Endocrine

Question 1

1. A 10-year-old boy presents with weight loss, polyuria, polydipsia, and nocturnal enuresis for the past 2 weeks. His blood glucose is 320 mg/dL, and his HbA1c is 9.1%. Which of the following is the best next step in management?
   A. Start Metformin
   B. Lifestyle modification and repeat glucose test in 3 months
   C. Start insulin therapy
   D. Order an oral glucose tolerance test

Answer 1

C. Start insulin therapy (Classic presentation of Type 1 DM; insulin is required)

Question 2

2. A 15-year-old obese girl presents for a routine checkup. She has dark, velvety patches on her neck. Her fasting glucose is 140 mg/dL, and her HbA1c is 7.2%. What is the most likely diagnosis?
   A. Type 1 DM
   B. Type 2 DM
   C. Cushing’s syndrome
   D. Pheochromocytoma

Answer 2

B. Type 2 DM (Acanthosis nigricans + obesity + hyperglycemia suggest insulin resistance)

Question 3

3. Which of the following is NOT a risk factor for Type 1 Diabetes Mellitus?
   A. HLA-DR3 and HLA-DR4
   B. Early introduction of cow’s milk
   C. Obesity
   D. Viral infections

Answer 3

C. Obesity (Obesity is a risk factor for Type 2 DM, not Type 1)

Question 4

4. What is the first-line treatment for newly diagnosed Type 2 Diabetes in children?
   A. Sulfonylureas
   B. Insulin
   C. Metformin
   D. DPP-4 inhibitors

Answer 4

C. Metformin (1st line for T2DM if no severe symptoms)

Question 5

5. A 12-year-old boy with Type 1 DM presents with vomiting, abdominal pain, deep rapid breathing, and confusion. His blood glucose is 450 mg/dL, pH is 7.1, and bicarbonate is 9 mEq/L. What is the best initial management?
   A. IV Insulin bolus followed by infusion
   B. IV Fluids
   C. Sodium bicarbonate administration
   D. Subcutaneous Insulin

Answer 5

B. IV Fluids (First step in DKA is fluid resuscitation)

Question 6

6. What is the most feared complication of DKA treatment?
   A. Acute kidney injury
   B. Hypoglycemia
   C. Cerebral edema
   D. Hyperkalemia

Answer 6

C. Cerebral edema (⚠ Risk increases with rapid fluid shifts)

Question 7

7. A 2-week-old newborn is diagnosed with congenital hypothyroidism via newborn screening. What is the most appropriate next step in management?
   A. Start levothyroxine immediately
   B. Repeat TSH in 2 weeks
   C. Wait until 1 month of age to confirm diagnosis
   D. Dietary iodine supplementation

Answer 7

A. Start levothyroxine immediately (Delays can cause intellectual disability)

Question 8

8. A 14-year-old girl presents with weight loss, palpitations, anxiety, and difficulty sleeping. On examination, she has a diffusely enlarged goiter and exophthalmos. What is the most likely diagnosis?
   A. Hashimoto thyroiditis
   B. Graves’ disease
   C. Thyroid adenoma
   D. Toxic multinodular goiter

Answer 8

B. Graves’ disease (Exophthalmos = only in Graves)

Question 9

9. Which of the following lab findings is most suggestive of Hashimoto’s thyroiditis?
   A. ↑ TSH, ↑ Free T4
   B. ↓ TSH, ↑ Free T4
   C. ↑ TSH, ↓ Free T4
   D. Normal TSH, ↑ Free T4

Answer 9

C. ↑ TSH, ↓ Free T4 (Primary hypothyroidism pattern)

Question 10

10. A 2-year-old child presents with bowing of the legs, frontal bossing, and widening of the wrists. Lab results show ↓ calcium, ↓ phosphorus, and ↑ ALP. What is the most likely diagnosis?
    A. Osteogenesis Imperfecta
    B. Nutritional Rickets
    C. Hypophosphatasia
    D. Vitamin C deficiency

Answer 10

B. Nutritional Rickets (Classic signs + ↓ Vit D)

Question 11

11. What is the most common genetic cause of brittle bones and blue sclera in children?
    A. Marfan Syndrome
    B. Osteogenesis Imperfecta
    C. Ehlers-Danlos Syndrome
    D. Rickets

