Endocrinology Flashcards
What is the first sign of puberty in a boy?
Testicular enlargement
What is the first sign of puberty in a girl?
Breast budding
The height acceleration peaks in girls is at which sexual maturation rating (SMR) stage?
Between stage 2 and 3 SMR
The height acceleration peaks in boys is at which SMR stage?
Between stage 4 and 5 SMR
How many years after breast development does menarche start?
2.5years (approximately)
A 5-year-old female, pubic hair, adult odor, no breast development, bone age is equal to chronological age, slightly increased dehydroepiandrosterone (DHEA) level, normal growth pattern for age
Premature adrenarche
A 2-year-old female with bilateral breast buds, unchanged for 1year, no growth acceleration
Benign premature thelarche
A 4-year-old female with new-onset bilateral breast enlargement, advanced bone age, and elevated luteinizing hormone (LH) and folliclestimulating hormone (FSH)
Central precocious puberty is very likely
A 4-year-old boy presents with an adult-size phallus, pubic and axillary hair, acne, well-defined muscle tone, prepubertal size testicles
Peripheral precocious puberty
A 4-year-old boy presents with an adult-size phallus, pubic and axillary hair, acne, well-defined muscle tone, pubertal size testicles, advanced bone age
Central precocious puberty
A 4-year old boy with new-onset adult body odor, recent growth acceleration, pubic and axillary hair, thinning of the scrotum, enlargement of both testicles. Elevated LH and FSH.What is the best study to establish the diagnosis?
Brain MRI
A 5-year-old girl with pubic hair, mild hyperpigmentation of skin folds, slightly enlarged clitoris
Simple virilizing CAH-21 OH deficiency
Second newborn screen positive for high 17-hydroxyprogesterone. What is the next best step?
Repeat 17-hydroxyprogesterone test
Newborn with proximal hypospadias (e.g., penoscrotal) and cryptorchidism
Ultrasonography for internal genitalia, karyotype, and serum electrolytes to screen for congenital adrenal hyperplasia
What is the best treatment of congenital adrenal hyperplasia?
Hydrocortisone and fludrocortisone
What is the treatment for a patient with congenital adrenal hyperplasia who presents with vomiting and low blood pressure?
IV hydrocortisone and IV fluid hydration
A 2-week-old male with failure to thrive, persistent vomiting, dehydration, acidosis
CAH 21-OH deficiency (pyloric stenosis is associated with metabolic alkalosis)
Ambiguous genitalia, nephropathy, Wilms tumor, renal failure by 3years of age
Denys–Drash syndrome
Female phenotype at birth with undifferentiated streak gonads, presence of vagina/fallopian tubes, at puberty no breast development/menstruation, development of gonadoblastoma is the highest risk
Swyer syndrome (XY pure gonadal dysgenesis)
Newborn with a small penis, bifid scrotum, urogenital sinus, blind vaginal pouch, testes are in the inguinal canal, raised as a female, virilization occurs at the time of puberty, enlargement of penis and scrotum, sperm formation, and normal adult height
5-alpha reductase deficiency (autosomal recessive)
Infant phenotypically female at birth, raised as female, vagina ends in a blind pouch, no uterus, no fallopian tubes, intra-abdominal testes, normal breast development, no menses, normal male adult height, testosterone level is normal
Androgen insensitivity syndrome; 46, XY (X-linked recessive disorder)
XY normal male phenotype, inguinal hernia, undescended testis, Müllerian structures found incidentally (uterus and fallopian tubes)
Persistent Müllerian duct syndrome
A 4-year-old with precocious puberty, large caféau-lait spots, skeletal fibrous dysplasia, and vaginal bleeding are associated with
McCune–Albright syndrome
A slow growth rate in the first 2years of life (
Constitutional growth delay
Short child, growth velocity is 5cm/year. Bone age is consistent with chronological age, father and mother are short
Genetic/familial short stature
A 4-year-old, height
Growth hormone deficiency
Common hormone deficiency associated with single maxillary central incisors, septo-optic dysplasia, cleft lip, cleft palate, and microphallus
Growth hormone deficiency
Normal length and weight by birth initially that drops by 1-year, conjugated hyperbilirubinemia, hypoglycemia, broad facies, and microphallus
Congenital growth hormone deficiency
Decreased levels of IGF-1 and IGF-BP3 are seen in which hormone deficiency?
