Endocrinology Practice Questions

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.

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: Which condition is most commonly associated with non-pitting edema?

Myxedema (Hypothyroidism). ***Myxedema (Hypothyroidism)*** - Non-pitting edema in myxedema is caused by the accumulation of **hyaluronic acid** and other glycosaminoglycans in the interstitial tissue [2]. - This accumulation creates a **gel-like matrix** that does not pit when pressed, distinguishing it from other forms of edema. *Congestive heart failure (CHF)* - CHF typically causes **pitting edema** due to increased hydrostatic pressure, leading to fluid extravasation into the interstitial space. - The excess fluid is primarily water and electrolytes, allowing for displacement upon pressure. *Liver cirrhosis* - Liver cirrhosis leads to **pitting edema**, often in the lower extremities and abdomen (**ascites**), due to decreased albumin synthesis and portal hypertension. - The reduced oncotic pressure and increased hydrostatic pressure result in fluid leakage that is easily compressible [1]. *Nephrotic syndrome* - Nephrotic syndrome is characterized by **pitting edema**, which is widespread (**anasarca**) and primarily caused by severe **hypoalbuminemia** [1]. - The significant loss of protein in the urine reduces plasma oncotic pressure, leading to fluid accumulation that readily pits with pressure.

Q: In which of the following situations is intensive management of diabetes typically avoided?

Diabetes with acute myocardial infarction. Diabetes with acute myocardial infarction - In the setting of **acute myocardial infarction (AMI)**, aggressive **glucose lowering** can increase the risk of **hypoglycemia** and is generally avoided due to potential for worse outcomes [1]. - The primary focus in AMI is on cardiovascular stabilization, and overly tight glycemic control can lead to **metabolic stress** and adverse events, particularly in patients with a high prevalence of cardiovascular disease [1]. *Stable diabetes with no complications* - Patients with **stable diabetes** and no complications are often candidates for **intensive management** to prevent long-term microvascular and macrovascular complications [1]. - The goal is to maintain near-normal glucose levels to reduce the risk of future disease progression [1]. *Diabetes in a well-controlled state* - **Well-controlled diabetes** usually indicates that current management is effective, but further **intensification** might be considered to achieve optimal glycemic targets and minimize long-term risks if there's room for improvement. - This scenario does not inherently contraindicate intensive management, as it could still benefit from fine-tuning to achieve even tighter control without undue risk. *Diabetes with stable renal function post-transplant* - Patients with **diabetes** and stable **renal function post-transplant** often require careful but often intensive diabetes management to preserve graft function and prevent cardiovascular complications. - While medication adjustments are necessary due to altered renal clearance, the goal remains to achieve good glycemic control, potentially through intensive strategies.

Q: True regarding glucose tolerance test are all except:

1 gram of glucose/kg body weight is administered. ***1 gram of glucose/kg body weight is administered*** - For an oral glucose tolerance test (OGTT) in adults, the standard dose is **75 grams of anhydrous glucose**, irrespective of body weight. [3] - In children, the recommended dose is **1.75 g/kg body weight** up to a maximum of 75 grams. *Glucose levels are checked after 2 hours* - This statement is **true** for a standard oral glucose tolerance test, where post-load glucose levels are typically measured at 2 hours to assess glucose metabolism. [3] - The **2-hour plasma glucose value** is a key diagnostic criterion for diabetes and impaired glucose tolerance. [1] *Diagnosis of diabetes mellitus can be established* - This statement is **true**, as an OGTT is a standard diagnostic tool for diabetes mellitus and impaired glucose tolerance. [1] - A 2-hour plasma glucose level of **200 mg/dL (11.1 mmol/L) or higher** during an OGTT confirms a diagnosis of diabetes. [1] *Can be done in fasting as well as post prandial state* - This statement refers to the **timing of the blood samples**, not the preparation for the test itself. Fasting plasma glucose is measured before glucose ingestion, while post-prandial levels are assessed after the glucose load. [2] - However, for an OGTT to be valid, the patient must be in a **fasting state** for at least 8 hours prior to the test to establish a baseline.

Q: A 13-year-old child visits the OPD with complaints of not attaining menarche, and has a karyotype of 46,XX. On examination, there is clitoromegaly. Which enzyme is likely deficient?