Answer 11

B. Osteogenesis Imperfecta (Due to COL1A1/2 mutation)

Question 12

12. A 6-year-old boy presents with excessive thirst and polyuria. He prefers drinking ice-cold water. His serum sodium is 150 mEq/L, urine osmolality is low, and urine output remains high even after water deprivation. Which of the following is the most likely diagnosis?
    A. Nephrogenic diabetes insipidus
    B. Central diabetes insipidus
    C. Psychogenic polydipsia
    D. SIADH

Answer 12

B. Central DI (Water deprivation test does not concentrate urine)

Question 13

13. A 5-year-old boy with a history of lithium use presents with polyuria and hypernatremia. Water deprivation test shows no response to desmopressin. What is the likely diagnosis?
    A. SIADH
    B. Central DI
    C. Nephrogenic DI
    D. Psychogenic polydipsia

Answer 13

C. Nephrogenic DI (Resistant to desmopressin)

Question 14

14. What is the best initial treatment for Central DI?
    A. Thiazide diuretics
    B. Desmopressin
    C. Fluid restriction
    D. NSAIDs

Answer 14

B. Desmopressin (Synthetic ADH replacement)

Question 15

1. A 10-year-old boy is brought to the clinic for poor growth. His parents are concerned as he is significantly shorter than his classmates. His bone age is delayed, and he has normal body proportions. What is the most likely endocrine cause of his short stature?
   A. Familial short stature
   B. Growth hormone deficiency
   C. Achondroplasia
   D. Malnutrition

Answer 15

B. Growth hormone deficiency
📌 Rationale: GH deficiency leads to proportionate short stature with delayed bone age. Malnutrition is a common cause but would show systemic signs of poor nutrition. Familial short stature has normal growth velocity and bone age. Achondroplasia causes disproportionate short stature.

Question 16

2. Which of the following glands does NOT require a releasing hormone from the hypothalamus to function?
   A. Thyroid
   B. Adrenal cortex
   C. Pancreas
   D. Gonads

Answer 16

C. Pancreas
📌 Rationale: Unlike other endocrine glands, the pancreas does not require a hypothalamic releasing hormone to regulate its function. It releases insulin and glucagon independently based on blood glucose levels.

Question 17

3. A 7-year-old boy with delayed puberty is found to have a deficiency of Gonadotropin-Releasing Hormone (GnRH). Which hormone is most directly affected?
   A. Growth hormone
   B. Thyroid-stimulating hormone
   C. Luteinizing hormone
   D. Adrenocorticotropic hormone

Answer 17

C. Luteinizing hormone (LH)
📌 Rationale: GnRH from the hypothalamus stimulates the pituitary to release LH and FSH, which are responsible for sexual development. GH is stimulated by GHRH, TSH by TRH, and ACTH by CRH.

Question 18

4. A neonate with ambiguous genitalia and hyperpigmentation is found to have Congenital Adrenal Hyperplasia (CAH). Which hypothalamic hormone is excessively produced in response to the lack of adrenal hormones?
   A. Thyrotropin-releasing hormone (TRH)
   B. Corticotropin-releasing hormone (CRH)
   C. Growth hormone-releasing hormone (GHRH)
   D. Dopamine

Answer 18

B. Corticotropin-releasing hormone (CRH)
📌 Rationale: In CAH, adrenal cortisol and aldosterone are deficient, leading to excess CRH secretion to stimulate the pituitary to release ACTH. This increases androgen production, leading to ambiguous genitalia in females and early puberty in males.

Question 19

5. Which of the following hormones is stored in the posterior pituitary gland but synthesized in the hypothalamus?
   A. Growth hormone
   B. Prolactin
   C. Oxytocin
   D. Thyroid-stimulating hormone

Answer 19

C. Oxytocin
📌 Rationale: The posterior pituitary stores oxytocin and antidiuretic hormone (ADH), but both are synthesized in the hypothalamus. GH, TSH, and prolactin are secreted directly from the anterior pituitary.

