Endocrine Flashcards
(200 cards)
1
Q
- What are the hormone levels in primary adrenal insufficiency?
A
Hormones: Low cortisol, high ACTH
- Hyponatremia, hyperkalemia
- May have elevated renin
2
Q
- What is the screening test for congenital adrenal hyperplasia in newborns?
A
Screening test: Serum 17-hydroxyprogesterone level on newborn screening
- Done within first few days of life
3
Q
- What is the most common cause of adrenal insufficiency in infancy?
A
Most common cause: Congenital Adrenal Hyperplasia (21-hydroxylase deficiency)
- Autosomal recessive
- Presents with salt-wasting crisis
4
Q
- What adrenal tumors may cause peripheral precocious puberty?
A
Tumors: Adrenocortical tumors (secrete androgens or cortisol)
- Features: Rapid virilization, Cushingoid features
5
Q
- How is adrenal insufficiency screened in children with pituitary disease?
A
Screening: Morning cortisol and ACTH levels
- If low/indeterminate, do ACTH stimulation test
6
Q
- How is Cushing disease differentiated from ectopic ACTH production?
A
Differentiation: High-dose dexamethasone suppression test or CRH stimulation test
- MRI pituitary and ACTH levels help localize source
7
Q
- How is salt-wasting congenital adrenal hyperplasia treated acutely?
A
Treatment: IV hydrocortisone, normal saline bolus, glucose if needed
- Monitor electrolytes, start fludrocortisone after stabilization
8
Q
- What is the pathophysiology of X-linked hypophosphatemic rickets?
A
Pathophysiology: PHEX gene mutation → renal phosphate wasting
- Low serum phosphate despite normal intake
9
Q
- A child with seizures, hypocalcemia, and hyperphosphatemia. PTH is low. What is the diagnosis?
A
Diagnosis: Hypoparathyroidism
- Low PTH, low calcium, high phosphate
- May be congenital or post-surgical
10
Q
- What are the treatment options for X-linked hypophosphatemia?
A
Treatment: Oral phosphate + active vitamin D (calcitriol)
- Monitor for hyperparathyroidism and nephrocalcinosis
11
Q
- What lab findings are characteristic of vitamin D deficiency rickets?
A
Labs: Low calcium, low phosphate, high ALP, low 25(OH)D
- Radiology: Cupping/fraying at metaphyses
- Clinical: Rachitic rosary, bowed legs
12
Q
- What is the pathophysiology of hereditary vitamin D resistant rickets (HVDRR)?
A
Pathophysiology: Mutation in vitamin D receptor
- Labs: Low calcium, high phosphate, very high 1,25(OH)2 vitamin D
- Resistant to vitamin D therapy
13
Q
- What are the typical features of X-linked hypophosphatemic rickets?
A
Features: Short stature, bowed legs, dental abscesses
- Serum calcium normal, phosphate low, ALP high
14
Q
- What is the recommended monitoring during treatment of rickets?
A
Monitoring: Serum calcium, phosphate, ALP, PTH, urinary calcium
- Adjust therapy to avoid complications
15
Q
- A neonate has jitteriness, seizures, and Chvostek sign. Serum calcium is 6.5 mg/dL. What is the most likely cause?
A
Likely cause: Neonatal Hypocalcemia
- Early or late onset
- May be due to maternal diabetes, prematurity, or hypoparathyroidism
16
Q
- What is the difference between nutritional and genetic rickets?
A
Nutritional: Low vitamin D, responds to supplementation
- Genetic: Usually phosphate-wasting, often requires lifelong therapy
17
Q
- What are the signs of cerebral edema in a child with DKA?
A
Signs: Headache, altered consciousness, bradycardia, hypertension, vomiting, papilledema
- Must monitor neuro status closely
18
Q
- What is the most serious complication during treatment of DKA?
A
Most serious complication: Cerebral edema
- Can be life-threatening
- Typically occurs in first 12–24 hrs of treatment
19
Q
- What is the most important initial management step in DKA?
A
Initial step: Fluid resuscitation with isotonic saline
- Followed by insulin and correction of electrolytes
20
Q
- What is the role of insulin-like growth factor binding protein-3 (IGFBP-3)?
A
Role: Marker of GH activity like IGF-1
- Less influenced by nutritional status
- Low in GH deficiency
21
Q
- What are the clinical features of diabetic ketoacidosis (DKA)?
A
Features: Polyuria, polydipsia, vomiting, abdominal pain, Kussmaul respiration, dehydration, fruity breath odor
22
Q
- What insulin regimen is considered standard of care in pediatric type 1 diabetes?
A
Standard of care: Basal-bolus regimen
- Long-acting insulin (glargine/detemir) + rapid-acting insulin (lispro/aspart) before meals
23
Q
- What is the target HbA1c in children with type 1 diabetes?
A
Target HbA1c: <7.5% for most children
- Individualized goals based on age and risk of hypoglycemia
24
Q
- What is the honeymoon phase in type 1 diabetes?
