LATEST PEDIATRIC ENDOCRINOLOGY
CERTIFICATION EXAM OFFERED BY
AMERICAN BOARD OF PEDIATRICS |
COMPLETE EXAM Q&A WITH RATIONALES
1. A 7-year-old girl presents with a 6-month history of
progressive fatigue, cold intolerance, constipation,
and weight gain. On examination, she has dry skin,
bradycardia (HR 60 bpm), and a palpable goiter. TSH
is 45 mIU/mL (normal 0.5-5.0), free T4 is low. Anti-
thyroperoxidase (TPO) antibodies are elevated. What
is the most likely diagnosis?
A) Hashimoto thyroiditis (autoimmune
hypothyroidism)
B) Subacute thyroiditis (de Quervain)
C) Central hypothyroidism (pituitary)
D) Euthyroid sick syndrome
Correct answer: A
Rationale: Hashimoto thyroiditis is the most common
cause of acquired hypothyroidism in children. Anti-
TPO antibodies are positive. Central hypothyroidism
(C) would have low TSH. Subacute thyroiditis (B)
presents with painful goiter and transient
hyperthyroidism.
,2. A 10-year-old boy with type 1 diabetes (diagnosed
at age 7) has a hemoglobin A1c (HbA1c) of 10.5%
(target <7.5%). He reports frequent nocturnal
hypoglycemia (glucose <50 mg/dL). He is on insulin
glargine (Lantus) once daily and insulin lispro
(Humalog) before meals. What is the most
appropriate insulin adjustment to reduce nocturnal
hypoglycemia?
A) Decrease evening glargine dose by 10-20%
B) Increase evening glargine dose (to improve
morning glucose)
C) Add a bedtime snack (milk and crackers)
D) Switch to insulin pump therapy
Correct answer: A
Rationale: Nocturnal hypoglycemia in a child on
basal-bolus insulin is often due to excessive basal
insulin (glargine). Reduce evening glargine dose by
10-20%. Bedtime snack (C) may help but does not
address the cause.
3. A 15-year-old girl presents with secondary
amenorrhea (no period for 6 months). She is a
competitive gymnast with a body mass index (BMI) of
16.5 kg/m². She denies binge eating or purging.
,Physical examination reveals bradycardia (HR 50
bpm) and lanugo hair. Laboratory: estradiol low, FSH
low, LH low (hypogonadotropic hypogonadism). What
is the most likely diagnosis?
A) Functional hypothalamic amenorrhea (FHA) due to
energy deficiency
B) Polycystic ovary syndrome (PCOS)
C) Premature ovarian insufficiency (POI)
D) Hyperprolactinemia (pituitary adenoma)
Correct answer: A
Rationale: FHA is common in athletes and low-weight
individuals (eating disorders). Low gonadotropins
(hypogonadotropic) are due to suppression of GnRH.
PCOS (B) would have elevated LH and
hyperandrogenism. POI (C) has elevated FSH.
4. A 5-year-old girl presents with a 3-month history of
rapid growth, acanthosis nigricans, and precocious
breast development (Tanner stage 3). Bone age is
advanced (8 years). Pelvic ultrasound shows
enlarged ovaries with multiple cysts. Laboratory:
estradiol elevated, LH elevated (prepubertal <0.3,
now 3.5 mIU/mL), FSH normal. What is the most likely
diagnosis?
, A) Central precocious puberty (GnRH-dependent,
idiopathic)
B) McCune-Albright syndrome (GnRH-independent)
C) Ovarian tumor (granulosa cell)
D) Congenital adrenal hyperplasia (CAH) (21-
hydroxylase deficiency)
Correct answer: A
Rationale: Central precocious puberty (GnRH-
dependent) is characterized by LH >0.3 mIU/mL and a
pubertal response to GnRH stimulation test. McCune-
Albright (B) is GnRH-independent (suppressed
LH/FSH, café-au-lait spots, polyostotic fibrous
dysplasia).
5. A 12-year-old boy presents with a 1-year history of
fatigue, polyuria, polydipsia, and weight loss (10
pounds). Fasting glucose is 320 mg/dL, HbA1c is
12%. Autoantibodies: GAD65 positive, IA-2 positive.
C-peptide is low (0.3 ng/mL). What is the most likely
diagnosis?