Question 20

6. A 9-year-old girl presents with excessive thirst and frequent urination. Laboratory tests reveal high plasma osmolality and low urine osmolality. Which hormone is most likely deficient?
   A. Growth hormone
   B. Antidiuretic hormone (ADH)
   C. Oxytocin
   D. Cortisol

Answer 20

B. Antidiuretic hormone (ADH)
📌 Rationale: Diabetes insipidus results from ADH deficiency, causing polyuria, polydipsia, and dilute urine due to the kidneys’ inability to concentrate urine.

Question 21

7. A 6-year-old boy is diagnosed with a pituitary tumor. He presents with excessive height, headaches, and visual disturbances. His skull X-ray reveals an enlarged sella turcica. What is the most likely diagnosis?
   A. Growth hormone deficiency
   B. Pituitary gigantism
   C. Cushing’s disease
   D. Turner syndrome

Answer 21

B. Pituitary gigantism
📌 Rationale: Excess GH secretion in children before epiphyseal closure leads to gigantism, characterized by rapid growth, vision problems (tumor compression), and an enlarged sella turcica.

Question 22

IV. Growth Hormones
8. A 4-year-old girl has been diagnosed with Growth Hormone Deficiency (GHD). Which of the following is NOT a function of growth hormone?
A. Stimulating protein synthesis
B. Increasing glucose uptake by cells
C. Promoting lipolysis
D. Stimulating bone growth

Answer 22

B. Increasing glucose uptake by cells
📌 Rationale: GH actually decreases glucose uptake by cells, promoting hyperglycemia. It stimulates protein synthesis, promotes fat utilization (lipolysis), and stimulates linear bone growth.

Question 23

9. A 5-year-old boy with proportionate short stature undergoes a GH stimulation test using insulin-induced hypoglycemia. After the test, his GH levels remain low. What is the next best step in management?
   A. MRI of the pituitary gland
   B. Start corticosteroid therapy
   C. Thyroid function tests
   D. Serum calcium levels

Answer 23

A. MRI of the pituitary gland
📌 Rationale: Failure of GH levels to rise after stimulation suggests pituitary dysfunction. MRI is needed to rule out a pituitary tumor or structural abnormality.

Question 24

10. A 15-year-old girl presents with delayed puberty and short stature. She has a webbed neck, low hairline, and widely spaced nipples. Her karyotype reveals 45, XO. What is the most appropriate treatment for her growth delay?
    A. Thyroxine
    B. Growth hormone therapy
    C. Corticosteroids
    D. Testosterone replacement

Answer 24

B. Growth hormone therapy
📌 Rationale: This patient has Turner syndrome (45, XO), which is associated with short stature and delayed puberty. GH therapy is essential for height improvement before epiphyseal closure.

Question 25

11. What is the main reason growth hormone therapy is ineffective after puberty? A. GH receptors become unresponsive B. Bone epiphyses close C. GH secretion is permanently suppressed D. GH is metabolized too quickly

Answer 25

B. Bone epiphyses close 📌 Rationale: GH promotes bone lengthening, but this effect stops once epiphyseal plates fuse, making GH therapy ineffective after puberty.

Question 26

12. Which of the following is NOT a method used to evaluate a child's growth? A. Mid-parental height B. Bone age X-ray C. Growth velocity D. Serum insulin levels

Answer 26

D. Serum insulin levels 📌 Rationale: Growth evaluation involves mid-parental height, bone age, and growth velocity. Insulin levels are not a standard growth assessment tool.

Question 27

1. A 6-year-old boy presents to the clinic with concerns about being the shortest in his class. His parents state that he has been growing slowly compared to his peers. His growth chart shows a height below the 3rd percentile, but his growth velocity is within normal limits. His father is 5’4” and his mother is 5’0”. What is the most likely diagnosis? A. Constitutional delay of growth B. Familial short stature C. Growth hormone deficiency D. Hypothyroidism

Answer 27

B. Familial short stature 📌 Rationale: This child has short parents and normal growth velocity, which are characteristic of familial short stature. In contrast, constitutional delay involves delayed bone age, GH deficiency has slow growth velocity, and hypothyroidism presents with other systemic symptoms.