A
Honeymoon phase: Temporary period of decreased insulin requirement
- Due to partial recovery of beta cells
- Can last weeks to months
25
42. What is the diagnostic criteria for type 1 diabetes in children?
Diagnostic criteria: FPG ≥126 mg/dL, 2-hour OGTT ≥200 mg/dL, random glucose ≥200 mg/dL with symptoms, or HbA1c ≥6.5%
26
41. What antibodies are commonly positive in type 1 diabetes mellitus?
Common antibodies: GAD65, IA-2, insulin autoantibodies, ZnT8
- Present in ~90% of T1DM at diagnosis
- Useful for diagnosis and screening siblings
27
52. A 14-year-old obese boy presents with acanthosis nigricans and fasting glucose of 130 mg/dL. What is the likely diagnosis?
Diagnosis: Type 2 Diabetes Mellitus
- Features: Obesity, insulin resistance (acanthosis), elevated fasting glucose
- Confirm with OGTT or HbA1c
28
53. What is the first-line treatment for type 2 diabetes in children?
First-line: Lifestyle modification + Metformin
- Approved for children >10 years
- Insulin if symptomatic or very high glucose
29
32. How is central diabetes insipidus treated?
Treatment: Desmopressin (DDAVP)
- Intranasal, oral, or parenteral forms
- Monitor for hyponatremia
30
31. What is the typical presentation of central diabetes insipidus in a child?
Presentation: Polyuria, polydipsia, dehydration
- Hypernatremia and low urine osmolality
- May be idiopathic or due to CNS insult
31
49. How is cerebral edema in DKA treated?
Treatment: Mannitol or 3% hypertonic saline
- Reduce fluids, elevate head of bed
- ICU monitoring required
32
29. What test differentiates central from nephrogenic diabetes insipidus?
Test: Water deprivation test
- Followed by desmopressin administration
- Central DI improves with desmopressin; nephrogenic does not
33
156. What are the typical features of congenital hyperinsulinism?
Features: Persistent neonatal hypoglycemia, high insulin, macrosomia
- Can cause seizures
- Treat with diazoxide, surgery in severe cases
34
30. What are the clinical features of diabetes insipidus?
Features: Polyuria, polydipsia, dehydration
- Hypernatremia, dilute urine
- Can be central or nephrogenic
35
181. What are the common endocrine complications of childhood cancer survivors?
Complications: GH deficiency, hypothyroidism, gonadal failure, adrenal insufficiency, metabolic syndrome
- Depends on therapy type and age
36
182. How does cranial irradiation affect endocrine function?
Effect: Damages hypothalamic-pituitary axis
- Can cause GH, TSH, LH/FSH, and ACTH deficiencies
- Dose-dependent
37
185. What is the first endocrine axis affected by cranial irradiation?
First affected: GH axis
- Very sensitive to radiation
- Screening recommended in exposed patients
38
200. What are the endocrine causes of hypertension in children?
Causes: CAH, hyperaldosteronism, Cushing syndrome, pheochromocytoma, Liddle syndrome
- Must differentiate endocrine vs renal causes
39
76. What are the endocrine complications of Turner syndrome?
Complications: Hypothyroidism, diabetes, ovarian failure, osteoporosis
- Also risk of cardiac defects (coarctation, bicuspid aortic valve)
40
74. What are the typical features of Turner syndrome?
Features: Short stature, webbed neck, low posterior hairline, shield chest, lymphedema, ovarian failure, cardiac anomalies
41
73. How is Turner syndrome diagnosed?
Diagnosis: Karyotype analysis (45,X or mosaicism)
- Can be done prenatally or postnatally based on clinical features
42
80. What are the key features of Noonan syndrome?
Features: Short stature, webbed neck, ptosis, cardiac defects (pulmonary stenosis), cryptorchidism
- PTPN11 mutation
43
196. What is the clinical presentation of 46,XY gonadal dysgenesis?
Presentation: Female external genitalia, streak gonads, primary amenorrhea
- Karyotype: 46,XY
- Risk of gonadoblastoma
44
194. How does Turner syndrome affect fertility and how is it assessed?
Turner syndrome: Ovarian failure leads to infertility
- AMH and inhibin B help assess ovarian reserve
45
112. What is the genetic mutation responsible for MEN2 syndromes?
Mutation: RET proto-oncogene
- Autosomal dominant inheritance
- Genotype-phenotype correlations guide screening
46
68. What are the causes of proportionate short stature?
Causes: Constitutional delay, familial short stature, GH deficiency, hypothyroidism, chronic disease, psychosocial dwarfism
47
10. What is the stimulation test used to diagnose growth hormone deficiency?
Stimulation test: Insulin tolerance test or Clonidine stimulation test
- Measure GH peak response
- GH <10 ng/mL confirms deficiency
48
60. A 10-year-old girl presents with tall stature, advanced bone age, and high IGF-1. What is the diagnosis?
Diagnosis: Gigantism (if before epiphyseal closure)
