Endocrine

Question 0

Growth rate that suggests no underlying pathologic disorder?

Answer 0

5 cm per year between age 3 and puberty

Question 1

Normal variant short stature versus pathologic short stature?

Answer 1

Height below 3rd percentile with normal growth velocity
versus
below 3rd percentile with sub optimal growth velocity (less than 2 inches per year)

Question 2

Height estimate?

Answer 2

(Mothers height + father’s height +/-5 inches)/2

+/-4

Question 3

Normal upper-to-lower body segment ratios?

Answer 3

Birth: 1.7
3 years: 1.3
>7: 1.0

Question 4

Types of normal variant short stature?

Answer 4

1. Familial – 2 SDs below mean but with normal bone age, normal onset of puberty, and minimal growth of 2 inches per year
2. Constitutional – 2 SDs below mean and minimal growth of 2 inches per year but with: delayed puberty in parents, delayed bone age, late onset puberty

Question 5

Proportionate versus disproportionate pathologic short stature?

Answer 5

Normal U/L ratio versus increased U/L ratio

Question 6

Causes of prenatal onset proportionate short stature? Postnatal onset proportionate short stature?

Answer 6

1. Environmental exposures (tobacco/alcohol in utero)
2. Chromosome disorders (down/Turner)
3. Genetic syndromes (Russell-silver, Prader-Willie)
4. Borrow infections in early pregnancy (CMV, rubella)
5. Malnutrition
6. Psychosocial (neglect, child abuse)
7. Organ system diseases (IBD, congenital heart disease, renal failure, cystic fibrosis, hypothyroid, GH deficiency, Cushing’s)

Question 7

Causes of disproportionate short stature?

Answer 7

1. Ricketts

2. Skeletal dysplasias

Question 8

Laboratory studies to conduct with pathologic short stature? Radiographic studies?

Answer 8

1. Common labs - CBC, ESR, T4, calcium, phosphorus, creatinine
2. IGF- indirect test for growth hormone
3. Chromosome analysis and girls (Turner)
4. Bone age (AP of left hand and wrist)
5. AP and lateral skull radiographs (for pituitary Island, craniopharyngioma)

Question 9

Ddx if bone age equals chronologic age?

If bone age <chronological age?

Answer 9

1. Familial short stature,
2. Intrauterine growth retardation
3. Turner
4. Skeletal dysplasia
5. Constitutional short stature
6. Hypothyroid
7. Hypercortisolisn
8. Growth Hormone deficiency
9. Chronic diseases

Question 10

Growth hormone deficiency – clinical features? Causes? Evaluation? Management?

Answer 10

1. Prolonged neonatal jaundice
2. Cherubic facies, central obesity
3. Microphallus, cryptorchidism
4. Hypoglycemia
5. Poor growth velocity
6. Single central maxillary incisors or cleft palate
7. Craniopharyngioma
8. CNS irradiation, vascular malformations
9. Autoimmune
10. MRI of head
11. IGF-1 levels, poor response to GH stimulation (glucagon, clonidine)

Daily subcutaneous injections of GH

Question 11

Sexual precocity associated with?

Answer 11

Obesity

Question 12

Precocious puberty? Causes?

Answer 12

Development before nine years

1. premature thelarche
2. Premature adrenarche
3. Isosexual precocious puberty or central precocious puberty
4. Peripheral precocious puberty or heterosexual gonadotropin-independent puberty

Question 13

Premature Thelarche – definition, epidemiology, etiology, work up/treatment?

Answer 13

Breast tissue only, without other sexual secondary sex characteristics (Normal growth pattern, no pubic hair)

Common and benign, usually begins the first two years of life

Premature activation of HPGA, resulting in the release of low levels of estrogen

No workout/treatment unless pubic hair or rapid growth

Question 14

Premature adrenarche – definition? Epidemiology? Classic presentation? Tx?

Answer 14

Early-onset pubic/axillary hair without development of breast/testing

More common in girls

Girl over 5 presents with pubic hair growth and a print order. No breast tissue/no clitorimegaly/normal growth

No Treatment

Question 15

Isosexual precocious puberty or central precocious puberty – Definition? Epidemiology? Clinical features? Causes?

