Endocrinology Practice Questions

Q: A young patient presented with hypertension and a 24-hour urinary metanephrine level of 1.4 mg, the most likely causes are -

VonHippelLindau syndrome. ***Von Hippel-Lindau syndrome*** - This syndrome is a **hereditary condition** predisposing individuals to various tumors, including **pheochromocytomas**, which cause elevated **metanephrines** and hypertension. - The combination of **hypertension** in a young patient and an elevated **24-hour urinary metanephrine level** (indicating excessive catecholamine production) strongly suggests a pheochromocytoma, which is frequently associated with Von Hippel-Lindau syndrome. *Medullary carcinoma thyroid* - This cancer is associated with **MEN 2 syndromes** and produces **calcitonin**, leading to hypocalcemia, but not typically elevated metanephrines or hypertension directly from the thyroid. - While it can be associated with **pheochromocytoma** (as part of MEN 2), it is not the direct cause of the elevated metanephrines. *Grave's disease* - **Grave's disease** is an autoimmune disorder causing **hyperthyroidism**, characterized by symptoms like goiter, exophthalmos, and weight loss. - While it can cause hypertension due to increased cardiac output, it does not lead to elevated **urinary metanephrine levels**, which are specific to catecholamine excess. *Pseudohypoparathyroidism* - This is a genetic disorder characterized by **target organ resistance to parathyroid hormone (PTH)**, leading to hypocalcemia and hyperphosphatemia [1]. - It does not cause hypertension or elevated **urinary metanephrine levels**.

Q: Hot flushes are not associated with which of the following?

Radical prostatectomy. ***Radical prostatectomy*** - This procedure surgically removes the prostate gland but **does not directly impact hormone levels** that cause hot flushes. - While it treats prostate cancer, it does not induce **androgen deprivation**, which is the primary cause of hot flushes in men. *Medical castration* - This refers to the use of drugs (e.g., **GnRH agonists/antagonists**) to **suppress testosterone production** or action. - The resulting low testosterone levels commonly lead to symptoms like **hot flushes**, similar to menopause in women. *Surgical castration* - This involves the surgical removal of the testes (orchiectomy), which are the primary source of testosterone in men. - The sudden and significant **drop in testosterone** after orchiectomy frequently causes **hot flushes**. *Ketoconazole therapy* - **Ketoconazole** is an antifungal medication that, at high doses, can **inhibit adrenal and gonadal steroid synthesis**, including testosterone. - This leads to a state of **chemical castration** with a decrease in testosterone, often resulting in **hot flushes** as a side effect.

Q: Which of the following is the most prominent clinical manifestation of primary hyperaldosteronism (Conn's syndrome)?

Hypertension. ** Hypertension** - **Hypertension** is the most prominent and consistent clinical manifestation of primary hyperaldosteronism, present in nearly all patients. - The excessive aldosterone leads to increased **sodium reabsorption** and water retention, directly causing elevated blood pressure [2], [3]. *Hypokalemia* - While **hypokalemia** is common in primary hyperaldosteronism due to increased renal potassium excretion, it is not universally present and can be absent in a significant portion of patients (up to 30-50%). - Therefore, hypertension is a more reliable and prominent symptom for initial suspicion [3]. *Hyperkalemia* - **Hyperkalemia** is inconsistent with primary hyperaldosteronism; the hallmark of the condition is **potassium wasting** and **hypokalemia**, not elevated potassium levels [2]. - Aldosterone's primary role includes promoting potassium excretion, so hyperkalemia would indicate a different underlying pathology, such as adrenal insufficiency [2]. *Expansion of Extracellular and Plasma volume* - While increased aldosterone does lead to **expansion of extracellular and plasma volume** due to sodium and water retention, this is a physiological consequence that contributes to hypertension rather than being the most prominent *clinical manifestation* itself [1]. - Hypertension is the direct observable and measurable clinical symptom that drives investigation [3].

Q: What is the most common cause of hypercalcemia in outpatient settings?

Primary hyperparathyroidism. **Primary hyperparathyroidism** - Accounts for the majority of hypercalcemia cases in **outpatient settings** (up to 90%). [1] - It is characterized by the **excessive secretion of parathyroid hormone (PTH)** from one or more parathyroid glands, leading to increased serum calcium levels. [1], [2] *Malignancy* - While it is the most common cause of hypercalcemia in **inpatient settings**, it is less frequent than primary hyperparathyroidism in outpatients. [1] - Often associated with **parathyroid hormone-related peptide (PTHrP)** secretion or bone metastases. [1] *Vitamin D toxicity* - This is a rare cause of hypercalcemia, usually resulting from **excessive supplementation** or medication error. [1] - It leads to increased intestinal calcium absorption and bone resorption, but is not as common as primary hyperparathyroidism. *Thiazide diuretics* - These medications can cause **mild hypercalcemia** by increasing renal calcium reabsorption. [1] - However, the hypercalcemia is typically mild and rarely as significant as that seen in primary hyperparathyroidism or malignancy.

Q: A 45-year-old woman presents with increased testosterone levels and temporal hair recession. What is the most likely diagnosis?