- Features: Tall stature, high IGF-1
- Confirm with GH suppression test
49
59. What test is used to diagnose growth hormone excess (acromegaly/gigantism) in children?
Test: Oral glucose suppression test
- GH levels fail to suppress in GH excess
- Confirm with MRI for pituitary adenoma
50
67. What are the key differences between proportionate and disproportionate short stature?
Proportionate: All body parts small (endocrine/metabolic causes)
- Disproportionate: Short limbs vs trunk (skeletal dysplasias)
51
169. What is the genetic cause of Laron syndrome?
Cause: GH receptor mutation (GHR gene)
- GH levels are high but IGF-1 is low due to receptor insensitivity
52
69. What test is used to assess bone age?
Test: Left hand/wrist X-ray compared to standard atlas
- Used to estimate skeletal maturity
53
70. How does bone age help differentiate types of short stature?
Helps differentiate:
- Delayed bone age: Constitutional delay, GH deficiency
- Normal bone age: Familial short stature
- Advanced bone age: Precocious puberty, obesity
54
136. A 14-year-old girl with no breast development and normal bone age. What is the likely diagnosis?
Likely diagnosis: Hypogonadism (evaluate FSH/LH levels)
- May be hypergonadotropic or hypogonadotropic
55
170. What are the clinical features of Laron syndrome?
Features: Short stature, frontal bossing, small chin, delayed bone age, obesity
- IGF-1 therapy may help
56
111. What are the endocrine tumors associated with MEN2A?
Tumors: Medullary thyroid carcinoma, pheochromocytoma, parathyroid hyperplasia
- MEN2A is a subtype of MEN2
57
110. What endocrine tumors are associated with MEN1 syndrome?
Tumors: Parathyroid adenoma, pancreatic neuroendocrine tumors (e.g., insulinoma), pituitary adenoma
- Mutation in MEN1 gene
58
56. What is the best initial screening test for Cushing syndrome in children?
Best initial test: 24-hour urinary free cortisol or low-dose dexamethasone suppression test
- Midnight salivary cortisol may also be used
59
155. What endocrine disorders are screened for in standard neonatal screening programs?
Screened conditions: Congenital hypothyroidism, CAH (21-OH), G6PD, galactosemia, PKU, biotinidase deficiency
- Varies by country
60
19. A newborn with ambiguous genitalia, hypotension, and hyperkalemia. What is the likely enzyme deficiency?
Likely enzyme deficiency: 21-hydroxylase deficiency
- CAH (Salt-wasting form)
- Ambiguous genitalia in girls, adrenal crisis
61
21. A newborn is noted to have ambiguous genitalia, hypotension, and hyponatremia. What is the definitive test for diagnosis?
Definitive test: 17-hydroxyprogesterone level
- Elevated in 21-hydroxylase deficiency
- Confirm with ACTH stimulation test
62
121. What is the most common cause of ambiguous genitalia in newborn females?
Most common cause: 21-hydroxylase deficiency (Congenital Adrenal Hyperplasia)
- Causes virilization of 46,XX females
63
124. A newborn male with under-virilization and salt-wasting. What enzyme deficiency is suspected?
Suspected deficiency: 17-beta hydroxysteroid dehydrogenase or 5-alpha reductase deficiency
- Leads to undervirilized 46,XY infants
64
78. Which chromosomal syndrome is associated with hypogonadism, obesity, and intellectual disability?
Syndrome: Prader-Willi Syndrome
- Features: Hypotonia, feeding difficulty → obesity, hypogonadism, ID
- Genetic: Paternal 15q11-q13 deletion
65
157. What are the endocrine causes of obesity in children?
Causes: Hypothyroidism, Cushing syndrome, hypothalamic dysfunction, GH deficiency, pseudohypoparathyroidism
- All associated with reduced growth velocity
66
55. A child with obesity, moon facies, and purple striae. What endocrine disorder is suspected?
Suspected disorder: Cushing Syndrome
- Hypercortisolism due to endogenous or exogenous causes
- Signs: Moon face, central obesity, striae
67
51. What are the diagnostic criteria for metabolic syndrome in children?
Criteria: ≥3 of the following—central obesity, elevated triglycerides, low HDL, hypertension, impaired fasting glucose
