typically secondary to the physiological effects of **catecholamine** surge and the resulting intense physical sensations, rather than the core diagnostic feature.

Q: Madarosis is seen in ?

Hypothyroidism. ***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.

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

Cushing's syndrome. ***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.

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

Fasting sugar. ***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.

Q: 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?

Metformin. ***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.

Q: Which of the following is the MOST characteristic feature of insulinoma?

Hypoglycemic attacks. 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.

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

Increased T4, Increased T3, decreased TSH. ***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].

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

Pituitary adenoma. 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 1

Investigation of choice in pheochromocytoma is:

Accepted Answer

Urinary catecholamines

Answer

CT scan

Answer

MIBG scan

Answer

MRI Scan

Question 2

A pregnant woman is diagnosed with Graves' disease. The most appropriate therapy for her would be:

Accepted Answer

Propylthiouracil oral

Answer

Radioiodine therapy

Answer

Total thyroidectomy

Answer

Carbimazole parenteral

Question 3

What is the most characteristic symptom of pheochromocytoma?

Accepted Answer

Episodic hypertension

Answer

Headaches

Answer

Rapid heart rate

Answer

Anxiety attacks

Question 4

Madarosis is seen in ?

Accepted Answer

Hypothyroidism

Answer

None of the options

Answer

Addison's disease

Answer

Acromegaly

Question 5

What condition is caused by the intake of exogenous steroids?

Accepted Answer

Cushing's syndrome

Answer

Addison's disease

Answer

Pheochromocytoma

Answer

Conn's syndrome

Question 6

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

Accepted Answer

Fasting sugar

Answer

Urine sugar

Answer

Random sugar

Answer

Glucose tolerance test

Question 7

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?

Accepted Answer

Metformin

Answer

A thiazolidinedione

Answer

A dipeptidyl peptidase-4 (DPP-4) inhibitor

Answer

Insulin therapy

Question 8

Which of the following is the MOST characteristic feature of insulinoma?

Accepted Answer

Hypoglycemic attacks

Answer

Usually Solitary tumour

Answer

Mostly benign tumour

Answer

Weight gain

Question 9

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

Accepted Answer

Increased T4, Increased T3, decreased TSH

Answer

Increased T4, normal T3, and increased TSH

Answer

Increased T3, T4, and increased TSH

Answer

Decreased T3 and T4, increased TSH

Question 10

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

Accepted Answer

Pituitary adenoma

Answer

Craniopharyngioma

Answer

Testicular failure

Answer

Cushing's syndrome

Endocrinology — MCQs

Endocrinology — MCQs

On this page

Practice by Chapter

Want unlimited practice?