Endocrinology Practice Questions

Q: These two brothers age 10 and 8 years are having short stature with midface hypoplasia, high squeaky voice. The levels of GH are elevated with normal TSH, FT4 and FT3. Diagnosis is?

Laron syndrome. ***Laron syndrome*** - This syndrome is characterized by **short stature**, a **high-pitched voice**, and **midface hypoplasia**, all consistent with the patient's presentation. - Patients with Laron syndrome have **elevated growth hormone (GH) levels** but cellular insensitivity to GH, leading to low IGF-1 levels. Their normal TSH, FT4, and FT3 exclude thyroid disorders. *Simmonds syndrome* - Simmonds syndrome refers to **panhypopituitarism** in adults, typically caused by a pituitary tumor or infarction. - It would present with **deficiencies in multiple pituitary hormones**, including GH, TSH, and ACTH, which is not consistent with elevated GH and normal thyroid hormones in children. *Hypothalamic dysgenesis* - **Hypothalamic dysgenesis** can lead to growth hormone deficiency if the hypothalamus is unable to produce sufficient growth hormone-releasing hormone (GHRH). - This would result in **low GH levels**, not elevated GH as seen in the patient. *Thyroid dysgenesis* - **Thyroid dysgenesis** results in congenital hypothyroidism, characterized by **elevated TSH** and **low FT4/FT3**. - The patient has normal TSH, FT4, and FT3 levels, ruling out primary thyroid dysfunction.

Q: The following child with Genu Valgum has been treated with multiple dosages of injectable vitamin D3 supplements at a P.H.C. The lab values ordered by you shows serum calcium = 9 mg% with low serum phosphate and normal levels of 25-hydroxycholecalciferol. The most probable defect is?

Defect in PHEX gene. ***Defect in PHEX gene*** - The combination of **Genu Valgum** (a sign of rickets/osteomalacia), low serum phosphate, normal calcium, and normal 25-hydroxycholecalciferol levels despite high-dose vitamin D3 supplementation is characteristic of **X-linked hypophosphatemic rickets (XLH)**. - XLH is caused by a **defect in the PHEX gene**, leading to increased levels of **FGF23**, which causes renal phosphate wasting and impaired 1,25-dihydroxyvitamin D production. *Chronic renal failure* - **Chronic renal failure** would typically present with **elevated phosphate** and low calcium due to impaired phosphate excretion and decreased calcitriol production. - The patient has **low serum phosphate**, which contradicts the typical electrolyte imbalance seen in chronic renal failure. *Hypoparathyroidism* - **Hypoparathyroidism** is characterized by **low calcium** and **high phosphate** due to insufficient parathyroid hormone (PTH) activity. - This patient has normal calcium and low phosphate, which is inconsistent with hypoparathyroidism. *Pseudohypoparathyroidism* - **Pseudohypoparathyroidism** involves **target organ resistance to PTH**, leading to **hypocalcemia** and **hyperphosphatemia**, as seen in hypoparathyroidism, but with elevated PTH levels. - The patient's normal calcium and low phosphate levels do not align with the biochemical profile of **pseudohypoparathyroidism**.

Q: What is the most likely diagnosis based on the clinical presentation and MRI findings shown?

Hypothalamic hamartoma. ***Hypothalamic hamartoma*** - The image shows a young girl with signs of **precocious puberty** (breast development), and the MRI scan reveals a lesion (indicated by the arrow) consistent with a **hypothalamic hamartoma**. - **Hypothalamic hamartomas** are non-cancerous growths that can secrete **gonadotropin-releasing hormone (GnRH)**, leading to central precocious puberty. *Simmond's disease* - Simmond's disease refers to **panhypopituitarism**, characterized by an extreme deficiency of all pituitary hormones. - This typically results in **hypogonadism** and **failure of secondary sexual characteristics** to develop, which is the opposite of what is seen in the image. *Non-functioning pituitary tumor* - A non-functioning pituitary tumor does **not secrete hormones** and would not cause precocious puberty. - These tumors often present with symptoms related to **mass effect**, such as headaches or visual field defects. *McCune-Albright syndrome* - McCune-Albright syndrome is characterized by a triad of **precocious puberty**, **café-au-lait spots**, and **fibrous dysplasia of bone**. - While it causes precocious puberty, the image does not provide evidence of café-au-lait spots or fibrous dysplasia, and an MRI showing a distinct hypothalamic lesion points away from this diagnosis.