- Use age-specific cutoffs
68
158. A child with hypotonia, obesity, and hypogonadism. What syndrome is suspected?
Suspected syndrome: Prader-Willi Syndrome
- Genetic: Paternal 15q11-q13 deletion
- Features: Neonatal hypotonia → obesity, hypogonadism
69
164. What is the function of leptin and its role in pediatric obesity?
Function: Regulates appetite and energy expenditure
- Leptin resistance or deficiency contributes to early-onset obesity
70
167. What is the typical presentation of Kallmann syndrome in boys?
Presentation: Delayed puberty, anosmia, small testes, cryptorchidism
- Low LH/FSH and testosterone
71
125. What is the cause of 17-hydroxylase deficiency and what are its features?
Cause: CYP17A1 mutation
- Features: Hypertension, hypokalemia, sexual infantilism, XY undervirilization
72
126. What are the biochemical features of 3-beta hydroxysteroid dehydrogenase deficiency?
Features: Elevated 17-hydroxypregnenolone, DHEA
- Salt-wasting, ambiguous genitalia in both sexes
- Rare form of CAH
73
127. A neonate presents with hyponatremia, hyperkalemia, and hypoglycemia. What should be considered?
Consider: Primary adrenal insufficiency
- Includes CAH, adrenal hypoplasia, or familial glucocorticoid deficiency
74
171. What is the role of IGF-1 and IGFBP-3 in growth evaluation?
IGF-1 and IGFBP-3 reflect GH activity
- Low in GH deficiency and chronic illness
- Used to assess GH axis before stimulation tests
75
199. What is the cause of 46,XX testicular DSD (de la Chapelle syndrome)?
Cause: Translocation of SRY gene to X chromosome
- Phenotypic males with 46,XX karyotype
- Infertile due to lack of Y genes for spermatogenesis
76
106. What is the role of PTH-related protein (PTHrP) in pediatric endocrinology?
PTHrP: Mimics PTH action but not measured in standard PTH tests
- Elevated in malignancy-related hypercalcemia
77
159. What are the features of Albright Hereditary Osteodystrophy?
Features: Short stature, brachydactyly, round face, subcutaneous ossifications
- Often associated with PTH resistance (type 1a pseudohypoparathyroidism)
78
168. What hormones are deficient in septo-optic dysplasia?
Hormones deficient: GH, ACTH, TSH, LH/FSH
- Associated with optic nerve hypoplasia and midline defects
79
122. What enzyme is deficient in 21-hydroxylase deficiency?
Enzyme: CYP21A2
- Deficiency causes impaired cortisol and aldosterone synthesis
- Leads to androgen excess
80
166. What are the hormonal findings in familial glucocorticoid deficiency?
Findings: Low cortisol, high ACTH, normal aldosterone
- Mutation affects ACTH receptor (MC2R)
81
128. What is the typical karyotype in androgen insensitivity syndrome?
Typical karyotype: 46,XY
- Complete insensitivity → female phenotype
- Mutation in androgen receptor gene
82
129. How does partial androgen insensitivity syndrome present in childhood?
Presentation: Hypospadias, micropenis, bifid scrotum
- Variable response to androgens
- May present as undervirilized males
83
130. What is the difference between complete and partial androgen insensitivity syndrome?
Complete: Female phenotype despite 46,XY
- Partial: Ambiguous genitalia or undervirilized male phenotype
84
133. What is the most common chromosomal cause of hypergonadotropic hypogonadism in girls?
Most common: Turner syndrome (45,X)
- Presents with short stature and delayed puberty
- Confirmed by karyotype
85
141. What are the signs of estrogen excess in prepubertal girls?
Signs: Breast development, vaginal bleeding, accelerated growth
- Suggests estrogen exposure or ovarian pathology
86
145. What is the pathophysiology of McCune-Albright syndrome?
Pathophysiology: GNAS1 activating mutation
- Leads to constitutive activation of G-protein signaling
- GnRH-independent puberty
87
150. What is the function of the GnRH stimulation test?
Function: Differentiates central vs peripheral causes
- Central: Elevated LH after stimulation
- Peripheral: Blunted LH response
88
152. What is the most common cause of hyperprolactinemia in adolescents?
Most common cause: Functional (stress, medications like risperidone)
- Other causes: Prolactinoma, hypothyroidism
89
154. What are the endocrine causes of neonatal hypoglycemia?
Causes: Congenital hyperinsulinism, cortisol deficiency, GH deficiency, inborn errors of metabolism
- Present with jitteriness, seizures
90
120. What are the side effects of long-term glucocorticoid therapy in children?
Side effects: Growth suppression, obesity, osteoporosis, adrenal suppression, hypertension, Cushingoid features
91
119. What is the long-term management of CAH in children?
Long-term: Hydrocortisone (10–15 mg/m²/day) and fludrocortisone
- Monitor growth, electrolytes, androgen levels
- Adjust during illness or stress
92
117. A neonate presents with severe dehydration and hyperkalemia. What endocrine emergency should be suspected?
Suspected emergency: Salt-wasting crisis due to CAH (21-hydroxylase deficiency)
- Features: Hypovolemia, hyperkalemia, hypotension
93
165. What are the endocrine features of Laurence-Moon-Bardet-Biedl syndrome?
Features: Retinal dystrophy, polydactyly, obesity, hypogonadism, renal anomalies
- Autosomal recessive disorder
94
123. How is 11-beta hydroxylase deficiency distinguished from 21-hydroxylase deficiency?
11-beta: Causes hypertension due to deoxycorticosterone accumulation
- 21-hydroxylase: Causes hypotension and salt-wasting
95
109. What is the management of hypercalcemia in children?
Management: IV hydration, furosemide, calcitonin, bisphosphonates
- Treat underlying cause
96
107. A child presents with hypercalcemia and suppressed PTH. What is the next step?
Next step: Check PTHrP, vitamin D metabolites, assess for malignancy, consider genetic causes (e.g., FHH)
97
114. A child presents with mucosal neuromas and marfanoid habitus. What syndrome is suspected?
Suspected syndrome: MEN2B
- Features: Medullary thyroid carcinoma, pheochromocytoma, mucosal neuromas, marfanoid habitus
98
190. What are the endocrine side effects of long-term antiepileptic drug use?
Side effects: Osteopenia/osteoporosis (phenytoin), altered thyroid function, vitamin D metabolism changes