Answer 15

Are the activation of the hypothalamus

Higher incidence in girls

breast/testes development, pubic hair, rapid growth

Idiopathic in girls
Organic in boys – get MRI

1 CNS causes- Hydrocephalus, infection, cerebral palsy, hamartomas, astrocytomas/gliomas
2. Hypothyroidism – unlike other causes, poor growth and delayed bone age

Question 16

Evaluation of a patient with suspected central precocious puberty?

Answer 16

1. FSH, LH, sex steroids should be elevated into pubertal range
2. GnRH stimulation test (measure LH/FSH response)
3. Head MRI in males

Question 17

Peripheral precocious puberty or heterosexual gonadotropin-independent puberty – definition? Features? Evaluation?

Answer 17

Precocious puberty that is independent of the HPGA (peripheral production of sex steroids and no increase in FSG/LH)

1. Boys – present with feminization or premature pubic hair – no increase in FSH so no testicular enlargement
2. Girls – virilization or breast development
3. Boys – serum FSH, LH, testosterone, B-HCG
4. Girls – serum FSH, LH, estradiol
5. CNS imaging

Question 18

Causes of peripheral precocious puberty?

Answer 18

Girls – adrenal tumors, virilizing ovarian tumors, feminizing ovarian tumors, nonclassical CAH, McCune-Albright syndrome

Boys – typically no teaticulat enlargement (no FSH): adrenal tumors, leydig cell tumors, nonclassical CAH, B-HCG tumors

Males with testicular enlargement:

1. McCune-Albright syndrome (bony changes, café au lait spots endocrinopathy)
2. Testicular toxicosis – testes enlarged but independent of HPGP
3. B-hCG secreting tumors – chest, pineal gland, gonad, hepatoblastoma (B-HCG cross reacts with LH receptors, stimulating leydig cells)

Question 19

Delayed puberty – definition? Classification? Evaluation?

Answer 19

No testicular enlargement by 14 or no breast tissue by each 13 or no menarche by age 14

1. Hypogonadotropic hypogonadism – inactivity of hypothalamus and pituitary gland, causing low hormones and flat GnRH stimulation test
2. Hypergonadotrophic hypogonadism – gonadal failure resulting in high FSH and LH with low testosterone/estradiol

CBC, ESR, T4, testosterone, estradiol, FSH, LH, prolactin level, bone age

Question 20

Causes of hypogonadotrophic hypogonadism?

Answer 20

1. Constitutional delay of puberty
2. Chronic disease
3. Hypopituitarism (brain tumors)
4. Primary hypothyroidism
5. Prolactinoma
6. Genetic syndromes (Kallmann syndrome, Prader-Willi, Lawrence-Moon-Biedl)

Question 21

Kallman syndrome?

Answer 21

Isolated gonadotropin deficiency with inability to smell

Question 22

Lawrence-Moon-Biedl syndrome?

Answer 22

Obesity, retinitis pigmentosa, hypogonadism, polysyndactyly

Question 23

Causes of hypergonadotrophic hypogonadism?

Answer 23

1. Chromosome – Kleinfelter (boys) for Turner/gonadal dysgenesis (girls)
2. Autoimmune (autoimmune oophoritis, Hashimoto’s, Addison’s)

Question 24

Male sex differentiation?

Answer 24

1. SRY gene differentiates testes 2. Testosterone from Leydig cells stimulates wolffian ducts 3. Anti-Mullerian hormone from Sertoli cells inhibits Mullerian structures 4. DHT from 5a-reductase produces external genitalia

Question 25

Causes of ambiguous genitalia in an undervirilized male?

Answer 25

1. Inborn error of testosterone synthesis (XY) 2. Mixed gonadal dysgenesis (XY mosaicism) 3. True hermaphroditism – The biggest genitalia with both ovarian and testicular gonadal tissues ( XX, XY) 4. Partial androgen insensitivity – defect in androgen receptor (XY)

Question 26

Causes of ambiguous genitalia in virilized female?