Q: In this case of ambiguous genitalia, all of the following investigations are needed EXCEPT:

24 -hour urinary chloride. ***24-hour urinary chloride*** - The image shows **ambiguous genitalia**, which is highly suggestive of **congenital adrenal hyperplasia (CAH)** due to 21-hydroxylase deficiency. - CAH in girls often presents with **salt-wasting crises**; mineralocorticoid deficiency in salt-wasting CAH causes **inappropriate urinary sodium and chloride loss**, so 24-hour urinary chloride would not be needed for diagnosis. *Pelvic ultrasonography* - **Pelvic ultrasound** is a routinely necessary initial investigation in cases of ambiguous genitalia to identify the presence of a uterus, ovaries, or other internal structures, helping to determine the underlying etiology. - This assessment is fundamental for accurate diagnosis and gender assignment. *Karyotype* - A **karyotype** is essential to determine the **genetic sex** in cases of ambiguous genitalia, differentiating between **46,XX CAH** and other conditions like **androgen insensitivity syndrome** (46,XY). - This test is fundamental for accurate diagnosis and gender assignment. *Serum electrolytes* - Infants with **classic CAH** due to 21-hydroxylase deficiency are at high risk for **salt-wasting crises**, which involve abnormalities in **serum sodium, potassium, and glucose**. - Monitoring serum electrolytes is vital for detecting and managing these life-threatening crises.

Q: A 10-year-old short stature child presents with daily headache, vomiting, increased urine output and polydipsia. CT head is performed. All are true about the condition except:

Best managed with CNS radiation and chemotherapy. ***Best managed with CNS radiation and chemotherapy*** - **Craniopharyngiomas** are benign tumors and aggressive management with **radiation** and **chemotherapy** is generally avoided due to significant risk of neurocognitive and endocrine side effects, especially in young children. - The primary treatment is **surgical resection**, which can be followed by adjuvant radiotherapy if there is residual tumor and high risk of recurrence. *Most common type is Adamantinomatous variant* - The **adamantinomatous craniopharyngioma** is the most common histological subtype, particularly in children. - It often presents with characteristic **cystic and solid components** and calcifications on imaging. *Supratentorial lesion with both solid and cystic presentation* - **Craniopharyngiomas** are typically **suprasellar tumors**, meaning they are located in the supratentorial region near the sella turcica. - They commonly exhibit both **solid and cystic components** on imaging, often with calcifications. *Leads to Pan-hypopituitarism* - Due to their location near the **pituitary gland** and **hypothalamus**, craniopharyngiomas frequently compress these structures. - This compression can lead to various **endocrine deficiencies**, including growth hormone deficiency (causing short stature), diabetes insipidus (increased urine output and polydipsia), and other hypopituitary states.

Q: A neonate presents with the clinical features shown in the image below. The infant also has prolonged jaundice, constipation, and a hoarse cry. Thyroid function tests reveal an elevated TSH and low free T4. What is the most likely diagnosis?

Congenital hypothyroidism. ***Congenital hypothyroidism*** - The image shows a neonate with **macroglossia** (large tongue), **umbilical hernia**, and possibly **puffy eyelids** and **dull facies**, all characteristic signs of congenital hypothyroidism. - Other features often include **hypotonia**, **feeding difficulties**, **prolonged jaundice**, and **constipation**. *Down syndrome* - While Down syndrome can present with **hypotonia** and some shared features, the characteristic **epicanthal folds**, **simian crease**, **brushfield spots**, and flattened facial profile are not clearly evident. - Macroglossia is common but other features like an umbilical hernia would be less specific. *Ellis-Van Creveld syndrome* - This syndrome is characterized by **chondroectodermal dysplasia**, typically presenting with **polydactyly**, **short-limbed dwarfism**, **nail dysplasia**, and **cardiac defects**. - These distinct skeletal and ectodermal abnormalities are not visible in the presented image. *Turner syndrome* - Turner syndrome (XO karyotype) primarily affects females and is characterized by **short stature**, **webbed neck**, **lymphedema of hands and feet**, and **cardiac anomalies** (e.g., coarctation of the aorta). - The features shown in the image, such as macroglossia and umbilical hernia, are not typical of Turner syndrome.

Q: A 5-year-old girl is referred for vaginal bleeding. Physical examination shows breast development, multiple cystic changes in bone radiologically and following skin finding. What is the most likely pubertal disorder?

