Endocrine

Question 0

Deficiency of growth hormone with or without a deficiency of other pituitary hormones

Congenital or acquired

Clinical manifestations:

• of normal size and weight at birth
• atrophy of adrenal cortex, sensitivity to cold, absence of sweating

PE findings:

• tendency to hypoglycemia
• short and broad face, prominent frontal bone, depressed nasal bridge, underdeveloped mandible, short neck, high-pitched voice, well proportioned extremities but small hands and feet, delayed sexual maturity

LABORATORY findings

• diagnosis of classic type is suspected in cases of PROFOUND POSTNATAL GROWTH FAILURE (height >3 SD below the mean for age and gender)
• definitive diagnosis: ABSENT or LOW LEVELS OF GH in response to stimulation
• X-ray findings: destructive or space-occupying lesions: enlargement of the sella or erosions and calcifications within or above the sella turcica; delayed skeletal maturation

Answer 0

HYPOPITUITARISM

Question 1

Normal range for height

Over time, it starts falling off the height curve

Answer 1

Pathologic short stature

Question 2

Normal range for height

Normal final adult height is reached but the growth spurt and puberty are delayed

Answer 2

Constitutional short stature

Question 3

Stay parallel to the growth curve

Answer 3

Familial short stature

Question 4

Parallel to the growth curve but is much more marked

Answer 4

Prenatal short stature

Question 5

Guidelines for growth hormone treatment

Answer 5

hGH 0.18.-0.3 mg/kg/wk SC in 6-7 divided doses

Criteria for stopping tx: growth rate 14 yrs in girls and >16 years in boys

Question 6

Young persons with open epiphyses, overproduction of GH

Answer 6

Gigantism

Question 7

Persons with closed epiphyses

Answer 7

Acromegaly

Question 8

Cardinal clinical feature of gigantism

Answer 8

Longitudinal growth acceleration due to GH excess

Question 9

Coarse facial features, enlarged hands and feet, broad noses, enlarged tongue, visual field defects

Answer 9

Hyperpituitarism

Question 10

Diagnosis:
Serum somatomedin C (IGF-1) is uniformly increased in untreated cases
- more precise and cost-effective than serum GH because GH levels fluctuate and have short serum half-life (22 minutes)

Answer 10

Hyperpituitarism

Question 11

Management of Hyperpituitarism

Answer 11

• if with well-circumscribed pituitary adenomas: transsphenoidal surgery (complete removal of the tumor)
• pituitary radiation and medical therapy
• somatostatin analog (Octreotide)

Question 12

Cardinal features of diabetes insipidus

Answer 12

Polyuria and polydipsia

Question 13

2 types of diabetes insipidus

Answer 13

1. Vasopressin deficiency (central DI)

2. Vasopressin insensitivity (nephrogenic DI)

Question 14

Pathogenesis of DIABETES INSIPIDUS

Answer 14

As plasma osmolality increases, pat it becomes thirsty and drinks fluids

Plasma is diluted before it reaches the higher set level to stimulate ADH release

Initiates cycle of polyuria and polydipsia

Question 15

Congenital, trauma, tumors, autoimmune, infection, drugs (ethanol, phenytoin, etc)

Management:

• Fluid therapy
• Long-acting vasopressin analog dDAVP

Answer 15

Central diabetes insipidus

Question 16

Congenital (more severe), hypercalcemia, hypokalemia, renal disease (PCKD, CRF), drugs (lithium, amophotericin, rifampicin, etc)

Management:

• Treat underlying disorder
• thiazides (decrease urine flow to DCT, induce formation of functional receptors)

Answer 16

Nephrogenic diabetes insipidus

Question 17

What the hormone involved in Diabetes insipidus and what is its role?

Answer 17

VASOPRESSIN
- secreted from the posterior pituitary

Principal regulator of toxicity

Has both anitdiuretic and vascular pressor activity

Synthesized in the paracentricular and supraoptic nuclei of the hypothalamus

Question 18

Onset of secondary sexual characteristics before 8 years old in girls and 9 years old in boys

Answer 18

Precocious puberty

Question 19

Conditions causing precocious puberty

Answer 19

1. Gonadotropin-dependent puberty (true precocious puberty) - increased sex hormone secretion
2. Idiopathic
3. Brain tumors, severe head trauma, hydrocephalus
4. Prolonged and untreated hypothyroidism
5. Ovarian tumors

Question 20

Breast development in the first 2 years of life, regress after 2 years and rarely progressive

Answer 20

Premature thelarche

Question 21

Pubic hair, early maturational event of adrenal androgen production

Answer 21

Premature adrenarche

Question 22

Pertinent lab findings:
- Immunometric assay for LH (serum) - serial blood samples obtained during sleep and shows pulsatile LH secretion

• pelvic ultrasound - progressive enlargement of the ovaries and uterus
• Cranial CT scan/cranial MRI - physiologic enlargement of the pituitary gland; pedunculated mass attached to the tuber cinereum of the floor of the 3rd ventricle

Answer 22

Precocious puberty

Question 23

Treatment of precocious puberty

Answer 23

Leuprolide acetate -0.25-0.3mg/kg IM once every 4 weeks (true precocious puberty)

If treatment is effective, serum sex hormones decrease to prepubertal levels (testosterone <1 IU/L