Answer 26

1. CAH called by 21-hydroxylase deficiency, 11 B-hydroxylase, 3V-hydroxysteroid dehydrogenase deficiency 2. Virilizing drug used by mother during pregnancy 3. Virilizing tumor in mother during pregnancy

Question 27

Patient with ambiguous genitalia and increased blood pressure? Decreased blood pressure?

Answer 27

CAH with 11 B hydroxylase deficiency; adrenal insufficiency

Question 28

Laboratory studies in patients with ambiguous genitalia?

Answer 28

1. Males – DHT, testosterone | 2. Females – electrolytes, testosterone, DHEA, 17 hydroxylase

Question 29

Primary adrenal insufficiency – due to? Clinical features? Examples?

Answer 29

Destruction of adrenal cortex or enzyme deficiency 1. Cortisol deficiency (anorexia, weakness, hyponatremia, hypotension, increased pigmentation) 2. Aldosterone deficiency (failure to thrive, salt craving, hyponatremia, hyperkalemia) Addison's disease, CAH, adrenoleukodystrophy

Question 30

Secondary adrenal insufficiency – due to? Clinical features? Examples?

Answer 30

Process that interviews with the release of CRH for ACTH 1. Normal serum potassium because no aldosterone deficiency 2. Cortisol deficiency Iatrogenic, Pituitary tumor, Craniopharyngioma, Langerhans cell histiocytosis

Question 31

Most common cause of ambiguous genitalia with no public gonads? Mechanism? Main deficiencies?

Answer 31

Congenital adrenal hyperplasia – enzyme deficiency leading to shunting to another pathway increasing androgen production 1. 21-hydroxylase deficiency (Mineralocorticoid +/- glucocorticoid deficiency) 2. 11B-hydroxylase deficiency (Hypertensive and hypokalemic) 3. 3B-hydroxysteroid deficiency (Salt wasting crisis, glucocorticoid deficiency, ambiguous genitalia)

Question 32

Management of patients with congenital adrenal hyperplasia?

Answer 32

1. Cortisone administration to depress ACTH levels 2. Mineralocorticoid replacement (fluorocortisone) 3. Monitor growth and development

Question 33

Adrenal insufficiency – causes? Evaluation? Management?

Answer 33

1. Steroid use 2. Addison's disease (autoimmune destruction) 3. Waterhouse-Fredrickson syndrome ACTH stimulation test Steroids and IV fluids

Question 34

Major causes of hypercortisolism? Diagnosis?

Answer 34

1. Iatrogenic 2. Cushing's syndrome (adrenal tumor) 3. Cushing disease (andenoma) 1. 24 hour urine cortisol 2. Overnight dexamethasone suppression test

Question 35

Cushing's versus obesity?

Answer 35

Growth Impairment and delayed bone age versus normal growth and advanced bone age

Question 36

Protracted cases of monilial vulvovaginitis associated with? Disease Also associated with?

Answer 36

Diabetes; enterovirus (Coxsackie) and rubella

Question 37

Somogyi phenomenon?

Answer 37

Evening dose of insulin is too high causing hypoglycemia resulting in increased release of epinephrine/quickly gone to cataract. Results in high blood glucose and ketones in the morning Treatment: lower the bedtime insulin

Question 38

Microvascular versus macrovascular complications of diabetes?

Answer 38

Retinopathy, nephropathy, neuropathy versus atherosclerosis, hypertension, heart disease, stroke

Question 39

Added effect of repleting potassium with potassium phosphate?

Answer 39

Increased 2,3-DPG, causing right shift to oxygen dissociation curve, making oxygen more available to tissues

Question 40

In DKA - target drop in glucose levels? Otherwise?

Answer 40

100 mg/dL/hr; cerebral edema

Question 41

Congenital hypothyroidism – causes? Clinical features? Management?