Question 28

2. A 10-year-old girl has a height below the 3rd percentile with a delayed bone age. Her growth velocity is approximately 4 cm per year. Her pubertal development is also delayed. What is the most likely diagnosis? A. Familial short stature B. Constitutional growth delay C. Hypopituitarism D. Turner syndrome

Answer 28

B. Constitutional growth delay 📌 Rationale: Constitutional growth delay presents with delayed bone age and slow growth, but these children eventually catch up to their expected adult height. Familial short stature has a normal bone age, hypopituitarism presents with multiple pituitary hormone deficiencies, and Turner syndrome would show other dysmorphic features.

Question 29

3. A 7-year-old boy presents with short stature and skeletal abnormalities. Physical examination reveals bowing of the legs and a rachitic rosary on his ribs. What is the most likely diagnosis? A. Achondroplasia B. Rickets C. Growth hormone deficiency D. Turner syndrome

Answer 29

B. Rickets 📌 Rationale: Vitamin D deficiency (Rickets) leads to bowed legs, rachitic rosary (beading along ribs), and growth impairment due to defective bone mineralization. Achondroplasia presents with disproportionate dwarfism, GH deficiency causes proportionate short stature, and Turner syndrome features webbed neck and ovarian failure.

Question 30

4. A 5-year-old girl is evaluated for short stature. Her growth chart shows a height below the 3rd percentile with a growth velocity of only 3 cm per year. Bone age is delayed. Serum IGF-1 and IGF-BP3 levels are low. What is the most appropriate next step in diagnosis? A. Measure serum cortisol B. Growth hormone stimulation test C. Thyroid function test D. Bone marrow biopsy

Answer 30

B. Growth hormone stimulation test 📌 Rationale: GH deficiency is confirmed with a stimulation test, such as insulin-induced hypoglycemia, since random GH levels fluctuate. Low IGF-1 and IGF-BP3 suggest GH deficiency, making stimulation testing the logical next step.

Question 31

5. A 4-year-old boy with proportionate short stature is diagnosed with GH deficiency. Which of the following is NOT a function of growth hormone? A. Protein synthesis B. Lipolysis C. Increased glucose uptake D. Linear bone growth

Answer 31

C. Increased glucose uptake 📌 Rationale: GH decreases glucose uptake by cells, leading to insulin resistance. It promotes protein synthesis, lipolysis (fat breakdown), and bone growth by acting on the liver to produce IGF-1.

Question 32

6. A 7-year-old boy is suspected of having GH deficiency. His bone age is found to be delayed. Which of the following is the BEST method to assess his GH secretion? A. Random GH level B. GH stimulation test C. Serum calcium levels D. Thyroid function test

Answer 32

B. GH stimulation test 📌 Rationale: Since GH secretion is pulsatile, a random GH level is unreliable. Instead, GH stimulation tests (e.g., insulin-induced hypoglycemia) confirm GH deficiency.

Question 33

7. A 10-year-old girl with a history of GH deficiency has been receiving GH therapy. What is the major requirement for GH therapy to be effective? A. High-calcium diet B. Open epiphyseal growth plates C. Normal adrenal function D. Puberty onset

Answer 33

B. Open epiphyseal growth plates 📌 Rationale: GH therapy is only effective before epiphyseal closure. Once the growth plates fuse (post-puberty), GH no longer increases height.

Question 34

8. A 6-year-old boy presents with excessive height for age, frequent headaches, and occasional visual disturbances. Skull X-ray reveals an enlarged sella turcica. What is the most likely diagnosis? A. Growth hormone deficiency B. Pituitary gigantism C. Cushing’s disease D. Turner syndrome

Answer 34

B. Pituitary gigantism 📌 Rationale: Excess GH secretion before epiphyseal closure causes gigantism. Headaches and vision problems suggest a pituitary adenoma, which can be confirmed by MRI of the pituitary.

Question 35

9. Which of the following best describes the difference between gigantism and acromegaly? A. Gigantism occurs after epiphyseal closure, while acromegaly occurs before B. Gigantism results from a pituitary tumor, while acromegaly does not C. Gigantism occurs before epiphyseal closure, while acromegaly occurs after D. Gigantism is caused by excess cortisol, while acromegaly is caused by excess GH

Answer 35

C. Gigantism occurs before epiphyseal closure, while acromegaly occurs after 📌 Rationale: Gigantism occurs in children before epiphyseal closure, leading to excessive height growth. Acromegaly occurs after closure, resulting in bone thickening and soft tissue overgrowth. Both are caused by GH excess from a pituitary adenoma.