99
24. A child with 17-hydroxylase deficiency will have which clinical features?
Features: Hypertension, hypokalemia, lack of puberty, sexual infantilism
- Low cortisol, low androgens
- XY DSD due to low testosterone
100
176. What are the endocrine manifestations of DiGeorge syndrome?
Manifestations: Hypocalcemia due to hypoparathyroidism
- Can also have hypothyroidism and growth delay
101
22. What lab abnormalities are seen in 21-hydroxylase deficiency?
Labs: Low cortisol, high ACTH, high 17-OHP
- Hyponatremia, hyperkalemia
- Metabolic acidosis may be present
102
36. What is the most common cause of hypercalcemia in children?
Most common cause: Hyperparathyroidism or malignancy (e.g., leukemia, lymphoma)
- Also consider immobilization, vitamin D intoxication
103
37. What are the biochemical features of familial hypocalciuric hypercalcemia (FHH)?
Biochemical features: High serum calcium, low urinary calcium, normal/high PTH
- Asymptomatic, autosomal dominant
104
14. A girl has isolated premature breast development, normal growth, and no pubic hair. What is the diagnosis?
Diagnosis: Premature Thelarche
- Isolated breast development
- Normal bone age, no other signs of puberty
- Self-limited
105
39. What is the most common cause of hypocalcemia in adolescents?
Most common cause: Vitamin D deficiency
- Especially in those with limited sun exposure or dietary intake
106
40. A child with polyuria, polydipsia, hyperglycemia, and weight loss. What is the diagnosis?
Diagnosis: Type 1 Diabetes Mellitus (T1DM)
- Autoimmune destruction of beta cells
- Symptoms: Polyuria, polydipsia, weight loss
107
58. What is the most common cause of Cushing syndrome in children?
Most common cause: Exogenous corticosteroid use
- Endogenous: Pituitary adenoma (Cushing disease)
108
61. What are common causes of tall stature in children?
Causes: Familial tall stature, constitutional advancement of growth, endocrine (GH excess, precocious puberty), syndromes (Marfan, Sotos)
109
62. How is constitutional tall stature differentiated from pathologic causes?
Constitutional tall stature: Normal bone age, normal pubertal timing
- Pathologic: Advanced bone age or abnormal physical features
110
13. A 7-year-old boy with axillary odor and pubic hair but no testicular enlargement. What is the likely diagnosis?
Diagnosis: Premature Adrenarche
- Isolated pubic/axillary hair, body odor
- Normal testicular volume
- Due to early adrenal androgen production
111
63. A child has tall stature, learning difficulties, and small testes. What is the most likely diagnosis?
Diagnosis: Klinefelter Syndrome (47,XXY)
- Features: Tall, learning difficulty, hypogonadism
- Confirm with karyotype
112
26. What is the most common cause of hypopituitarism in children?
Most common cause: Craniopharyngioma
- Affects anterior pituitary
- Symptoms depend on hormone deficits
113
64. What are the features of Marfan syndrome?
Features: Arachnodactyly, high-arched palate, lens dislocation, aortic root dilation
- Mutation: FBN1 gene
114
66. What gene mutation causes achondroplasia?
Gene mutation: FGFR3 (fibroblast growth factor receptor 3)
- Gain-of-function mutation leads to impaired cartilage growth
115
12. A girl develops breast budding before age 8 and has elevated LH after GnRH stimulation. What is the diagnosis?
Diagnosis: Central (GnRH-dependent) Precocious Puberty
- GnRH stimulation shows pubertal LH response
- Consider MRI brain to rule out pathology
116
75. A girl with primary amenorrhea, webbed neck, and widely spaced nipples. What is the most likely karyotype?
Most likely karyotype: 45,X (monosomy X)
- Classic Turner syndrome
- Often diagnosed during evaluation for short stature or amenorrhea
117
7. What is the most common cause of hypocalcemia in neonates?
Most common cause: Maternal diabetes
- Causes functional hypoparathyroidism in neonate
- Other causes: prematurity, asphyxia
118
79. What hormone pattern is seen in primary gonadal failure?
Pattern: High LH and FSH (hypergonadotropic hypogonadism)
- Seen in gonadal dysgenesis, Turner syndrome, chemotherapy
119
197. What are the features of testotoxicosis?
Testotoxicosis: Familial male-limited precocious puberty
- LH-independent testosterone production
- Early virilization without gonadotropin elevation
120
188. What is the cosyntropin stimulation test and when is it used?
Test: Synthetic ACTH (cosyntropin) given IV or IM
- Normal response = cortisol >18 mcg/dL at 30–60 min
- Used to diagnose adrenal insufficiency
121
186. What endocrine problems can develop after hematopoietic stem cell transplant?
Problems: Gonadal failure, thyroid dysfunction, GH deficiency, metabolic abnormalities
- Due to chemo, TBI, or graft-vs-host disease
122
198. How is testotoxicosis managed?
Management: Antiandrogens (e.g., bicalutamide) + aromatase inhibitors
- Suppress testosterone effect and estrogen conversion
123
183. What hormone deficiencies are common after CNS tumors in children?
Deficiencies: GH most common, followed by TSH and ACTH
- Evaluate regularly post-therapy
124
178. What are the risks of overtreatment with vitamin D analogs?
Risks: Hypercalcemia, hypercalciuria, nephrocalcinosis
- Monitor calcium, phosphate, and urinary calcium regularly
125
2. A 12-year-old girl presents with weight loss, tremor, heat intolerance, and a goiter. What is the most likely diagnosis?
