Endocrinology Practice Questions

Q: All of the following are features of hypothyroidism except which of the following?

Lid retraction. ***Lid retraction*** - **Lid retraction** is a characteristic feature of **hyperthyroidism** (e.g., Graves' disease), not hypothyroidism [1]. - It results from increased sympathetic stimulation of the **Müller's muscle** and/or superior rectus muscle overactivity. *Cold intolerance* - **Cold intolerance** is a common symptom of **hypothyroidism** due to a reduced metabolic rate and decreased heat production [2]. - The body's ability to maintain core temperature is impaired, leading to increased sensitivity to cold environments. *Dry skin* - **Dry, scaly skin** (xerosis) is a frequent manifestation of **hypothyroidism**. - It is caused by decreased sebaceous and sweat gland activity, as well as changes in epidermal cell turnover. *Myxedema* - **Myxedema** refers to the characteristic non-pitting edema seen in severe or long-standing **hypothyroidism** [2]. - It results from the accumulation of **glycosaminoglycans** (e.g., hyaluronic acid) in the interstitial spaces, leading to swelling, particularly in the face, hands, and feet [1].

Q: Hypercalcemia is not a feature of which one of the following conditions?

Tumor lysis syndrome. Tumor lysis syndrome is characterized by the rapid breakdown of tumor cells, leading to the release of intracellular contents. This typically causes **hyperkalemia**, **hyperphosphatemia**, and **hyperuricemia**, but generally **hypocalcemia** due to phosphate binding [3], not hypercalcemia. *Primary hyperparathyroidism* - This condition involves excessive production of **parathyroid hormone (PTH)**, which leads to increased bone resorption, increased renal calcium reabsorption, and increased vitamin D activation, all contributing to **hypercalcemia** [1], [4]. - It is a common cause of isolated elevated calcium levels, often discovered incidentally [2]. *Multiple myeloma* - Multiple myeloma is a plasma cell malignancy that causes extensive **bone destruction** through the release of osteoclast-activating factors. - This increased bone resorption leads to a significant release of calcium into the bloodstream, resulting in **hypercalcemia** [1]. *Sarcoidosis* - Sarcoidosis is a granulomatous disease where activated macrophages in the granulomas produce **1,25-dihydroxyvitamin D** (calcitriol). - This excess calcitriol leads to increased intestinal absorption of calcium and increased bone resorption, causing **hypercalcemia** [1].

Q: Which of the following conditions is least likely to cause weight loss?

Insulinoma. ***Insulinoma*** - An **insulinoma** is a tumor of the pancreatic beta cells that secretes excessive insulin, leading to **hypoglycemia**. - While patients may experience weight gain due to frequent eating to counteract hypoglycemic episodes, significant weight loss is **uncommon** and not a primary feature [1]. *Pheochromocytoma* - **Pheochromocytoma** is a tumor that secretes high levels of **catecholamines** (epinephrine and norepinephrine), which increase metabolic rate. - This increased metabolism often leads to significant **weight loss**, along with symptoms like hypertension, palpitations, and sweating. *Adrenal insufficiency* - **Adrenal insufficiency** (Addison's disease) is characterized by decreased production of cortisol and aldosterone, leading to chronic GI symptoms, weakness, and **anorexia**. - Patients often experience **unexplained weight loss** due to nausea, vomiting, and loss of appetite. *Uremia* - **Uremia** refers to the accumulation of urea and other nitrogenous waste products in the blood, typically seen in advanced **kidney failure**. - It often causes symptoms like **anorexia**, nausea, vomiting, and a metallic taste in the mouth, all of which contribute to significant **weight loss**.

Q: Most common cause of Cushing's syndrome is what?

