Endocrinology Practice Questions

Q: An XX baby presenting with male genitalia (penis and scrotum) is likely due to which of the following conditions?

High level of testosterone in maternal blood. ***High level of testosterone in maternal blood*** - An **XX baby** (genetically female) presenting with **fully masculinized external genitalia** (penis and scrotum) indicates significant **androgen exposure** during the critical period of sexual differentiation (8-12 weeks of gestation). - While the most common cause is **congenital adrenal hyperplasia (CAH)** due to fetal androgen excess, **maternal sources of androgens** can also cause complete masculinization. - Maternal causes include **virilizing tumors** (e.g., luteoma of pregnancy, Krukenberg tumor, arrhenoblastoma), **exogenous androgen administration**, or **maternal CAH**. - High sustained maternal testosterone crosses the placenta and causes **virilization of female fetus**, which can range from clitoromegaly to complete male phenotype. - This is the **only medically correct option** among the choices given, though CAH (not listed) would be the most common cause overall. *Klinefelter syndrome* - **47, XXY karyotype** - genetically male due to presence of Y chromosome with SRY gene. - Presents as phenotypic male, not relevant to an **XX individual**. - Features include hypogonadism, infertility, tall stature, and gynecomastia. *Turner syndrome* - **45, X karyotype** - monosomy X, genetically and phenotypically female. - Presents with **female external genitalia**, streak gonads, short stature, webbed neck. - Cannot explain masculinized genitalia in any scenario. *None of the options* - This is incorrect because **high level of testosterone in maternal blood** is a documented cause of XX virilization with male phenotype, though less common than fetal CAH.

Q: A 5-year-old boy presents with pubic hair development, being tall, and having increased pigmentation of his genitalia and phallic enlargement, along with a blood pressure of 130/90 mmHg. Measurement of which of the following diagnostic hormones would be most likely to indicate a diagnosis of congenital adrenal hyperplasia?

Increase 17-hydroxyprogesterone. ***Increase 17 beta-hydroxyprogesterone*** - The clinical presentation of **precocious puberty** (pubic hair, phallic enlargement), **hypertension**, and **hyperpigmentation** strongly suggests **congenital adrenal hyperplasia (CAH)**. - In most common forms of CAH (e.g., 21-hydroxylase deficiency), there is an inability to convert **17-hydroxyprogesterone** to 11-deoxycortisol, leading to its significant accumulation. *Increase cortisol* - In CAH due to enzyme deficiencies, the adrenal glands are unable to synthesize sufficient **cortisol**, leading to its **decrease**, not an increase. - The low cortisol then triggers increased **ACTH** release, driving the overproduction of adrenal androgens and precursors. *Increase aldosterone* - Only in specific forms of CAH (e.g., 17-alpha-hydroxylase deficiency) would **aldosterone** be increased (due to shunting of precursors), but this is less common and would typically present with hypokalemia rather than hyperpigmentation. - In the more common 21-hydroxylase deficiency, **aldosterone can be decreased** (salt-wasting form), or normal, leading to hyponatremia and hyperkalemia. *Increase 11-deoxycortisol* - An increase in **11-deoxycortisol** is characteristic of **11-beta-hydroxylase deficiency**, another form of CAH. - While this form also causes **hypertension** and **virilization**, the most prominent precursor elevated in the majority of CAH cases (21-hydroxylase deficiency) is **17-hydroxyprogesterone**.

Q: A 7-day-old newborn presents with vomiting and dehydration. The clinical examination is normal except for hyperpigmentation of the nipple. Electrolyte levels show Na: 120 meq/L and K: 9 meq/L. What is the most likely diagnosis?