Answer 41

1. Thyroid dysgenesis (missing or atopic) 2. Thyroiddyshormonogenesis (error of thyroid hormone synthesis) 3. PTU during pregnancy (transient hypothyroidism of the Newmorn) 4. Maternal autoimmune thyroid disease (transient hypothyroidism if cross placenta) 1. Historical Sx: Prolonged jaundice and poor feeding 2. Current Sx: Lethargy and constipation 3. PE findings: large fontanelles, large tongue, umbilical hernia, myxedema, poor growth L-thyroxine

Question 42

Autoimmune polyendocrinopathies?

Answer 42

Hyperthyroid, vitiligo, alopecia, Addison's disease, diabetes

Question 43

Definition of hypocalcemia? Pseudohypocalcemia? Clinical Features? Causes in children? Tests? When to treat?

Answer 43

Serum calcium under 8 or ionized calcium under 2.5; low calcium due to low albumen (nephrotic syndrome) 1. Tetany (carpopedal spasm, laryngeal spasm, paresthesias) 2. Seizures (in pediatric patients) 1. ionized calcium and phosphorus 2. Serum magnesium 3. EKG for prolonged QT 4. PTH 5. Vitamin D 6. Radiographs for rickets Treat if calcium under 7.5 in newborns or under 8 in children

Question 44

Causes of hypocalcemia neonates under four? Over four? In children?

Answer 44

Under four days old: 1. prematurity, IUGR 2. Asphyxiation 3. hypoMg Older than four days: 1. hypoparathyroidism (mothers calcium suppresses fetus PTH) 2. DiGeorge 3. hyperphosphatemia (excessive intake from formula, uremia) Childhood: 1. Hypoparathyroidism (parathyroid failure from chromosomal, autoimmune or DiGeorge) If you will too. Pseudohypoparathyroidism (parathyroid resistance) 3. Hypomagnesium 4. Vitamin D deficiency

Question 45

Symptoms of pseudo-hypoparathyroidism?

Answer 45

Short stature, short metacarpals, developmental delay, elevated PTH

Question 46

Most common form of Rrckets in US? inheritance? Mechanism? Presentation? Labs? Treatment?

Answer 46

Familial hyperphosphatemia; X-linked dominant Renal tubular phosphorus leak Typical bowling of legs but never tetany Normal calcium but low phosphorus Phosphorus supplements and 1, 25 vitamin D analogues

Question 47

Oncogenic rickets? Consider when?

Answer 47

Phosphate-deficient form of rickets caused by tumor Patient presents with bone pain or myopathy

Question 48

Clinical features of rickets?

Answer 48

1. Occurs during first two years and adolescence 2. Affects wrists, knees, ribs 3. Legs become bowed when patient begins walking 4. Short stature 5. Richitic rosary and craniotabes 6. Frontal bossing and delayed suture closure

Question 49

Causes of central diabetes insipidus? Nephrogenic diabetes insipidus?

Answer 49

1. Autoimmune against ADH-producing cells 2. Trauma/ischemic brain injury 3. Hypothalamic tumor (Craniopharyngioma, glioma, germinoma) 4. Langerhans cell histiocytosis 5. Granulomatous disease 6. Vascular/genetic X linked recessive

Question 50

Evaluation and diagnosis of diabetes insipidus?

Answer 50

1. Hyponatremic dehydration 2. Move out if specific gravity greater than 1.018 3. Water deprivation test (no water then give ddAVP) 4. MRI of head (Check post pit) 5. Bone scan (for Langerhans histiocytosis)

Question 51

Neonatal hypoglycemia – transient vs Persistent? Causes of persistent hypoglycemia?

Answer 51

Less than versus greater than three days of hypoglycemia 1. Hyperinsulinism (islet cell hyperplasia, Beckwith-Wiedemann syndrome) 2. Defects in carbohydrate metabolism (glycogen storage disease, galactosemia) or amino acid metabolism (maple syrup urine disease, Tyrosinemia) 3. Hormone deficiencies (GH deficiency, cortisol deficiency)

Question 52

Hypoglycemia in infancy and childhood – Causes?

Answer 52

1. Ketotic hypoglycemia (most common form: inability to adapt to fasting state) 2. Ingestions (alcohol, oral hypoglycemic agents) 3. Inborn errors of metabolism 4. Hyperinsulinemia