Pituitary adenoma. ***Pituitary adenoma*** - The **most common cause** of Cushing's syndrome, specifically **Cushing's disease**, is excess ACTH production from a pituitary adenoma [1]. - This leads to **overstimulation of the adrenal glands**, resulting in increased cortisol production [1]. *McCune Albright syndrome* - It is a genetic disorder characterized by **fibrous dysplasia**, **café-au-lait spots**, and **endocrine problems**, not primarily Cushing's syndrome. - Though hormone abnormalities may present, it is not the **most common** cause of Cushing's syndrome. *Adrenal carcinoma* - While adrenal carcinoma can cause **Cushing's syndrome**, it is less common compared to the **pituitary adenoma** [1]. - This malignant tumor is rare and typically presents with more aggressive features and higher cortisol levels. *Adrenal adenoma* - Adrenal adenomas are benign tumors that can produce **excess cortisol**, but they are not the leading cause of Cushing's syndrome overall [1]. - They account for a smaller proportion of cases compared to **pituitary adenomas**.

Q: A hypertensive patient who is a chronic smoker presented with recurrent hemoptysis, and on examination, he had cushingoid features. Investigations revealed raised ACTH levels that were not suppressed by dexamethasone. The single diagnosis that can account for all his symptoms is

Ectopic ACTH-producing tumor. ***Ectopic ACTH-producing tumor*** - The combination of **Cushingoid features**, **recurrent hemoptysis** (suggesting a lung tumor), **hypertension**, elevated **ACTH levels**, and non-suppressibility by **dexamethasone** strongly points to an **ectopic ACTH-producing tumor**, most commonly a small cell lung carcinoma [1], [2]. - The patient's **chronic smoking history** further increases the likelihood of a paraneoplastic syndrome associated with lung cancer. *Multiple endocrine neoplasia type I* - MEN 1 involves tumors of the parathyroid glands, pituitary gland, and pancreas, leading to symptoms like **hypercalcemia**, **acromegaly**, or **Zollinger-Ellison syndrome**. - While pituitary tumors can cause Cushing's disease, the **hemoptysis** and **chronic smoking history** are not typical features of MEN 1. *Adrenocortical adenoma* - An **adrenocortical adenoma** would cause **Cushing's syndrome** due to primary adrenal cortisol overproduction, leading to **suppressed ACTH levels** rather than elevated levels [1], [2]. - It would not explain the **hemoptysis** or the non-suppressibility of ACTH by dexamethasone. *Cushing's disease due to pituitary adenoma* - **Cushing's disease** is caused by a **pituitary adenoma** secreting ACTH, leading to elevated ACTH and cortisol levels [1]. - While it causes **Cushingoid features** and **hypertension**, it would typically show partial suppression of **ACTH** with high-dose dexamethasone and does not explain the **hemoptysis**.

Q: As per the etiological classification of diabetes mellitus, gestational diabetes mellitus is

Type IV. ***Type IV*** - According to the **etiological classification of diabetes mellitus**, gestational diabetes mellitus (GDM) is classified as **Type IV** [1]. - GDM is specifically defined as **diabetes diagnosed during pregnancy** that is not clearly overt diabetes prior to gestation [2]. *Type IA* - Type IA diabetes refers to **autoimmune Type 1 Diabetes**, characterized by immune-mediated destruction of pancreatic beta cells [1]. - This form of diabetes typically presents in childhood or adolescence and is associated with **autoantibodies** against islet cells. *Type IB* - Type IB diabetes refers to **idiopathic Type 1 Diabetes**, which is a form of Type 1 diabetes where there is no evidence of autoimmunity [1]. - It is rare and primarily seen in individuals of African or Asian descent, distinguished by a lack of **autoimmune markers**. *Type II* - Type II diabetes is characterized by **insulin resistance** and a progressive loss of insulin secretion, typically diagnosed in adults. - While GDM shares some physiological characteristics with Type II diabetes, it is a distinct *classification* due to its onset specific to **pregnancy** [2].

Q: ACTH reserve is best assessed by which test?