Congenital adrenal hyperplasia. ***Congenital adrenal hyperplasia*** - In **congenital adrenal hyperplasia (CAH)**, particularly 21-hydroxylase deficiency, mineralocorticoid deficiency leads to **salt wasting** with **hyponatremia** and **hyperkalemia**, as seen in this newborn. - **Hyperpigmentation** occurs due to increased ACTH, which also stimulates melanocytes, as a result of cortisol deficiency. *Primary hypothyroidism* - While newborns with primary hypothyroidism can present with feeding difficulties and lethargy, **electrolyte abnormalities** like severe hyponatremia and hyperkalemia are not typical features. - **Hyperpigmentation** is also not a common finding in primary hypothyroidism. *Panhypopituitarism* - **Panhypopituitarism** in a newborn can cause hypoglycemia and other hormone deficiencies, but generally does not present with isolated and severe **salt-wasting crisis** with hyperkalemia, nor isolated nipple hyperpigmentation in this manner. - Multiple trophic hormone deficiencies would be expected, rather than primarily adrenal crisis symptoms. *Pyloric stenosis* - **Pyloric stenosis** typically presents with **non-bilious projectile vomiting** starting around 3-6 weeks of age, not commonly at 7 days, and leads to **hypochloremic alkalosis** with hypokalemia, not hyperkalemia and hyponatremia. - **Hyperpigmentation** is not associated with pyloric stenosis.

Q: All of the following statements about Nesidioblastosis are true, except:

Occurs in adults more than children. ***Occurs in adults more than children*** - **Nesidioblastosis** is a rare condition predominantly seen in **infants and children**, especially those with congenital hyperinsulinism. It is far less common in adults. - While adult forms can occur, the statement that it occurs more in adults than children is incorrect. *Hypoglycemic episodes may be seen* - Nesidioblastosis is characterized by **unregulated or excessive insulin secretion**, leading to recurrent episodes of severe **hypoglycemia**. - These hypoglycemic episodes can cause significant morbidity, particularly in infants. *Histopathology shows hyperplasia of islet cells* - The defining feature of nesidioblastosis is the **diffuse or focal hyperplasia of pancreatic islet cells**, particularly the beta cells. - These hyperplastic cells may be found budding off ducts or dispersed throughout the exocrine pancreas. *Diazoxide may be used for treatment* - **Diazoxide** is an ATP-sensitive potassium channel opener that reduces insulin secretion from pancreatic beta cells. - It is a common medical therapy used to manage hypoglycemia in patients with nesidioblastosis, especially in pediatric cases where it can sometimes avoid the need for surgery.

Q: What is the most common cause of primary adrenal insufficiency in children?

Congenital adrenal hyperplasia. ***Congenital adrenal hyperplasia*** - **Congenital adrenal hyperplasia (CAH)** is a group of genetic disorders that affect the adrenal glands' ability to produce hormones. - It is the most common cause of **primary adrenal insufficiency** in children, particularly in newborns and infants, due to enzymatic defects like **21-hydroxylase deficiency**. *Autoimmune adrenalitis* - While it is the most common cause of primary adrenal insufficiency (Addison's disease) in adults, **autoimmune adrenalitis** is far less common in children. - Its incidence increases with age, primarily manifesting in **adolescents and adults**. *Adrenal hemorrhage* - **Adrenal hemorrhage** can cause acute adrenal crisis, especially in neonates due to birth trauma or stress, but it is not a common cause of chronic **primary adrenal insufficiency**. - It is typically an acute event rather than a long-term cause of adrenal dysfunction. *None of the options* - This option is incorrect because **Congenital Adrenal Hyperplasia** is a well-established and frequent cause of primary adrenal insufficiency in children.

Q: Which of the following is NOT a feature of hypothyroidism?

Short metacarpals in hands. Short metacarpals in hands - While other skeletal developmental issues like **delayed bone age** and altered proportions are seen in hypothyroidism, **short metacarpals** (brachydactyly) are not a typical feature. - Short metacarpals are more characteristic of conditions like **Turner syndrome** or **pseudohypoparathyroidism**, not primary hypothyroidism. *Delayed puberty* - **Hypothyroidism** can lead to significant delays in growth and development, including **delayed onset of puberty**, due to its impact on overall metabolic processes and hormonal regulation [1]. - Insufficient thyroid hormones are crucial for proper **gonadal development** and function. *Delayed bone age* - **Thyroid hormones** are essential for normal epiphyseal fusion and bone maturation; therefore, their deficiency in hypothyroidism leads to a **delayed skeletal maturation**, which is observed as a delayed bone age on X-rays [1]. - This delay indicates that the bones are less mature than expected for the chronological age of the individual. *Altered upper and lower segment ratio* - In children with **untreated hypothyroidism**, bone growth can be disproportionate, leading to an **altered upper to lower segment ratio**. - Specifically, they may have relatively **shortened legs** (lower segment) compared to their trunk (upper segment).