Growth hormone deficiency
Normal growth hormone levels, height
Idiopathic short stature
How do you calculate the mid-parental height for a male?
[Mother height + Father height +13cm]/2
How do you calculate the mid-parental height for a female?
[Mother height + Father height—13cm]/2
Pseudotumor cerebri, slipped capital femoral epiphysis, and gynecomastia are the possible side effects of which hormonal therapy
Growth hormone
A 7-year-old boy with a progressive headache, vomiting without nausea, bitemporal hemianopsia, short stature, weight gain, and fatigue. What is the next best step?
Brain MRI (craniopharyngioma)
A 7-year-old boy, at birth, was large for gestational age, macrocephaly, a rapid growth rate in the first 3years of life; now presenting with cognitive deficiency, autistic behavior, attention deficit hyperactivity disorder (ADHD), large and protruded head, large hands and feet, hypotonia, clumsiness, advanced bone age
Cerebral gigantism (Soto syndrome)
Boy with hypoplasia of optic nerves, nystagmus, an absence of septum pellucidum, schizencephaly, seizures, hypopituitarism, presented with hypoglycemia, jaundice, and micropenis at birth
Septo-optic dysplasia (De Morsier syndrome)
A 17-year-old female, amenorrhea, headache, galactorrhea, visual field defect; the pregnancy test is negative, and serum prolactin is >200mg/ dL.MRI showed a pituitary mass of 15mm with encroachment on the optic chiasm
Prolactinoma (macroadenoma)
A 17-year-old boy, no signs of puberty, penis, and testicles are prepubertal, and anosmia
Kallmann syndrome (hypogonadotropic hypogonadism)
A 17-year-old male presents for a well visit. He has academic difficulty, gynecomastia, small firm testicles (
Klinefelter syndrome 47, XXY karyotype
A 16-year-old female, short stature (
Turner syndrome; 45, X karyotype
The most common cardiac defect associated with Turner syndrome
Bicuspid aortic valve
Newborn girl had cystic hygroma on fetal ultrasound, lymphedema of the feet, webbed neck, heart murmur, and horseshoe kidney
Turner syndrome; 45, X karyotype
A 5-year-old male, lymphedema of the feet at birth, short stature, webbed neck, strabismus, hearing loss, joint laxity, pulmonary stenosis, intellectual disability, normal karyotype
Noonan syndrome (mutations in the RASMAPK pathway)
Newborn screen of a 6-day-old boy showed abnormal thyroid-stimulating hormone (TSH) level of 230mIU/L (elevated TSH >40mIU/L). Physical examination is unremarkable. What is the next best step?
Obtain confirmatory TSH and free thyroxine now but initiate the treatment immediately, before the results of the confirmatory tests are available
What is the optimal care of neonates with congenital hypothyroidism?
Early diagnosis before age 10–13days and normalization of thyroid hormone blood levels by age 3weeks
The most common cause of congenital hypothyroidism
Thyroid dysgenesis
What is the treatment of congenital hypothyroidism and how should the treatment be given?
Levothyroxine tablet (initial dose is 10–15mcg/ kg/day) should be crushed and mixed with breast milk or formula (cannot be mixed with soy formula)
Low free T4, elevated TSH
Primary hypothyroidism
Low free T4, normal or low TSH
Central hypothyroidism
High free T4 and T3, low TSH
Hyperthyroidism (most common)
Normal or low free T4, high T3, low TSH
Hyperthyroidism (less common)
Normal T4, low T3, normal/low TSH, the patient has pneumonia
Euthyroid sick syndrome
Low total T4, normal free T4, normal TSH
Thyroxine-binding globulin deficiency (TBG), hypoproteinemia, e.g., malnutrition and nephrotic syndrome
A 11-year-old female with no growth for 2years, tired, constipated and “yellowish” skin
Hypothyroidism (likely Hashimoto)
Adolescent with thyroid enlargement, no symptoms, TSH and free T4 are within the reference range, positive antithyroid peroxidase (TPO)
Hashimoto thyroiditis
A 14-year-old girl, school troubles, getting in fights, appears to be on drugs because of red bulgy eyes and irritability
Graves disease (hyperthyroidism)
What is the best test to confirm the diagnosis of Graves disease?