Polycystic Ovary Syndrome (PCOS). Polycystic Ovary Syndrome (PCOS) - PCOS is characterized by hormonal imbalances, leading to elevated androgen (testosterone) levels, which can cause symptoms like hirsutism (excess body hair), acne, and temporal hair recession in women [1]. - The elevated testosterone levels directly explain the temporal hair recession, which is a common manifestation of androgen excess in PCOS [1]. Osteoporosis - Osteoporosis is a condition of decreased bone density and increased fracture risk. - It is primarily related to estrogen deficiency and typically does not involve increased testosterone levels or temporal hair recession. Rheumatoid arthritis - Rheumatoid arthritis is an autoimmune inflammatory disease primarily affecting the joints. - It does not cause increased testosterone levels or temporal hair recession. Granulosa theca cell tumour - While granulosa cell tumors can produce hormones, they are more commonly associated with estrogen production and present with symptoms like abnormal uterine bleeding. - Although theca cell tumors can produce androgens, they are rare and typically present with more severe and rapid onset of virilization compared to the chronic presentation implied by the question [1].

Q: Bones, stones, abdominal groans, and psychiatric overtones are features of?

Hyperparathyroidism. ***Hyperparathyroidism*** - This mnemonic ("**bones, stones, abdominal groans, and psychiatric overtones**") perfectly describes the classic manifestations of **hypercalcemia** due to hyperparathyroidism [1]. - **Bones** refers to bone pain from increased osteoclastic activity [1], **stones** to kidney stones [1], **abdominal groans** to GI symptoms like constipation or pancreatitis [1], and **psychiatric overtones** to neuropsychiatric symptoms like depression or confusion. *Hyperthyroidism* - Characterized by symptoms of an **overactive metabolism**, such as weight loss, heat intolerance, tremor, and tachycardia [1]. - It does not typically present with the "bones, stones, and groans" triad associated with calcium imbalances. *Hypothyroidism* - Involves symptoms of an **underactive metabolism**, including weight gain, cold intolerance, fatigue, and bradycardia. - While it can cause some psychiatric symptoms (e.g., depression), it does not involve issues like kidney stones or significant bone problems from hypercalcemia. *Hypoparathyroidism* - Leads to **hypocalcemia**, presenting with symptoms like **tetany**, muscle cramps, paresthesias, and seizures. - This is the opposite of hyperparathyroidism and would not cause the symptoms listed in the mnemonic.

Q: Nelson's syndrome is most likely seen after removal of both adrenal glands.

Adrenalectomy. ***Adrenalectomy*** - Nelson's syndrome develops in some patients following bilateral **adrenalectomy** performed for **Cushing's disease**. - The removal of the adrenal glands leads to a loss of negative feedback on the pituitary, causing uncontrolled growth of a pre-existing **corticotroph adenoma** and increased **ACTH** production. *Hypophysectomy* - **Hypophysectomy** is the surgical removal of the **pituitary gland**, which would prevent the development of Nelson's syndrome as it removes the source of ACTH. - This procedure is a treatment for Cushing's disease, but Nelson's syndrome occurs *after* adrenalectomy, not hypophysectomy. *Thyroidectomy* - **Thyroidectomy** is the removal of all or part of the **thyroid gland** and is unrelated to adrenal or pituitary dysfunction. - This procedure is typically performed for conditions like thyroid cancer, hyperthyroidism, or large goiters. *Orchidectomy* - **Orchidectomy** is the surgical removal of one or both **testes**. - This procedure is primarily used in the treatment of testicular cancer or for hormonal therapy in prostate cancer and has no connection to Nelson's syndrome.

Q: Which of the following conditions is least likely to be associated with diabetes mellitus?

Fanconi syndrome. ***Fanconi syndrome*** - This syndrome primarily involves a generalized defect in **proximal renal tubular function**, leading to excessive excretion of glucose, amino acids, phosphate, and bicarbonate. - While it can be inherited or acquired, it is **not directly linked** to the pathogenesis or common complications of diabetes mellitus. *Noonan syndrome* - Individuals with Noonan syndrome are at an **increased risk of developing diabetes mellitus**, often due to insulin resistance and impaired glucose tolerance. - This genetic disorder, characterized by distinctive facial features, short stature, and cardiac defects, includes **endocrine abnormalities** that predispose to metabolic dysfunction. *Ataxia telangiectasia* - This rare, **autosomal recessive immune deficiency disorder** is associated with an increased incidence of diabetes mellitus [1]. - Patients often present with **insulin resistance** and impaired glucose homeostasis, making diabetes a recognized comorbidity [2]. *Myotonic dystrophy* - Myotonic dystrophy, particularly type 1, is frequently associated with **endocrine abnormalities**, including a high prevalence of **insulin resistance** and impaired glucose tolerance, often progressing to diabetes mellitus [2]. - This inherited neuromuscular disorder can manifest with a variety of systemic complications, with diabetes being a common one.

Q: For differentiating between insulinoma and sulfonylurea-related hypoglycemia, which test is most useful?