Diagnosis: Graves' Disease
- Autoimmune hyperthyroidism
- Features: Goiter, weight loss, tremor, tachycardia
- Labs: Low TSH, high free T4
126
65. A child with large head, frontal bossing, and short limbs. What is the diagnosis?
Diagnosis: Achondroplasia
- Short limbs, normal trunk length
- Large head with frontal bossing
- Autosomal dominant
127
25. What is the biochemical hallmark of 11-beta hydroxylase deficiency?
Biochemical hallmark: Elevated 11-deoxycortisol and androgens
- Leads to virilization and hypertension
128
153. How is prolactinoma diagnosed and treated in children?
Diagnosis: Elevated serum prolactin, MRI brain
- Treatment: Dopamine agonists (e.g., cabergoline, bromocriptine)
- Surgery if large/vision loss
129
151. What are the clinical features of prolactinoma in children?
Features: Galactorrhea, delayed puberty, amenorrhea, visual field defects
- Due to pituitary tumor secreting prolactin
130
162. What is the most common congenital cause of panhypopituitarism?
Most common: Midline brain defects (e.g., septo-optic dysplasia)
- May also be due to genetic mutations or acquired damage
131
161. What hormones are typically low in panhypopituitarism in children?
Low: ACTH, TSH, GH, LH, FSH, sometimes ADH
- Results in cortisol, thyroid, growth, and gonadal hormone deficiency
132
163. What is the clinical presentation of pituitary stalk interruption syndrome?
Presentation: Short stature, neonatal hypoglycemia, micropenis, delayed puberty
- MRI shows thin/absent pituitary stalk
133
131. What are the causes of delayed puberty with hypergonadotropic hypogonadism?
GONADS FAIL
G – Genetic syndromes
O – Ovarian/Testicular dysgenesis
N – No response to gonadotropins
A – Autoimmune destruction
D – Drugs and toxins
S – Surgical removal or trauma
F – Failure due to radiation
A – Aromatase deficiency
I – Infections
L – Lack of gonadal tissue
134
9. A child presents with short stature, delayed bone age, and low IGF-1. What is the diagnosis?
Diagnosis: Growth Hormone Deficiency
- Features: Short stature, delayed bone age, low IGF-1
- May have midline defects or neonatal hypoglycemia
135
11. What is the most common cause of central precocious puberty in girls?
Most common cause: Idiopathic (often hypothalamic GnRH activation)
- More common in girls than boys
- Requires MRI to exclude CNS pathology
136
72. What is the most common cause of delayed puberty in boys?
Most common cause: Constitutional delay of growth and puberty
- Normal variant, often familial
- Delayed bone age, low LH/FSH
137
71. What endocrine disorder is associated with delayed bone age and central precocious puberty?
Disorder: Primary hypothyroidism
- Delayed bone age due to growth suppression
- TSH may trigger gonadotropin release leading to CPP
138
149. What is the role of bone age in evaluating precocious puberty?
Bone age: Advanced bone age supports true precocious puberty
- Helps differentiate from benign variants
139
148. How is peripheral precocious puberty managed?
Management: Treat underlying cause (e.g., tumor, McCune-Albright)
- Hormone inhibitors like aromatase inhibitors or anti-androgens may help
140
147. What is the treatment for central precocious puberty?
Treatment: GnRH analogs (e.g., leuprolide)
- Suppresses pituitary-gonadal axis
- Delays progression and preserves height
141
28. A child with delayed puberty and anosmia. What other system should be evaluated?
System: Olfactory (anosmia is key to Kallmann syndrome)
- Also assess for midline defects, renal anomalies
142
15. What is the most common cause of peripheral precocious puberty in girls?
Most common cause: Functional ovarian cyst or McCune-Albright Syndrome
- Can cause estrogen production independent of GnRH
143
144. A boy presents with early puberty, café-au-lait spots, and bone lesions. What is the diagnosis?
Diagnosis: McCune-Albright Syndrome
- Triad: Precocious puberty, café-au-lait spots, fibrous dysplasia
144
146. What are the red flags for pathologic precocious puberty?
Red flags: Rapid progression, CNS signs, age <6 years (girls), age <9 years (boys), neurological symptoms
145
142. What ovarian tumors are associated with precocious puberty?
Tumors: Granulosa cell tumors (secrete estrogen)
- May present with isosexual precocity and ovarian mass
146
132. What are the causes of delayed puberty with hypogonadotropic hypogonadism?
Causes: Kallmann syndrome, chronic illness, hypothyroidism, pituitary tumors, constitutional delay
