Heme/Onc

Question 1

How much iron should be in formula for normal BW infant for the first 9-12 months?

High-risk for iron deficiency infant?

Answer 1

6.5-13mg/L

13mg/L

Question 2

List 5 risk factors for iron-deficiency in a child under 2 years

Answer 2

1. Preterm delivery
2. Low socio-economic status
3. Maternal anemia or obesity
4. Early umbilical cord clamping
5. Prolonged bottle use
6. Chronic infection
7. Lead exposure
8. Low intake of iron-rich complementary foods
9. Living in an Indigenous community that may be challenged with poverty, food insecurity, high burden of H pylori or high consumption of cow’s milk/evaporated milk
10. Low birth weight (<2.5kg)
11. Male sex

Question 3

List 2 effective measures to reduce iron deficiency

Answer 3

1. Feed iron-rich complementary foods from 6mo
2. Delayed cord clamping
3. If formula feeding, provide iron fortified formula
4. Do not use cow’s milk as main milk source until 12mo (limit to 500mL/<20oz)

Question 4

Who should receive additional iron supplementation?

When should it start?

How much should they receive?

What duration of time?

Answer 4

Who:

• Predominantly breastfed infants (>50%)
• Low birth weight (<2.5kg)

When: starting at 2-3 weeks postnatal age

How much/how long?:

• <2kg: 2-3mg/kg/day x 1 year
• 2-2.5kg: 1-2mg/kg/day x 1 year

Question 5

What are the stages of iron deficiency anemia in terms of changes seen to laboratory tests?

Why do we treat?

How much supplementation?

For how long?

Answer 5

Stages (2 non-anemic, 1 anemic0

1. ↓ ferritin→ depleted iron stores
2. ↓ transferrin saturation→ decreased iron transport
3. ↓ hemoglobin → decreased production of hemoglobin

Why treat: Risk of permanent neurodevelopmental impairment

How much?: 2-6mg/kg/day divided doses

How long?: 3 months (then recheck ferritin/CBC)

Question 6

What are the types of Vitamin K deficiency of the newborn?

Answer 6

1. early onset (1^st 24 hours post-birth)
   * Associated with maternal medications that inhibit vit K activity, e.g. anti-epileptics
2. classic (DOL 2 to 7)
   * low intake of vit K
3. late onset (2 - 12 weeks and up to 6 months of age)

• associated with chronic malabsorption and low vit K intake
• Presents with ICH

Question 7

What are the categories of brain tumours and their presenting symptoms?

Answer 7

• General symptoms:
  
  • Headache
  • N/V (usually in the morning)
    
    • Due to vasodilation of cerebral vessels overnight so more cerebral blood volume = raised ICP
  • Macrocephaly in infants/toddlers
  • Irritability
  • Obstructive hydrocephalus (papilledema, vomiting, obtundation)
• Neurologic symptoms based on locations:
  
  • Supratentorial:
    
    • New seizure
    • Visual changes
    • Visual field defect = involvement of optic nerves or tracts
    • Diencephalic syndrome:
      
      • Severe emaciation and FTT in otherwise happy infant
      • From tumours in hypothalamus
  • Infratentorial:
    
    • Ataxia, gait abnormalities
    • Nystagmus, esp with cerebellar tumours
    • Parinaud syndrome:
      
      • Paralysis of up-gaze, pupils mid-dilated and poor reaction to light, convergence or retraction nystagmus and eyelid retraction
      • From pineal or dorsal midbrain tumours
      • Tumours compress the rostral interstitial nucelus of medial longitudinal fasciculus (riMLF) on mesencephalic tectum
    • Head tilt
    • Obstructive hydrocephalus
    • Resection of infratentorial tumours often leads to cerebellar mutism syndrome
      
      • After surgery, pts have mutism, irritability, ataxia, hypotonia lasting few weeks to 6 months, then period of dysarthria that usually self-resolves
      • Occurs in up to 24% of pts with infratentorial resections
        
        • Most common in medulloblastoma
  • Parasellar:
    
    • Endocrine dysfunction (under or overproduction of hormones)
    • Visual field defects from growth up into optic nerve
  • Spinal:
    
    • Weakness
    • Pain

Question 8

What are the definitions, symptoms and treatment for pituitary adenomas?

Answer 8

• Pituitary adenoma
  
  • Anterior pituitary gland tumor
  • Benign
  • Microadenoma is <1 cm, and macroadenoma is >1 cm diameter
  • Non-secreting tumors: 30%
    
    • Can be completely asymptomatic
    • May cause hypopituitarism from compression
  • Hormone-secreting tumors: 70%
    
    • Prolactinomas cause milk production and inhibit GnRH, resulting in diminished testicular/ovarian function
    • Gigantism/acromegaly from GH
    • Cushing disease from adrenocorticotropic hormone (ACTH)
    • Hyperthyroidism from TSH
• Treatment
  
  • No need to treat microadenoma if not symptomatic
  • Medical management of prolactinoma
    
    • Dopamine agonist: decreases size of adenoma and decreases prolactin
    • If prolactin levels do not normalize, proceed to surgical debulking

Question 9

What are the most common brain tumours?

Answer 9

• Low-grade gliomas
  
  • Most common brain tumor in children
  • Neuroepithelial cell of origin
  • Generally slow growing, but based on location, can cause significant symptoms
    
    • Pilocytic astrocytoma:
      
      • Infratentorial, usually arising in cerebellum
      • Most common glioma in children
    • Optic nerve gliomas:
      
      • Associated with NF1
    • Diffuse fibrillary astrocytomas
• Medulloblastomas
  
  • Most common malignant (high-grade) brain tumors in children
  • Embryonal cell of origin
  • Arise in cerebellum
  • Can be metastatic to bone marrow (bone marrow biopsy required as part of workup)