Plasma C-peptide level. Detailed testing is required to distinguish sources of hypoglycemia. Plasma C-peptide level: A high C-peptide level despite hypoglycemia suggests endogenous insulin secretion, as seen in insulinoma [1]. In sulfonylurea-induced hypoglycemia, a high C-peptide would also be seen because sulfonylureas stimulate endogenous insulin release from beta cells [2]. However, in an exogenous insulin injection, it would be low. Antibody to insulin: Antibody to insulin is primarily used to detect exogenous insulin administration due to an immune response. While it might be present in rare cases of autoimmune hypoglycemia, it is not the primary diagnostic tool to differentiate between these two conditions. Plasma insulin level: Both insulinoma and sulfonylurea use lead to elevated plasma insulin levels during hypoglycemia, as both involve increased insulin activity [1]. Therefore, insulin levels alone would not help distinguish between these two causes of hypoglycemia. Insulin:glucose ratio: The insulin:glucose ratio would be elevated in both insulinoma and sulfonylurea-induced hypoglycemia. This ratio indicates an inappropriately high level of insulin for the given glucose concentration, but it does not differentiate between endogenous overproduction and sulfonylurea stimulation.

Q: Which of the following statements about testicular feminizing syndrome is incorrect?

Absent vagina. ### Absent vagina - This statement is incorrect. In **complete androgen insensitivity syndrome (CAIS)**, formerly known as testicular feminizing syndrome, individuals develop a **blind-ending vagina** that is typically shorter than normal, but it is not entirely absent. - The external genitalia are unambiguously female, leading to a female appearance, but the presence of testes and lack of a uterus/fallopian tubes are key features. *Absent ovary* - This statement is correct. Individuals with **complete androgen insensitivity syndrome (CAIS)** are **genetically male (46,XY)** and have **testes**, not ovaries. - The testes are usually undescended (intra-abdominal or inguinal) and produce androgens, but the body's cells are unresponsive to these hormones. *Chromosome pattern 46 x Y* - This statement is correct. **Complete androgen insensitivity syndrome (CAIS)** is characterized by a **46,XY karyotype**, meaning individuals are genetically male [1]. - Despite the male genotype, the inability to respond to androgens leads to female external phenotypic development. *Absent uterus* - This statement is correct. In **complete androgen insensitivity syndrome (CAIS)**, the **testes produce anti-Müllerian hormone (AMH)**, which causes the regression of the Müllerian ducts. - As a result, structures derived from the Müllerian ducts, such as the **uterus** and fallopian tubes, are absent.

Question 1

A young patient presented with hypertension and a 24-hour urinary metanephrine level of 1.4 mg, the most likely causes are -

Accepted Answer

VonHippelLindau syndrome

Answer

Grave's disease

Answer

Pseudohypoparathyroidism

Answer

Medullary carcinoma thyroid

Question 2

Hot flushes are not associated with which of the following?

Accepted Answer

Radical prostatectomy

Answer

Medical castration

Answer

Surgical castration

Answer

Ketoconazole therapy

Question 3

Which of the following is the most prominent clinical manifestation of primary hyperaldosteronism (Conn's syndrome)?

Accepted Answer

Hypertension

Answer

Hyperkalemia

Answer

Hypokalemia

Answer

Expansion of Extracellular and Plasma volume

Question 4

What is the most common cause of hypercalcemia in outpatient settings?

Accepted Answer

Primary hyperparathyroidism

Answer

Malignancy

Answer

Vitamin D toxicity

Answer

Thiazide diuretics

Question 5

A 45-year-old woman presents with increased testosterone levels and temporal hair recession. What is the most likely diagnosis?

Accepted Answer

Polycystic Ovary Syndrome (PCOS)

Answer

Osteoporosis

Answer

Rheumatoid arthritis

Answer

Granulosa theca cell tumour

Question 6

Bones, stones, abdominal groans, and psychiatric overtones are features of?

Accepted Answer

Hyperparathyroidism

Answer

Hypothyroidism

Answer

Hypoparathyroidism

Answer

Hyperthyroidism

Question 7

Nelson's syndrome is most likely seen after removal of both adrenal glands.

Accepted Answer

Adrenalectomy

Answer

Hypophysectomy

Answer

Thyroidectomy

Answer

Orchidectomy

Question 8

Which of the following conditions is least likely to be associated with diabetes mellitus?

Accepted Answer

Fanconi syndrome

Answer

Noonan syndrome

Answer

Ataxia telengiectasia

Answer

Myotonic dystrophy

Question 9

For differentiating between insulinoma and sulfonylurea-related hypoglycemia, which test is most useful?

Accepted Answer

Plasma C-peptide level

Answer

Insulin:glucose ratio

Answer

Plasma insulin level

Answer

Antibody to insulin

Question 10

Which of the following statements about testicular feminizing syndrome is incorrect?

Accepted Answer

Absent vagina

Answer

Absent ovary

Answer

Chromosome pattern 46 x Y

Answer

Absent uterus

Endocrinology — MCQs

Endocrinology — MCQs

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