Q: A boy presented with prolonged jaundice, constipation, and umbilical hernia. What is the probable diagnosis?

Congenital hypothyroidism. ***Congenital hypothyroidism*** - **Prolonged jaundice** is a common and early sign in congenital hypothyroidism due to delayed bilirubin conjugation and excretion. - **Constipation** and an **umbilical hernia** are classic features, reflecting decreased gut motility and weak abdominal muscles associated with thyroid hormone deficiency. *Growth hormone deficiency* - Primarily presents with **short stature** and delayed bone age, not typically with prolonged jaundice or umbilical hernia in infancy. - While it can be associated with some developmental delays, the combination of signs in the question points away from this diagnosis. *Kernicterus* - This is a neurological consequence of **untreated severe hyperbilirubinemia**, leading to brain damage, not a primary cause of jaundice itself. - While prolonged jaundice is present, kernicterus would manifest with severe neurological symptoms like lethargy, poor feeding, and opisthotonus, not umbilical hernia. *Congenital adrenal hyperplasia* - Presents due to deficiencies in adrenal steroid synthesis, leading to **ambiguous genitalia** in females and **salt-wasting crises** in classic forms. - It does not typically cause prolonged jaundice or umbilical hernia as primary manifestations.

Q: An infant who is crying excessively despite being well-fed, passes a large quantity of urine, and repeatedly becomes dehydrated is most likely to have –

Diabetes insipidus (DI). ***Diabetes insipidus (DI)*** - The symptoms of **excessive crying**, **polyuria**, and **recurrent dehydration** in a well-fed infant are classic presentations of diabetes insipidus. - DI is characterized by the body's inability to concentrate urine due to insufficient production of **antidiuretic hormone (central DI)** or renal unresponsiveness to ADH (**nephrogenic DI**). *Diabetes mellitus (DM)* - While DM also causes **polyuria** and **dehydration**, it would typically present with **polydipsia** (excessive thirst which is difficult to assess in an infant), and often **poor feeding** or weight loss, not excessive crying despite being well-fed. - Laboratory findings would show **hyperglycemia** and **glycosuria**, which are not implied by the provided symptoms. *Congenital nephrotic syndrome (CNS)* - CNS is characterized by significant **proteinuria**, **edema**, and **hypoalbuminemia**, leading to poor growth and increased susceptibility to infections. - It does not typically cause **polyuria** leading to rapid dehydration in the same manner as DI. *Protein losing enteropathy (PLE)* - PLE involves excessive loss of **plasma proteins** into the gastrointestinal tract, leading to **edema**, **hypoalbuminemia**, and sometimes **diarrhea** or malabsorption. - It does not directly cause significant **polyuria** or a primary picture of dehydration in the way described.

Q: Treatment of choice in childhood thyrotoxicosis is:

Carbimazole. ***Carbimazole*** - **Antithyroid medications** like carbimazole are the **first-line treatment** for childhood thyrotoxicosis due to their efficacy in controlling hormone levels and lower risk compared to other interventions. - It works by inhibiting the synthesis of **thyroid hormones**, allowing for a gradual resolution of symptoms. *Radioiodine therapy* - This treatment is generally avoided in children due to potential long-term risks, including an increased risk of **thyroid cancer** and the need for lifelong **thyroid hormone replacement**. - It is typically reserved for older adolescents or cases where other treatments have failed. *Surgical intervention* - **Thyroidectomy** is usually considered a last resort in children due to the risks associated with surgery, such as damage to the **parathyroid glands** or **recurrent laryngeal nerve**. - It may be indicated in cases of very large goiter, drug intolerance, or non-compliance with medical therapy. *Lugol's iodine solution* - **Lugol's iodine** is primarily used for **short-term preparation** before thyroid surgery to decrease the vascularity of the gland and in **thyroid storm** to block hormone release. - It is not a definitive long-term treatment for childhood thyrotoxicosis due to its transient effect and potential for rebound hyperthyroidism.