Thyrotropin receptor-stimulating immunoglobulin (TSI)
A painful thyroid gland that started after viral infection associated with elevated ESR with an eventual return to normal thyroid function
De Quervain thyroiditis—initial hyperthyroid phase, then hypothyroid phase with eventual recovery
Newborn child with tachycardia, irritability, hypertension, mother with a history of Graves disease?
Neonatal thyrotoxicosis
The most common symptom of hyperthyroidism or Graves disease
Weakness/fatigue
The most common side effect of antithyroid drugs (e.g., methimazole)
Transient urticarial rash
The best diagnostic test for solitary thyroid nodule
Fine needle aspiration biopsy; US-guided
The most common thyroid cancer in pediatric patients
Well-differentiated thyroid (follicular/papillary) carcinoma
Medullary thyroid cancer, hyperparathyroidism, pheochromocytoma
Multiple endocrine neoplasia (MEN)-2A
Medullary thyroid cancer, pheochromocytoma, mucosal neuroma
MEN-2B
Low to normal serum Ca, low serum phosphate, high alkaline phosphatase, low 25-(OH) vitamin D, high parathyroid hormone (PTH)
Vitamin D deficiency (rickets)
Normal serum Ca, low serum phosphate, very high alkaline phosphatase, normal vitamin D, failure to thrive, hypotonia, delayed dentition
Hypophosphatemic rickets or X-linked hypophosphatemic rickets
What is the mode of inheritance of hypophosphatemic rickets?
X-linked dominant
High serum PTH, low serum Ca, high phosphate, short stature, stocky habitus, soft-tissue calcifications/ossifications, short fourth and fifth metacarpal bones
Albright hereditary osteodystrophy (pseudohypoparathyroidism type 1A)
Short stature with stocky body habitus, soft-tissue calcification/ossifications, short fourth and fifth metacarpals with normal PTH, normal calcium, and normal phosphate
Pseudopseudohypoparathyroidism—due to paternal mutation
Normal serum Ca, low serum phosphate, very high alkaline phosphatase, non-anion gap metabolic acidosis, developmental delay, cataracts, glaucoma
Oculocerebrorenal dystrophy (Lowe syndrome)
A 7-year-old with obesity, hyperphagia, small hands and feet, small penis, cryptorchidism, and cognitive deficiency
Prader–Willi syndrome
What is the chromosomal deletion of Prader–Willi syndrome?
Paternal chromosome 15q11-q13 deletion
Obesity, retinitis pigmentosa, hypogonadism, intellectual disability
Bardet–Biedl syndrome or Laurence–MoonBiedl syndrome
Adolescent female, obesity, acanthosis nigricans, HBA1c 6.9%, elevated testosterone and LH, hirsutism, no ovarian cysts noticed on ultrasonography
Polycystic ovary syndrome
Failure to thrive, microcephaly, intellectual disability, ptosis, strabismus, syndactyly, pyloric stenosis, and low-plasma cholesterol
Smith–Lemli–Opitz syndrome (autosomal recessive)
Polydipsia, hypernatremia, serum osmolarity >300mOSm/kg, urine osmolarity
Diabetes insipidus (DI)
Patient with meningitis on IV fluids, hyponatremia, hypo-osmolality, elevated blood pressure, inappropriately concentrated urine, and high urine sodium level
Syndrome of inappropriate antidiuretic hormone secretion (SIADH)
What is the best initial treatment for the patient with SIADH in the previous example?
Reduce IV fluid rate (fluid restriction)
A patient underwent neurosurgery for a brain tumor, develops dehydration, hyponatremia, high urine output, hypovolemia, low blood pressure, high urine Na
Cerebral salt wasting
Cerebral salt wasting is associated with which hormone is being elevated?
Atrial natriuretic peptide
What is the best treatment for a patient with cerebral salt wasting dehydration?
Isotonic fluid hydration
Patient with diabetes insipidus comes in for water deprivation test, after administration of DDAVP (desmopressin) the urine becomes concentrated
Central diabetes insipidus
Patient with diabetes insipidus comes in for water deprivation test, after administration of DDAVP there is no effect on urine concentration
Nephrogenic diabetes insipidus
Child with obesity, height 95th percentile for age
Cushing syndrome
A 7-year-old boy with a history of severe asthma, presents with a 3-day history of worsening nausea, abdominal pain, and vomiting, he was on a high dose of inhaled steroids for 1year. Lately, the child is not compliant with medications. What is the most likely cause of his symptoms?