Question 36

10. A 9-year-old boy presents with rapid growth and excessive sweating. He has a large forehead and coarse facial features. His parents report that his shoes and gloves have become too small for him. What is the most likely cause? A. Turner syndrome B. Pituitary gigantism C. Cushing syndrome D. Congenital hypothyroidism

Answer 36

B. Pituitary gigantism 📌 Rationale: Gigantism due to GH excess causes excessive height, coarse facial features, and soft tissue enlargement.

Question 37

11. A child diagnosed with pituitary gigantism undergoes MRI, which confirms a pituitary adenoma. What is the most appropriate first-line treatment? A. Radiation therapy B. Growth hormone replacement C. Transsphenoidal surgery D. Lifelong corticosteroid therapy

Answer 37

C. Transsphenoidal surgery 📌 Rationale: The first-line treatment for a GH-secreting pituitary adenoma is surgical removal via transsphenoidal approach. If surgery is not effective, radiation or GH-suppressing drugs (e.g., somatostatin analogs) can be considered.

Question 38

1. Which of the following steps is NOT involved in thyroid hormone biosynthesis? A. Iodide entry into the thyroid gland B. Oxidation of iodide to iodine C. Coupling of iodinated tyrosine residues D. Direct synthesis of T3 from cholesterol

Answer 38

D. Direct synthesis of T3 from cholesterol 📌 Rationale: Thyroid hormone biosynthesis begins with iodide uptake, which is oxidized to iodine. Iodine combines with tyrosine to form monoiodotyrosine (MIT) and diiodotyrosine (DIT), which then couple to form T3 (MIT + DIT) and T4 (DIT + DIT). Cholesterol is not involved in thyroid hormone production.

Question 39

2. A 6-year-old boy presents with fatigue, weight gain, and cold intolerance. Laboratory tests reveal elevated TSH and low T4. What is the most likely cause of his hypothyroidism? A. Pituitary dysfunction B. Iodine deficiency C. Primary thyroid failure D. Hypothalamic tumor

Answer 39

C. Primary thyroid failure 📌 Rationale: High TSH with low T4 suggests primary hypothyroidism, most commonly due to thyroid gland dysfunction. If the problem was at the pituitary or hypothalamic level, TSH would be low or normal.

Question 40

3. A newborn fails to pass meconium within 48 hours and has prolonged jaundice. Physical examination reveals a large anterior fontanelle, macroglossia, and an umbilical hernia. Which laboratory finding would confirm the suspected diagnosis? A. Low T4, High TSH B. Low TSH, Low T4 C. High T4, Low TSH D. Normal T4, Normal TSH

Answer 40

A. Low T4, High TSH 📌 Rationale: These findings are hallmark features of congenital hypothyroidism, which is confirmed by low T4 and high TSH in newborn screening. Early treatment with levothyroxine is critical to prevent intellectual disability.

Question 41

4. A 2-week-old infant diagnosed with congenital hypothyroidism is started on levothyroxine. What is the appropriate initial dose for neonates? A. 2–3 µg/kg/day B. 5–6 µg/kg/day C. 10–15 µg/kg/day D. 20 µg/kg/day

Answer 41

C. 10–15 µg/kg/day 📌 Rationale: Infants require higher doses of levothyroxine (10–15 µg/kg/day) due to their high metabolic demand and brain development needs.

Question 42

5. A 12-year-old girl presents with weight loss despite a good appetite, tachycardia, exophthalmos, and a diffuse goiter. What is the most likely diagnosis? A. Hashimoto thyroiditis B. Graves’ disease C. Congenital hypothyroidism D. Euthyroid goiter

Answer 42

B. Graves’ disease 📌 Rationale: Graves' disease is the most common cause of pediatric hyperthyroidism. It is characterized by diffuse goiter, exophthalmos, weight loss, and tachycardia due to excessive thyroid hormone production.

Question 43

6. A 14-year-old boy is diagnosed with hyperthyroidism due to Graves' disease. Which of the following is NOT a standard treatment option? A. Methimazole B. Radioactive iodine C. Levothyroxine D. Beta-blockers

Answer 43

C. Levothyroxine 📌 Rationale: Levothyroxine is used to treat hypothyroidism, not hyperthyroidism. Standard treatments for Graves' disease include methimazole (first-line antithyroid drug), radioactive iodine (if medication fails), and beta-blockers for symptom control.