Insulin-induced hypoglycemia. ***Insulin-induced hypoglycemia*** - This test is considered the **gold standard** for assessing ACTH reserve because the resulting **severe stress** is the most potent physiological stimulus for both ACTH and growth hormone secretion [1]. - A healthy pituitary gland will respond to the stress of hypoglycemia by significantly increasing ACTH and cortisol levels; a blunted response indicates **adrenal insufficiency** or **pituitary dysfunction** [1]. *Corticotropin-releasing hormone (CRH) test* - The CRH test assesses the **pituitary's response to CRH** in releasing ACTH, helping to distinguish between primary and secondary adrenal insufficiency. - While it evaluates ACTH secretion, it does not assess the overall functional reserve of the HPA axis to a strong physiological stressor as effectively as insulin-induced hypoglycemia. *ACTH stimulation test* - The ACTH stimulation test, or **cosyntropin stimulation test**, directly evaluates the **adrenal gland's capacity to produce cortisol** in response to exogenous ACTH [2]. - This test assesses primary adrenal insufficiency, but it does not evaluate the **pituitary gland's ability to release ACTH** (ACTH reserve) [2]. *Glucocorticoid levels assessment* - Measuring baseline glucocorticoid (cortisol) levels provides a snapshot of adrenal function at a single point in time, but it does not assess the **reserve or responsiveness of the HPA axis** to stress [1]. - For a more accurate assessment, these levels need to be interpreted in the context of diurnal variation or dynamic testing [1].

Q: Which antibodies are primarily associated with Graves' disease?

TSH receptor antibodies (TRAb). ***TSH receptor antibodies (TRAb)*** - **TRAb** directly stimulate the **TSH receptor** on thyroid follicular cells, leading to excessive thyroid hormone production and the characteristic features of **Graves' disease** [1], [2]. - These antibodies are highly specific for Graves' disease and are used for diagnosis, management, and prediction of remission [1]. *Antinuclear antibodies (ANA)* - **ANA** are associated with various **systemic autoimmune diseases** like lupus and scleroderma, not primarily with Graves' disease. - While ANA can be positive in a small percentage of Graves' patients due to general immune dysregulation, they are not the causative or primary diagnostic antibody. *Thyroid peroxidase antibodies (TPO)* - **TPO antibodies** are primarily associated with **Hashimoto's thyroiditis**, causing thyroid destruction and hypothyroidism. - Although they can be present in Graves' disease, they are not the main pathogenic antibodies responsible for hyperthyroidism. *Anti-thyroglobulin antibodies* - **Anti-thyroglobulin antibodies** are also mainly associated with **Hashimoto's thyroiditis** and other autoimmune thyroid conditions. - They target thyroglobulin, a precursor to thyroid hormones, but do not directly stimulate thyroid hormone synthesis as TRAb do in Graves' disease.

Q: Which assay is primarily used to assess growth hormone levels?

Growth hormone stimulation test. ***Growth hormone stimulation test*** - This is the primary diagnostic assay to evaluate **growth hormone (GH) deficiency** or excess, as GH levels fluctuate throughout the day. - Various stimuli, such as **insulin-induced hypoglycemia**, **arginine**, or **clonidine**, are used to trigger GH release, and levels are measured serially [1]. *Diabetes mellitus* - This is a metabolic disorder characterized by **elevated blood glucose levels** due to insulin deficiency or resistance, not an assay for growth hormone. - While growth hormone can affect glucose metabolism, diabetes mellitus describes a **disease state**, not a diagnostic test for growth hormone levels [2]. *Glucagon assay* - A glucagon assay measures the level of **glucagon**, a hormone produced by the pancreas that raises blood glucose levels. - While glucagon can be used in some stimulation tests for growth hormone, a "glucagon assay" alone is not the primary method to assess overall growth hormone status. *Catecholamines* - Catecholamines are a group of hormones, including **epinephrine (adrenaline)**, **norepinephrine**, and **dopamine**, which are involved in the body's stress response. - Assays for catecholamines are used to diagnose conditions like **pheochromocytoma** or neuroblastoma, not to assess growth hormone levels.

Q: Which of the following statements is true regarding testicular feminization syndrome (androgen insensitivity syndrome)? a) Testes are present, b) Female habitus, c) XY genotype, d) Uterus present.