- Low/normal FSH/LH
147
134. What is the first investigation in a child with delayed puberty?
First investigation: Bone age X-ray
- Assesses skeletal maturity and predicts pubertal potential
148
135. How is bone age used in evaluating delayed puberty?
Bone age: Delayed → constitutional delay or chronic illness
- Normal → familial short stature
- Advanced → precocious puberty
149
16. A child with precocious puberty, café-au-lait spots, and fibrous dysplasia of bone. What is the diagnosis?
Diagnosis: McCune-Albright Syndrome
- Triad: Fibrous dysplasia, café-au-lait spots, precocious puberty
- GnRH-independent
150
137. A 15-year-old boy with no testicular enlargement, delayed bone age, and family history of late puberty. Diagnosis?
Diagnosis: Constitutional delay of puberty
- Normal variant, strong family history
- Reassure and monitor
151
18. A teenage boy with short stature, delayed puberty, anosmia, and low LH/FSH. What is the diagnosis?
Diagnosis: Kallmann Syndrome
- Hypogonadotropic hypogonadism with anosmia
- Low LH, FSH, testosterone
- Delayed puberty
152
138. What is the treatment for constitutional delay of puberty?
Treatment: Observation or short course of low-dose sex steroids
- Testosterone in boys, estrogen in girls to initiate puberty
153
139. What is the role of MRI in evaluating delayed puberty?
MRI: Indicated in central hypogonadism or precocious puberty
- Rules out hypothalamic/pituitary lesions
154
140. What hormones are used to differentiate central from peripheral precocious puberty?
Hormones: LH, FSH, estradiol/testosterone
- Central (GnRH-dependent): Elevated LH/FSH
- Peripheral: Low LH/FSH, high sex steroids
155
17. What are the hormone levels in constitutional delay of puberty?
Hormones: Low/normal LH and FSH, delayed bone age
- Diagnosis of exclusion
- Normal puberty expected later
156
193. What is the role of inhibin B in male gonadal function assessment?
Inhibin B: Secreted by Sertoli cells, reflects spermatogenic activity
- Low in primary testicular failure
157
195. What fertility preservation options exist for pediatric oncology patients?
Options: Oocyte or ovarian tissue cryopreservation (females), sperm banking or testicular biopsy (males)
- Depends on age/puberty status
158
191. What is the role of AMH (anti-Müllerian hormone) in pediatric endocrinology?
AMH: Secreted by Sertoli cells; inhibits Müllerian duct development
- Marker of testicular presence/function in DSD evaluation
159
192. What conditions are associated with elevated AMH levels in children?
Elevated AMH: Persistent Müllerian duct syndrome, granulosa cell tumors, some forms of precocious puberty
160
184. What is the most sensitive test for central hypothyroidism?
Test: Low free T4 with inappropriately normal or low TSH
- TSH alone may be misleading
161
177. What lab findings are seen in hypoparathyroidism?
Findings: Low calcium, high phosphate, low PTH
- Causes: Autoimmune, genetic (e.g., DiGeorge), post-surgical
162
172. How does hypothyroidism affect school performance in children?
Hypothyroidism causes poor concentration, fatigue, and slow growth
- May present as academic decline
- Screen with TSH and T4
163
1. A newborn is lethargic, has a hoarse cry, macroglossia, and prolonged jaundice. TSH is elevated. What is the most likely diagnosis?
Diagnosis: Congenital Hypothyroidism
- Features: Lethargy, macroglossia, prolonged jaundice
- Labs: Elevated TSH, low T4
- Treat early to prevent intellectual disability
164
115. What are the biochemical features of medullary thyroid carcinoma?
Biochemical features: Elevated calcitonin, elevated CEA
- No elevation in TSH or T4
- Confirm with biopsy
165
87. What is the emergency management of thyroid storm?
Management: Beta-blocker (propranolol), antithyroid drugs (methimazole), iodine, corticosteroids
- ICU support and fluids
166
86. What are the signs of thyroid storm in children?
Signs: Fever, tachycardia, hypertension, delirium, vomiting, diarrhea
- May be precipitated by surgery, infection, trauma
167
85. What are the causes of secondary hypothyroidism?
Causes: Pituitary or hypothalamic dysfunction
- Tumors, trauma, irradiation, infiltrative disease
- Labs: Low TSH and low T4
168
84. A child has goiter, high TSH, and normal T4. What is the diagnosis?
Diagnosis: Subclinical hypothyroidism
- High TSH, normal free T4
- Often autoimmune (Hashimoto)
- Monitor or treat if symptomatic
169
83. How is treatment response monitored in congenital hypothyroidism?
Monitoring: TSH and free T4 every 2 weeks initially, then every 1–3 months
- Goal: Normalize T4 quickly, then adjust for TSH
170
82. What is the dose of levothyroxine in congenital hypothyroidism?
Dose: 10–15 mcg/kg/day
- Start as early as possible (within first 2 weeks of life)
- Reassess TSH and T4 regularly
171
81. What is the first-line treatment for hypothyroidism in children?
First-line: Levothyroxine (oral T4)
- Lifelong therapy in permanent cases
- Dose based on age and weight
172
77. What is the best screening test for thyroid dysfunction in Down syndrome?
Best test: TSH (with reflex free T4 if abnormal)