21-alpha hydroxylase. ***21-alpha hydroxylase*** - A deficiency in **21-alpha hydroxylase** leads to **Congenital Adrenal Hyperplasia (CAH)**, shunting precursors towards **androgen production**. - In a 46,XX individual, this results in **virilization** such as **clitoromegaly** and **primary amenorrhea** due to excess androgens suppressing gonadotropin release and ovarian function. *17-alpha hydroxylase* - Deficiency in **17-alpha hydroxylase** in a 46,XX individual would lead to impaired sex steroid synthesis but **excess mineralocorticoids**, causing **hypertension** and **hypokalemia**. - While it causes **primary amenorrhea** due to lack of estrogen, it typically presents with **female external genitalia** that are underdeveloped, not virilized with clitoromegaly. *11-alpha hydroxylase* - There is no known functional enzyme called **11-alpha hydroxylase** in the steroid synthesis pathway. The relevant enzyme is **11-beta hydroxylase**, which, when deficient, leads to **CAH** with virilization and hypertension. - Assuming it refers to 11-beta hydroxylase, deficiency would cause **virilization** in 46,XX females but also lead to **hypertension** due to accumulation of 11-deoxycorticosterone, which is not mentioned in the presentation. *3-beta hydroxysteroid dehydrogenase* - Deficiency of **3-beta hydroxysteroid dehydrogenase** impairs the synthesis of **all classes of adrenal steroids** (glucocorticoids, mineralocorticoids, and sex steroids). - In 46,XX individuals, it leads to **females with ambiguous genitalia** (due to accumulation of DHEA) and **salt wasting**, but typically does not cause overt clitoromegaly and amenorrhea in the manner seen with 21-hydroxylase deficiency.

Q: Which of the following is the most common feature of thyrotoxicosis?

Anxiety. ***Anxiety*** - **Anxiety** and **nervousness** are highly prevalent neurobehavioral symptoms in thyrotoxicosis, occurring in a majority of patients due to increased adrenergic activity [1]. - Patients often present with **irritability**, **restlessness**, and difficulty concentrating, which are all manifestations of anxiety. *Palpitation* - While very common, **palpitations** (tachycardia) are a cardiac manifestation due to increased heart rate and contractility, but are not universally present or the sole dominant symptom in all cases [2]. - Many patients experience **palpitations** but may present with other symptoms more prominently in the initial stages. *Weight loss* - **Weight loss** despite an increased appetite is a classic symptom of thyrotoxicosis due to an elevated metabolic rate [1], [2]. - However, not all patients experience significant **weight loss**, especially those with milder or subclinical disease. *Menorrhagia* - **Menorrhagia** (heavy menstrual bleeding) is typically *not* a feature of thyrotoxicosis; in fact, **oligomenorrhea** (infrequent periods) or **amenorrhea** (absence of periods) are more commonly associated due to hormonal imbalances. - Thyroid hormones play a role in regulating the menstrual cycle, and excess thyroid hormone often leads to lighter or absent periods.

Q: While investigating a case of gynecomastia, all of the following hormone levels are estimated, except:

Follicle stimulating hormone. ***Follicle stimulating hormone*** - While **FSH** levels can be assessed in cases of infertility or hypogonadism, they are generally **not a primary assessment** for gynecomastia. - The direct hormonal imbalance causing gynecomastia typically involves other hormones like testosterone, estrogen, LH, and prolactin. *Lutenizing hormone* - **LH** levels are crucial in assessing **gonadal function** and identifying the cause of altered testosterone production, which is directly linked to gynecomastia [1]. - Elevated or suppressed LH can indicate primary or secondary hypogonadism affecting the **testosterone-estrogen balance**. *Prolactin* - **Prolactin** levels are important to rule out **hyperprolactinemia**, which can lead to hypogonadism and subsequently gynecomastia [1]. - A **prolactinoma** (prolactin-secreting tumor) can suppress GnRH, leading to reduced testosterone and an increased estrogen-to-androgen ratio [1]. *None of the options* - This option is incorrect because there is a specific hormone (FSH) among the choices that is **less commonly estimated** in the initial workup for gynecomastia compared to LH and prolactin. - The workup for gynecomastia commonly involves assessment of other hormones like **testosterone** and **estrogen** along with LH and prolactin [1].