Adrenal insufficiency
Child is presents with fatigue, nausea, weight loss, hypotension, volume depletion, and diffuse hyperpigmentation
Addison disease
Child with type 1 diabetes mellitus, well controlled, suddenly develops hypotension and shock
Addison disease
Best initial treatment for a patient with diabetic ketoacidosis within the first hour who presents with volume depletion, e.g., tachycardia, prolonged capillary refill time, and elevated blood urea nitrogen and creatinine
IV hydration: 10mL/kg of intravenous normal saline over 1h
The most common cause of death in children who have type 1 diabetes
Diabetic ketoacidosis (DKA)
What is the most common cause of recurrent DKA?
Insulin omission
The most common cause of death related to DKA in children
Cerebral edema
Adolescent female presents with recurrent vaginal candidiasis, BMI >97th percentile, hypertension, acanthosis nigricans. What is the next best step?
Fasting blood glucose level
Adolescent female presents with polyuria, polydipsia, BMI >97th percentile, hypertension, acanthosis nigricans; her blood glucose level is 200mg/dL, A1C is 7%. What is the best treatment?
Metformin
Adolescent female presents with polyuria, polydipsia, BMI >97th percentile, hypertension, acanthosis nigricans; her blood glucose level is 350mg/dL, A1C is 10%. What is the best initial treatment?
Insulin Blood glucose level ≥250mg/dL, A1C ≥8.5% insulin is the best initial treatment
What is the A1C goal recommended by the American Diabetes Association for all pediatric age-groups with type 1 diabetes mellitus?
A1C target
A 3-day-old infant, 10lbs at birth, jittery
Infant of a diabetic mother with hypocalcemia
A 9-year-old male with sweating, jitteriness, and tachycardia with sudden onset of symptoms
Hypoglycemic episode Treatment: 15g of carbohydrate
A 9-year-old male who has altered mental status glucose is noted to be 45mg/dl. Best treatment?
IM glucagon
An infant with a history of tetralogy of Fallot presents with jitteriness and muscle twitching that has been worsening over the past few days. Blood glucose level is 85mg/dL, and the calcium level is 7mg/dL.What is the most likely cause?
Hypoparathyroidism
A 5-day-old infant, small jaw, broad nose, tetralogy of Fallot, seizure
DiGeorge/velocardiofacial (VCF)
A 3-month-old male with elfin facies, supravalvular aortic stenosis, now with serum Ca of 12.2
Williams syndrome
A 4-day-old male with hypoglycemia, omphalocele, hemihypertrophy
Beckwith–Wiedemann syndrome
Which childhood tumor is associated with Beckwith–Wiedemann syndrome?
Wilms tumor
A 10lb plethoric neonate, requiring 15mg/kg/min dextrose infusion. The mother without gestational diabetes mellitus (DM)
Congenital hyperinsulinism
A 5-year-old male previously healthy with throat pain and loss of appetite for 2days, suddenly starts feeling dizzy, jittery, becomes unconscious in ER; the glucose level is 37mg/dL, high level of serum and urine ketone, undetectable serum insulin, elevated serum cortisol, and growth hormone. What is the most likely cause?
Ketotic hypoglycemia (treatment is IV dextrose)
An 18-month-old thin boy with mild fever overnight presents with loss of consciousness and hypoglycemia
Ketotic hypoglycemia (diagnosis of exclusion)
A 5-day-old male with a small phallus, jaundice, now with glucose of 45mg/dl and ketones in urine after 4h of fasting
Hypopituitarism (adrenocorticotropic hormone (ACTH), growth hormone (GH) deficiency)
A 6-year-old with nighttime headaches, height has fallen from 25th percentile to 5th percentile over 1year. Enuresis
Intracranial tumor in the region of the pituitary
An 18-month-old male, length, and weight “stalled” for 9months. Stools remarkably odorous
Celiac/malabsorption
What are the components of metabolic syndrome?
Impaired glucose Low HDL High triglycerides Elevated blood pressure Central obesity