Question 44

7. A 10-year-old girl with Graves' disease is started on methimazole. Which of the following is the most serious potential side effect? A. Rash B. Agranulocytosis C. Weight gain D. Hypoglycemia

Answer 44

B. Agranulocytosis 📌 Rationale: Methimazole can cause agranulocytosis, a severe drop in white blood cells, leading to life-threatening infections. Any patient on methimazole who develops a sore throat or fever should have an urgent WBC check.

Question 45

8. A 13-year-old boy is found to have an enlarged thyroid gland but is clinically euthyroid. Which of the following is the most likely cause? A. Iodine deficiency B. Graves' disease C. Congenital hypothyroidism D. Thyroid carcinoma

Answer 45

A. Iodine deficiency 📌 Rationale: Non-toxic (euthyroid) goiter is most commonly due to iodine deficiency. Patients may have normal thyroid hormone levels but an enlarged thyroid as the gland attempts to compensate for iodine deficiency.

Question 46

9. A 9-year-old girl presents with an enlarged thyroid that is soft and doughy on palpation. There are no signs of hyperthyroidism or hypothyroidism. Which of the following is the most likely diagnosis? A. Diffuse goiter B. Nodular goiter C. Thyroid carcinoma D. Cretinism

Answer 46

A. Diffuse goiter 📌 Rationale: A diffuse, soft, doughy thyroid without symptoms of hypo/hyperthyroidism suggests a simple (euthyroid) goiter. If hard or nodular, malignancy should be considered.

Question 47

10. A child with a large goiter and suspected iodine deficiency is being evaluated. What is the best initial diagnostic test? A. Thyroid function tests (T3, T4, TSH) B. Thyroid ultrasound C. Fine-needle aspiration biopsy D. Serum calcium levels

Answer 47

A. Thyroid function tests (T3, T4, TSH) 📌 Rationale: The first step in evaluating a goiter is assessing thyroid function. If euthyroid, iodine deficiency is suspected. If hypothyroid or hyperthyroid, further investigation is needed.

Question 48

1. A 2-year-old boy presents with bowed legs, frontal bossing, and a waddling gait. His mother reports that he was exclusively breastfed and does not receive vitamin D supplementation. Which of the following laboratory findings would confirm the diagnosis of rickets? A. ↑ Serum calcium, ↑ Phosphorus, ↑ Alkaline phosphatase B. ↓ Serum calcium, ↓ Phosphorus, ↑ Alkaline phosphatase C. ↑ Serum calcium, ↓ Phosphorus, ↓ Alkaline phosphatase D. ↓ Serum calcium, ↑ Phosphorus, ↑ Alkaline phosphatase

Answer 48

B. ↓ Serum calcium, ↓ Phosphorus, ↑ Alkaline phosphatase 📌 Rationale: Vitamin D deficiency leads to impaired calcium and phosphorus absorption, causing low calcium and phosphorus levels. Alkaline phosphatase is elevated due to increased bone turnover.

Question 49

2. A 4-year-old girl presents with delayed walking, frequent falls, and bowing of the legs. X-ray shows cupping and fraying of the metaphyses. What is the primary treatment for her condition? A. Calcium supplements only B. Vitamin C supplementation C. Vitamin D supplementation D. Growth hormone therapy

Answer 49

C. Vitamin D supplementation 📌 Rationale: Rickets is caused by vitamin D deficiency, leading to defective bone mineralization. Vitamin D supplementation corrects calcium and phosphorus absorption, allowing proper bone development.

Question 50

3. A 1-week-old newborn presents with dehydration, vomiting, and hyperpigmentation. Lab results show hyponatremia, hyperkalemia, and metabolic acidosis. What is the most likely diagnosis? A. Pheochromocytoma B. Congenital adrenal hyperplasia (CAH) C. Cushing syndrome D. Diabetes insipidus

Answer 50

B. Congenital adrenal hyperplasia (CAH) 📌 Rationale: CAH due to 21-hydroxylase deficiency leads to salt-wasting (hyponatremia, hyperkalemia) and adrenal insufficiency (vomiting, dehydration). Hyperpigmentation occurs due to excess ACTH production.