A) Type 1 diabetes mellitus (autoimmune)
B) Type 2 diabetes mellitus (insulin resistance)
C) Maturity-onset diabetes of the young (MODY)
D) Neonatal diabetes (KCNJ11 mutation)
CERTIFICATION EXAM OFFERED BY
AMERICAN BOARD OF PEDIATRICS |
COMPLETE EXAM Q&A WITH RATIONALES
1. A 7-year-old girl presents with a 6-month history of
progressive fatigue, cold intolerance, constipation,
and weight gain. On examination, she has dry skin,
bradycardia (HR 60 bpm), and a palpable goiter. TSH
is 45 mIU/mL (normal 0.5-5.0), free T4 is low. Anti-
thyroperoxidase (TPO) antibodies are elevated. What
is the most likely diagnosis?
A) Hashimoto thyroiditis (autoimmune
hypothyroidism)
B) Subacute thyroiditis (de Quervain)
C) Central hypothyroidism (pituitary)
D) Euthyroid sick syndrome
Correct answer: A
Rationale: Hashimoto thyroiditis is the most common
cause of acquired hypothyroidism in children. Anti-
TPO antibodies are positive. Central hypothyroidism
(C) would have low TSH. Subacute thyroiditis (B)
presents with painful goiter and transient
hyperthyroidism.
,2. A 10-year-old boy with type 1 diabetes (diagnosed
at age 7) has a hemoglobin A1c (HbA1c) of 10.5%
(target <7.5%). He reports frequent nocturnal
hypoglycemia (glucose <50 mg/dL). He is on insulin
glargine (Lantus) once daily and insulin lispro
(Humalog) before meals. What is the most
appropriate insulin adjustment to reduce nocturnal
hypoglycemia?
A) Decrease evening glargine dose by 10-20%
B) Increase evening glargine dose (to improve
morning glucose)
C) Add a bedtime snack (milk and crackers)
D) Switch to insulin pump therapy
Correct answer: A
Rationale: Nocturnal hypoglycemia in a child on
basal-bolus insulin is often due to excessive basal
insulin (glargine). Reduce evening glargine dose by
10-20%. Bedtime snack (C) may help but does not
address the cause.
3. A 15-year-old girl presents with secondary
amenorrhea (no period for 6 months). She is a
competitive gymnast with a body mass index (BMI) of
16.5 kg/m². She denies binge eating or purging.
,Physical examination reveals bradycardia (HR 50
bpm) and lanugo hair. Laboratory: estradiol low, FSH
low, LH low (hypogonadotropic hypogonadism). What
is the most likely diagnosis?
A) Functional hypothalamic amenorrhea (FHA) due to
energy deficiency
B) Polycystic ovary syndrome (PCOS)
C) Premature ovarian insufficiency (POI)
D) Hyperprolactinemia (pituitary adenoma)
Correct answer: A
Rationale: FHA is common in athletes and low-weight
individuals (eating disorders). Low gonadotropins
(hypogonadotropic) are due to suppression of GnRH.
PCOS (B) would have elevated LH and
hyperandrogenism. POI (C) has elevated FSH.
4. A 5-year-old girl presents with a 3-month history of
rapid growth, acanthosis nigricans, and precocious
breast development (Tanner stage 3). Bone age is
advanced (8 years). Pelvic ultrasound shows
enlarged ovaries with multiple cysts. Laboratory:
estradiol elevated, LH elevated (prepubertal <0.3,
now 3.5 mIU/mL), FSH normal. What is the most likely
diagnosis?
, A) Central precocious puberty (GnRH-dependent,
idiopathic)
B) McCune-Albright syndrome (GnRH-independent)
C) Ovarian tumor (granulosa cell)
D) Congenital adrenal hyperplasia (CAH) (21-
hydroxylase deficiency)
Correct answer: A
Rationale: Central precocious puberty (GnRH-
dependent) is characterized by LH >0.3 mIU/mL and a
pubertal response to GnRH stimulation test. McCune-
Albright (B) is GnRH-independent (suppressed
LH/FSH, café-au-lait spots, polyostotic fibrous
dysplasia).
5. A 12-year-old boy presents with a 1-year history of
fatigue, polyuria, polydipsia, and weight loss (10
pounds). Fasting glucose is 320 mg/dL, HbA1c is
12%. Autoantibodies: GAD65 positive, IA-2 positive.
C-peptide is low (0.3 ng/mL). What is the most likely
diagnosis?
A) Type 1 diabetes mellitus (autoimmune)
B) Type 2 diabetes mellitus (insulin resistance)
C) Maturity-onset diabetes of the young (MODY)
D) Neonatal diabetes (KCNJ11 mutation)
