Endocrinology Practice Questions

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: 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: 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: 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: 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.

Q: Osteitis fibrosa cystica is associated with which of the following conditions?

Hyperparathyroidism. ***Hyperparathyroidism*** - **Osteitis fibrosa cystica** is a classic bone manifestation of severe, chronic **hyperparathyroidism**, characterized by increased osteoclastic activity. - This condition results in the replacement of normal bone with **fibrous tissue** and **cysts**, often leading to bone pain, fractures, and deformities. *Hypoparathyroidism* - **Hypoparathyroidism** is characterized by low parathyroid hormone (PTH) levels and **hypocalcemia**, which typically leads to increased bone density, not bone degradation. - Its manifestations include muscle cramps, seizures, and tetany, without the bone lesions seen in osteitis fibrosa cystica. *Hypothyroidism* - **Hypothyroidism** is a state of thyroid hormone deficiency, affecting metabolism and growth but not directly causing osteitis fibrosa cystica. - It can lead to slowed bone turnover and delayed growth in children, but not the specific bone lesions associated with parathyroid dysfunction. *Hyperthyroidism* - **Hyperthyroidism** can cause increased bone turnover and **osteoporosis** due to accelerated bone resorption, but it does not lead to the distinct fibrous and cystic bone changes of osteitis fibrosa cystica. - Its effects on bone are generally a diffuse reduction in bone mineral density rather than specific lytic lesions or brown tumors.

Q: A 32-year-old female who underwent whole-brain irradiation therapy following tumor growth in the brain is most likely to experience which hormone deficiency? (Select one correct answer)

Gonadotropin deficiency. A 32-year-old female who underwent whole-brain irradiation therapy following tumor growth in the brain is most likely to experience which hormone deficiency? ***Gonadotropin deficiency*** - The **gonadotrophs** (producing **LH and FSH**) are among the most sensitive pituitary cells to radiation damage, often leading to early and significant deficiency [1]. - This is particularly common after **whole-brain irradiation** due to the pituitary's location within the radiation field [1]. *Prolactin deficiency* - **Lactotrophs** (producing **prolactin**) are generally considered to be among the *most resistant* cells to radiation-induced damage. - **Prolactin deficiency** is rare even after high doses of radiation and is usually only seen with extensive pituitary damage. *ACTH deficiency* - **Corticotrophs** (producing **ACTH**) are moderately sensitive to radiation, but usually less so than gonadotrophs [1]. - While possible, **ACTH deficiency** typically develops later than gonadotropin deficiency or requires higher doses of radiation [1]. *Growth hormone deficiency* - **Somatotrophs** (producing **GH**) are often the second most sensitive cells to radiation damage after gonadotrophs [1]. - While common after cranial irradiation, **gonadotropin deficiency** typically manifests earlier or with lower doses than GH deficiency [1].

Q: The endocrine disorder associated with generalized lymphadenopathy is?

Hyperthyroidism. ***Hyperthyroidism*** - **Generalized lymphadenopathy** can be a clinical manifestation of **hyperthyroidism**, particularly in conditions like **Graves' disease** [1]. - This is thought to be due to **immunological overactivity** often associated with autoimmune thyroid conditions [2]. *Addison's disease* - **Addison's disease** is characterized by **adrenal insufficiency** and typically presents with symptoms like **fatigue**, **skin hyperpigmentation**, and **hypotension**. - It is not commonly associated with **generalized lymphadenopathy**. *Cushing's syndrome* - **Cushing's syndrome** results from **prolonged exposure to high levels of cortisol**, leading to symptoms like **central obesity**, **moon facies**, and **hirsutism**. - **Lymphadenopathy** is not a feature of **Cushing's syndrome**; in fact, chronic cortisol excess can cause **lymphopenia**. *Carcinoid syndrome* - **Carcinoid syndrome** is caused by **neuroendocrine tumors** secreting **vasoactive substances** like serotonin, leading to symptoms such as **flushing**, **diarrhea**, and **bronchospasm**. - **Lymphadenopathy** is not typically part of the carcinoid syndrome, although tumor metastasis to lymph nodes can occur.

Question 1

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 2

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 3

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

Accepted Answer

Adrenalectomy

Answer

Hypophysectomy

Answer

Thyroidectomy

Answer

Orchidectomy

Question 4

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 5

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

Accepted Answer

Hyperparathyroidism

Answer

Hypothyroidism

Answer

Hypoparathyroidism

Answer

Hyperthyroidism

Question 6

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 7

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

Question 8

Osteitis fibrosa cystica is associated with which of the following conditions?

Accepted Answer

Hyperparathyroidism

Answer

Hypoparathyroidism

Answer

Hypothyroidism

Answer

Hyperthyroidism

Question 9

A 32-year-old female who underwent whole-brain irradiation therapy following tumor growth in the brain is most likely to experience which hormone deficiency? (Select one correct answer)

Accepted Answer

Gonadotropin deficiency

Answer

Prolactin deficiency

Answer

ACTH deficiency

Answer

Growth hormone deficiency

Question 10

The endocrine disorder associated with generalized lymphadenopathy is?

Accepted Answer

Hyperthyroidism

Answer

Addison's disease

Answer

Carcinoid syndrome

Answer

Cushing's syndrome

Endocrinology — MCQs

Endocrinology — MCQs

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