Question 51

4. A newborn girl presents with ambiguous genitalia. Laboratory tests reveal elevated 17-hydroxyprogesterone. What is the best initial treatment? A. Levothyroxine B. Hydrocortisone and fludrocortisone C. Insulin D. Estrogen replacement therapy

Answer 51

B. Hydrocortisone and fludrocortisone 📌 Rationale: CAH requires glucocorticoid (hydrocortisone) replacement to suppress ACTH and androgen production, and mineralocorticoid (fludrocortisone) replacement for salt retention.

Question 52

5. A 9-year-old girl presents with weight gain, a round "moon" face, abdominal striae, and hypertension. What is the most likely diagnosis? A. Growth hormone deficiency B. Congenital adrenal hyperplasia C. Cushing syndrome D. Turner syndrome

Answer 52

C. Cushing syndrome 📌 Rationale: Cushing syndrome is caused by excess cortisol secretion, leading to central obesity, moon facies, striae, and hypertension.

Question 53

6. A child suspected of having Cushing syndrome undergoes a 24-hour urinary free cortisol test, which shows elevated levels. What is the next best step in management? A. CT scan of the adrenal glands B. Start hydrocortisone therapy C. Perform a GH stimulation test D. Thyroid function test

Answer 53

A. CT scan of the adrenal glands 📌 Rationale: If Cushing syndrome is confirmed, imaging is necessary to identify the source (adrenal tumor or pituitary tumor).

Question 54

7. A 13-year-old girl presents with short stature, webbed neck, and delayed puberty. Physical examination reveals widely spaced nipples. What is the most likely diagnosis? A. Turner syndrome B. Klinefelter syndrome C. Androgen insensitivity syndrome D. Hypothyroidism

Answer 54

A. Turner syndrome 📌 Rationale: Turner syndrome (45, XO) is characterized by short stature, webbed neck, and gonadal dysgenesis leading to delayed puberty.

Question 55

8. Which of the following tests confirms the diagnosis of Turner syndrome? A. Serum FSH and LH levels B. Growth hormone stimulation test C. Karyotype analysis D. Thyroid function test

Answer 55

C. Karyotype analysis 📌 Rationale: Turner syndrome is diagnosed by karyotyping, revealing 45, XO.

Question 56

9. A 14-year-old girl with Turner syndrome has not developed secondary sexual characteristics. What is the best treatment? A. Growth hormone therapy B. Estrogen replacement therapy C. Androgen supplementation D. Radioactive iodine therapy

Answer 56

B. Estrogen replacement therapy 📌 Rationale: Turner syndrome leads to ovarian failure, requiring estrogen replacement for puberty and bone health.

Question 57

10. A 6-year-old girl presents with breast development and pubic hair. Bone age is advanced for her chronological age. What is the best next step in management? A. Observation and follow-up B. Brain MRI C. Growth hormone therapy D. Levothyroxine therapy

Answer 57

B. Brain MRI 📌 Rationale: Central precocious puberty (early activation of the HPG axis) may be caused by a CNS tumor. MRI is required to rule out intracranial pathology.

Question 58

11. Which of the following is the first sign of puberty in girls? A. Menarche B. Growth spurt C. Breast budding (thelarche) D. Pubic hair development

Answer 58

C. Breast budding (thelarche) 📌 Rationale: The first sign of puberty in girls is breast budding, followed by pubic hair growth and menarche.

Question 59

12. A 7-year-old boy presents with pubic hair growth, testicular enlargement, and deepening of the voice. What is the most likely diagnosis? A. Turner syndrome B. Congenital adrenal hyperplasia C. Precocious puberty D. Hypothyroidism

Answer 59

C. Precocious puberty 📌 Rationale: Precocious puberty is defined as the development of secondary sexual characteristics before age 8 in girls and before age 9 in boys.

Question 60

13. Which of the following is the treatment for central precocious puberty? A. Growth hormone therapy B. Gonadotropin-releasing hormone (GnRH) agonists C. Testosterone replacement D. Fludrocortisone

Answer 60

B. Gonadotropin-releasing hormone (GnRH) agonists 📌 Rationale: GnRH agonists suppress early puberty by inhibiting the release of LH and FSH.