- Annual screening recommended due to high prevalence of hypothyroidism
173
54. What condition is characterized by obesity, delayed growth, and central hypothyroidism due to hypothalamic damage?
Condition: Hypothalamic Obesity Syndrome
- Can follow surgery or damage to hypothalamus (e.g., craniopharyngioma)
- Features: Obesity, hyperphagia, low GH/TSH
174
38. How can FHH be differentiated from primary hyperparathyroidism?
Differentiate using urinary calcium/creatinine ratio
- FHH has low urinary calcium (<0.01)
- Primary hyperparathyroidism has high urinary calcium
175
35. What physical features are associated with pseudohypoparathyroidism type 1a?
Physical features: Short stature, obesity, round face, brachydactyly, subcutaneous ossifications
- Known as Albright hereditary osteodystrophy
176
34. What are the biochemical features of pseudohypoparathyroidism?
Features: Low calcium, high phosphate, high PTH
- End-organ resistance to PTH
- Often presents in childhood with seizures
177
5. What is the first-line treatment for Graves' disease in children?
First-line treatment: Methimazole
- Safer than PTU in children
- Beta-blockers for symptomatic relief
178
4. What are the typical lab findings in primary hypothyroidism?
Lab findings: High TSH, low free T4
- May also have elevated cholesterol and CK
- Delayed bone age on X-ray
179
3. What is the most common cause of congenital hypothyroidism?
Most common cause: Thyroid dysgenesis
- Includes agenesis, hypoplasia, or ectopia
- Detected on newborn screening
180
88. What are the red flag features of thyroid nodules in children?
Red flags: Firm, fixed nodule, rapid growth, lymphadenopathy, hoarseness, history of radiation
- Requires urgent evaluation
181
116. What is the role of calcitonin in medullary thyroid carcinoma?
Calcitonin: Marker of disease activity and recurrence
- Monitored postoperatively in MTC patients
182
89. What is the most common type of thyroid cancer in children?
Most common: Papillary thyroid carcinoma
- Excellent prognosis
- Often associated with radiation exposure
183
91. What are the causes of congenital hypothyroidism?
Causes: Thyroid dysgenesis (most common), dyshormonogenesis, maternal antibodies, iodine deficiency or excess
184
113. What is the screening protocol for medullary thyroid carcinoma in MEN2?
Protocol: Genetic testing for RET mutation in infancy
- Prophylactic thyroidectomy based on risk category and calcitonin levels
185
108. What genetic condition is associated with neonatal severe hyperparathyroidism?
Condition: Familial hypocalciuric hypercalcemia (FHH)
- Neonatal form can cause severe hypercalcemia, failure to thrive
- CASR gene mutation
186
105. What are the causes of secondary hyperparathyroidism?
Causes: Vitamin D deficiency, chronic kidney disease, malabsorption
- Stimulates PTH to maintain calcium levels
187
104. How is secondary hyperparathyroidism differentiated from primary?
Primary: High calcium, high PTH
- Secondary: Low/normal calcium, high PTH (due to chronic hypocalcemia or vitamin D deficiency)
188
103. What are the lab findings in primary hyperparathyroidism?
Labs: High calcium, high PTH, low phosphate, high urinary calcium
- Confirmed with PTH assay
189
102. What is the most common cause of primary hyperparathyroidism in children?
Most common cause: Parathyroid adenoma
- Other causes: Hyperplasia, carcinoma (very rare)
190
101. What are the clinical features of hyperparathyroidism in children?
Features: Bone pain, fractures, nephrolithiasis, abdominal pain, polyuria, constipation, weakness
- Rare in children
191
99. What imaging modality is useful in evaluating congenital hypothyroidism?
Imaging: Thyroid scintigraphy (technetium or iodine scan)
- Identifies ectopic, absent, or hypoplastic thyroid
192
98. What is the difference between Hashimoto thyroiditis and Graves' disease on labs?
Hashimoto: High TSH, low T4, positive TPO Ab
- Graves: Low TSH, high T4/T3, positive TSH receptor antibodies
193
97. What is the typical antibody pattern in Hashimoto thyroiditis?
Antibodies: Anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin
- May be positive years before symptoms
194
96. What is the most common cause of acquired hypothyroidism in children?
Most common cause: Hashimoto thyroiditis
- Autoimmune thyroiditis
- Presents with goiter and fatigue
195
95. What is the typical TSH response to primary hypothyroidism?
Response: Elevated TSH
- Due to loss of negative feedback from low T4
- Hallmark of primary hypothyroidism
196
94. A neonate has low T4 and low TSH. What is the likely cause?
Likely cause: Central (secondary) hypothyroidism
- Pituitary/hypothalamic cause
- Low TSH fails to stimulate T4 production
197
93. What are the effects of untreated congenital hypothyroidism?
Effects: Intellectual disability, growth failure, deafness
- Prevented by early treatment with levothyroxine
198
92. What are the clinical signs of hypothyroidism in infants?
Signs: Lethargy, hoarse cry, macroglossia, umbilical hernia, prolonged jaundice, constipation
199
90. What are the risk factors for thyroid cancer in children?
Risk factors: Prior neck irradiation, family history, genetic syndromes (e.g., MEN2), autoimmune thyroiditis
200
100. What is the prognosis of early-treated congenital hypothyroidism?
Prognosis: Excellent if treated early (before 2–3 weeks)
- Normal growth and neurodevelopment achievable