Q: Which of the following conditions is not associated with Cushing syndrome?

Medulloblastoma. ***Medulloblastoma*** - **Medulloblastoma** is a primary **brain tumor** that arises in the cerebellum and is not typically associated with hormone production leading to Cushing syndrome. - Its symptoms are primarily neurological, related to increased **intracranial pressure** or cerebellar dysfunction, not systemic metabolic disturbances. *Adrenal carcinoma* - **Adrenal carcinoma** can directly produce excessive amounts of **cortisol**, leading to Cushing syndrome (specifically **primary adrenal Cushing's**) [1]. - This is a rare but aggressive tumor of the adrenal cortex. *Oat cell carcinoma of lung* - Also known as **small cell lung carcinoma**, this tumor can produce **ectopic ACTH** (adrenocorticotropic hormone), leading to paraneoplastic Cushing syndrome [1]. - The ectopic ACTH stimulates the adrenal glands to produce excess cortisol [1]. *Pituitary adenoma* - A **pituitary adenoma** that secretes ACTH is the most common cause of **Cushing's disease** (a specific type of Cushing syndrome) [1]. - This excess ACTH then stimulates the adrenal glands to overproduce cortisol [1].

Question 1

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

Question 2

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 3

A 45-year-old man with a recent history of bizarre behavior is seen by a psychiatrist. On physical examination, the patient appears moderately obese with mild hypertension, facial acne, and fat accumulation in the supraclavicular fossae. Laboratory studies demonstrate neutrophilic leukocytosis, decreased lymphocytes, and absence of eosinophils, along with mild hypokalemia and mild metabolic alkalosis. The fasting serum glucose is within the reference range, but the OGTT shows glucose concentrations > 200 mg/dL. Laboratory studies also show a free urinary cortisol of 156 mg/24 hours. Which of the following questions would be of most help in establishing a diagnosis?

Accepted Answer

Are you receiving corticosteroids for some other disease?

Answer

Are you experiencing muscle weakness?

Answer

Do you have a family history of endocrine neoplasia?

Answer

Are you experiencing shortness of breath?

Question 4

Which condition is most commonly associated with non-pitting edema?

Accepted Answer

Myxedema (Hypothyroidism)

Answer

Congestive heart failure (CHF)

Answer

Liver cirrhosis

Answer

Nephrotic syndrome

Question 5

In which of the following situations is intensive management of diabetes typically avoided?

Accepted Answer

Diabetes with acute myocardial infarction

Answer

Stable diabetes with no complications

Answer

Diabetes in a well-controlled state

Answer

Diabetes with stable renal function post-transplant

Question 6

True regarding glucose tolerance test are all except:

Accepted Answer

1 gram of glucose/kg body weight is administered

Answer

Diagnosis of diabetes mellitus can be established

Answer

Glucose levels are checked after 2 hours

Answer

Can be done in fasting as well as post prandial state

Question 7

A 13-year-old child visits the OPD with complaints of not attaining menarche, and has a karyotype of 46,XX. On examination, there is clitoromegaly. Which enzyme is likely deficient?

Accepted Answer

21-alpha hydroxylase

Answer

17-alpha hydroxylase

Answer

11-alpha hydroxylase

Answer

3-beta hydroxysteroid dehydrogenase

Question 8

Which of the following is the most common feature of thyrotoxicosis?

Accepted Answer

Anxiety

Answer

Weight loss

Answer

Menorrhagia

Answer

Palpitation

Question 9

While investigating a case of gynecomastia, all of the following hormone levels are estimated, except:

Accepted Answer

Follicle stimulating hormone

Answer

Lutenizing hormone

Answer

Prolactin

Answer

None of the options

Question 10

Which of the following conditions is not associated with Cushing syndrome?

Accepted Answer

Medulloblastoma

Answer

Oat cell carcinoma of lung

Answer

Pituitary adenoma

Answer

Adrenal carcinoma

Endocrinology — MCQs

Endocrinology — MCQs

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