Presence of testes, female phenotype, and XY genotype.. ***Presence of testes, female phenotype, and XY genotype.*** - Testicular feminization syndrome, or **androgen insensitivity syndrome (AIS)**, is characterized by an **XY genotype** (chromosomal male) with a **female phenotype** due to the body's inability to respond to androgens. - Individuals with AIS possess **testes**, which produce androgens, but the target cells lack functional androgen receptors, leading to feminization. *Testes are present and XY genotype.* - While correct that **testes are present** and the genotype is **XY**, this option is incomplete as it doesn't mention the striking feature of the female phenotype. - The core of the syndrome is the discrepancy between the genetic sex and the external appearance, which is not fully captured. *Female phenotype with XY genotype.* - This statement is accurate regarding the **phenotype** and **genotype** but omits the presence of internal gonads (testes), which is a key diagnostic feature. - The presence of female external characteristics despite a male genotype is central to the diagnosis and understanding of AIS. *Presence of uterus and XY genotype.* - This statement is incorrect because individuals with complete androgen insensitivity syndrome **do not have a uterus**. - The **Müllerian inhibiting factor** produced by the testes during fetal development causes the regression of Müllerian ducts, preventing uterus formation.

Question 1

All of the following are features of hypothyroidism except which of the following?

Accepted Answer

Lid retraction

Answer

Dry skin

Answer

Myxedema

Answer

Cold intolerance

Question 2

Hypercalcemia is not a feature of which one of the following conditions?

Accepted Answer

Tumor lysis syndrome

Answer

Primary hyperparathyroidism

Answer

Multiple myeloma

Answer

Sarcoidosis

Question 3

Which of the following conditions is least likely to cause weight loss?

Accepted Answer

Insulinoma

Answer

Pheochromocytoma

Answer

Adrenal insufficiency

Answer

Uremia

Question 4

Most common cause of Cushing's syndrome is what?

Accepted Answer

Pituitary adenoma

Answer

Adrenal adenoma

Answer

Adrenal carcinoma

Answer

McCune Albright syndrome

Question 5

A hypertensive patient who is a chronic smoker presented with recurrent hemoptysis, and on examination, he had cushingoid features. Investigations revealed raised ACTH levels that were not suppressed by dexamethasone. The single diagnosis that can account for all his symptoms is

Accepted Answer

Ectopic ACTH-producing tumor

Answer

Adrenocortical adenoma

Answer

Multiple endocrine neoplasia type I

Answer

Cushing's disease due to pituitary adenoma

Question 6

As per the etiological classification of diabetes mellitus, gestational diabetes mellitus is

Accepted Answer

Type IV

Answer

Type IA

Answer

Type IB

Answer

Type II

Question 7

ACTH reserve is best assessed by which test?

Accepted Answer

Insulin-induced hypoglycemia

Answer

Corticotropin-releasing hormone (CRH) test

Answer

ACTH stimulation test

Answer

Glucocorticoid levels assessment

Question 8

Which antibodies are primarily associated with Graves' disease?

Accepted Answer

TSH receptor antibodies (TRAb)

Answer

Antinuclear antibodies (ANA)

Answer

Thyroid peroxidase antibodies (TPO)

Answer

Anti-thyroglobulin antibodies

Question 9

Which assay is primarily used to assess growth hormone levels?

Accepted Answer

Growth hormone stimulation test

Answer

Diabetes mellitus

Answer

Glucagon assay

Answer

Catecholamines

Question 10

Which of the following statements is true regarding testicular feminization syndrome (androgen insensitivity syndrome)? a) Testes are present, b) Female habitus, c) XY genotype, d) Uterus present.

Accepted Answer

Presence of testes, female phenotype, and XY genotype.

Answer

Female phenotype with XY genotype.

Answer

Testes are present and XY genotype.

Answer

Presence of uterus and XY genotype.

Endocrinology — MCQs

Endocrinology — MCQs

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