Peripheral precocious puberty. ***Peripheral precocious puberty*** - The combination of **vaginal bleeding**, **breast development**, **multiple cystic changes in bone** (fibrous dysplasia), and the characteristic **café-au-lait spots with irregular borders** (as seen in the image) is highly suggestive of **McCune-Albright syndrome**. - McCune-Albright syndrome is a classic cause of **peripheral precocious puberty**, not due to premature activation of the hypothalamic-pituitary-gonadal (HPG) axis, but rather autonomous production of sex hormones (e.g., estrogen) from an ovarian cyst or other endocrine tissues. *Premature thelarche* - This condition involves isolated **breast development** without other signs of puberty or bone age advancement. - It does not typically present with vaginal bleeding, bone lesions, or café-au-lait spots. *Central precocious puberty* - This involves true activation of the **hypothalamic-pituitary-gonadal (HPG) axis**, leading to pulsatile GnRH secretion and elevated FSH/LH levels. - While it causes breast development and vaginal bleeding, it does not explain the multiple cystic bone changes or the characteristic café-au-lait spots. *Normal, no pubertal disorder* - Vaginal bleeding and breast development at 5 years of age are **abnormal** and indicate a pubertal disorder. - The presence of associated bone lesions and specific skin findings further rules out a normal developmental process.

Question 1

These two brothers age 10 and 8 years are having short stature with midface hypoplasia, high squeaky voice. The levels of GH are elevated with normal TSH, FT4 and FT3. Diagnosis is?

Accepted Answer

Laron syndrome

Answer

Simmonds syndrome

Answer

Hypothalamic dysgenesis

Answer

Thyroid dysgenesis

Question 2

A child presents with the appearance shown in the image. On examination, the child has bradycardia, hypotonia, constipation, and delayed developmental milestones. Thyroid function tests reveal an elevated TSH and low free T4. The child most likely suffers from?

Accepted Answer

Hypothyroidism

Answer

Adrenal tumor

Answer

Pan-hypopituitarism

Answer

Non-functioning pituitary tumor

Question 3

The following child with Genu Valgum has been treated with multiple dosages of injectable vitamin D3 supplements at a P.H.C. The lab values ordered by you shows serum calcium = 9 mg% with low serum phosphate and normal levels of 25-hydroxycholecalciferol. The most probable defect is?

Accepted Answer

Defect in PHEX gene

Answer

Chronic renal failure

Answer

Hypoparathyroidism

Answer

Pseudohypoparathyroidism

Question 4

What is the most likely diagnosis based on the clinical presentation and MRI findings shown?

Accepted Answer

Hypothalamic hamartoma

Answer

Simmond's disease

Answer

Non-functioning pituitary tumor

Answer

McCune-Albright syndrome

Question 5

In this case of ambiguous genitalia, all of the following investigations are needed EXCEPT:

Accepted Answer

24 -hour urinary chloride

Answer

Serum electrolytes

Answer

Karyotype

Answer

Pelvic ultrasonography

Question 6

A 10-year-old short stature child presents with daily headache, vomiting, increased urine output and polydipsia. CT head is performed. All are true about the condition except:

Accepted Answer

Best managed with CNS radiation and chemotherapy

Answer

Most common type is Adamantinomatous variant

Answer

Supratentorial lesion with both solid and cystic presentation

Answer

Leads to Pan-hypopituitarism

Question 7

A newborn girl presents with ambiguous genitalia. Investigations reveal markedly elevated 17-hydroxyprogesterone, hyponatremia, and hyperkalemia, consistent with classic salt-wasting 21-hydroxylase deficiency. All are seen in this girl child except:

Accepted Answer

Girl children are more likely to die than boys

Answer

Metabolic acidosis

Answer

Hyponatremia and hyperkalemia

Answer

Urinary 17-ketosteroid excretion is markedly elevated

Question 8

A neonate presents with the clinical features shown in the image below. The infant also has prolonged jaundice, constipation, and a hoarse cry. Thyroid function tests reveal an elevated TSH and low free T4. What is the most likely diagnosis?

Accepted Answer

Congenital hypothyroidism

Answer

Down syndrome

Answer

Turner syndrome

Answer

Ellis-Van Creveld syndrome

Question 9

Comment on the diagnosis of the child:

Accepted Answer

Congenital hypothyroidism

Answer

Beckwith-Wiedemann syndrome

Answer

Down syndrome

Answer

Hurler syndrome

Question 10

A 5-year-old girl is referred for vaginal bleeding. Physical examination shows breast development, multiple cystic changes in bone radiologically and following skin finding. What is the most likely pubertal disorder?

Accepted Answer

Peripheral precocious puberty

Answer

Premature thelarche

Answer

Central precocious puberty

Answer

Normal, no pubertal disorder

Endocrinology — MCQs

Endocrinology — MCQs

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