Q: Which of the following conditions is least likely to present with ambiguous genitalia?

Super female (47 XXX). ***Super female (47 XXX)*** - Individuals with **47,XXX syndrome**, often called "triple X syndrome," typically have a **normal female phenotype** and are not usually born with ambiguous genitalia. - While they may have some developmental differences or fertility issues, their external genitalia are typically **unambiguously female**. *Gonadal dysgenesis* - This condition involves **abnormal development of the gonads**, leading to a spectrum of presentations that can include **ambiguous genitalia**. - Incomplete differentiation of the testes or ovaries can result in external genitalia that are neither definitively male nor female. *Hermaphroditism* - **True hermaphroditism** (now referred to as **ovotesticular disorder of sex development**) is characterized by the presence of **both ovarian and testicular tissue** in the same individual. - This condition almost always results in **ambiguous external genitalia** because the sex hormone production is mixed. *Gonadal agenesis* - **Gonadal agenesis** refers to the **complete absence of gonads**, which can lead to ambiguous genitalia, particularly if gonadal development failed before external genitalia differentiation. - Without the hormones produced by the gonads (e.g., androgens from testes), the development of male external genitalia is impaired, leading to **under-masculinization** or ambiguous features.

Question 1

An XX baby presenting with male genitalia (penis and scrotum) is likely due to which of the following conditions?

Accepted Answer

High level of testosterone in maternal blood

Answer

Turner syndrome

Answer

None of the options

Answer

Klinefelter syndrome

Question 2

A 5-year-old boy presents with pubic hair development, being tall, and having increased pigmentation of his genitalia and phallic enlargement, along with a blood pressure of 130/90 mmHg. Measurement of which of the following diagnostic hormones would be most likely to indicate a diagnosis of congenital adrenal hyperplasia?

Accepted Answer

Increase 17-hydroxyprogesterone

Answer

Increase cortisol

Answer

Increase aldosterone

Answer

Increase 11 deoxycortisol

Question 3

A 7-day-old newborn presents with vomiting and dehydration. The clinical examination is normal except for hyperpigmentation of the nipple. Electrolyte levels show Na: 120 meq/L and K: 9 meq/L. What is the most likely diagnosis?

Accepted Answer

Congenital adrenal hyperplasia

Answer

Primary hypothyroidism

Answer

Panhypopituitarism

Answer

Pyloric stenosis

Question 4

All of the following statements about Nesidioblastosis are true, except:

Accepted Answer

Occurs in adults more than children

Answer

Histopathology shows hyperplasia of islet cells

Answer

Hypoglycemic episodes may be seen

Answer

Diazoxide may be used for treatment

Question 5

What is the most common cause of primary adrenal insufficiency in children?

Accepted Answer

Congenital adrenal hyperplasia

Answer

Autoimmune adrenalitis

Answer

Adrenal hemorrhage

Answer

None of the options

Question 6

Which of the following is NOT a feature of hypothyroidism?

Accepted Answer

Short metacarpals in hands

Answer

Delayed puberty

Answer

Delayed bone age

Answer

Altered upper and lower segment ratio

Question 7

A boy presented with prolonged jaundice, constipation, and umbilical hernia. What is the probable diagnosis?

Accepted Answer

Congenital hypothyroidism

Answer

Growth hormone deficiency

Answer

Kernicterus

Answer

Congenital adrenal hyperplasia

Question 8

An infant who is crying excessively despite being well-fed, passes a large quantity of urine, and repeatedly becomes dehydrated is most likely to have –

Accepted Answer

Diabetes insipidus (DI)

Answer

Diabetes mellitus (DM)

Answer

Congenital nephrotic syndrome (CNS)

Answer

Protein losing enteropathy (PLE)

Question 9

Treatment of choice in childhood thyrotoxicosis is:

Accepted Answer

Carbimazole

Answer

Radioiodine therapy

Answer

Surgical intervention

Answer

Lugol's iodine solution

Question 10

Which of the following conditions is least likely to present with ambiguous genitalia?

Accepted Answer

Super female (47 XXX)

Answer

Hermaphroditism

Answer

Gonadal dysgenesis

Answer

Gonadal agenesis

Endocrinology — MCQs

Endocrinology — MCQs

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