paediatric oncology

Question 1

What is a retinoblastoma?

Answer 1

the most common ocular malignancy in children

Question 2

What age does retinoblastomas usually present?

Answer 2

18 months

Question 3

Aetiology of retinoblastoma

Answer 3

autosomal dominant condition caused by a loss of the tumour suppressor gene found on chromosome 13

Question 4

Presentation of retinoblastoma

Answer 4

absent red reflex - most common presenting symptom
strabismus
visual problems
bulging in one eye
red painful eye

Question 5

How are retinoblastomas diagnosed?

Answer 5

fundus photography
Fluorescein angiography
Ophthalmic USS- gold standard
MRI

Question 6

How are retinoblastomas treated?

Answer 6

initial management may involve- external beam radiation, chemotherapy and photocoagulation.

In unsuccessful may need enucleation (removal of the eye)

Question 7

Where do neuroblastomas arise from

Answer 7

the neural crest cells of the adrenal medulla or the sympathetic nervous system

Question 8

What is the median age of onset of neuroblastomas

Answer 8

20 months

Question 9

how do neuroblastomas present?

Answer 9

blueberry muffin rash - from seeding metastasis in the dermis.
abdominal mass
pallor
weight loss
bone pain and limp
hepatomegaly
paraplegia
proptosis
signs of increased catecholamine secretion -sweating, agitation

Question 10

What is the peak age of acute lymphoblastic leukaemia

Answer 10

2-3 years

Question 10

How are neuroblastomas diagnosed?

Answer 10

raised urinary vanillymandelic acid (VMA) and homovanillic acid (HVA) levels

USS or MRI

calcifications seen on X ray

Definitive test= MIBG scan (radioactive isotope injected and 2 scans taken 24 hours apart- iodine will stay in tumour)

Gold= biopsy

Question 10

What is the most common leukaemia in children

Answer 10

acute lymphoblastic leukaemia

Question 11

What leukaemias are common in children

Answer 11

acute lymphoblastic
acute myeloid
chronic myeloid leukaemia

Question 12

risk factors for leukaemia

Answer 12

radiation exposure during pregnancy
Down’s syndrome
Kleinfelter’s syndrome
Noonan syndrome
Fanconi anaemia

Question 13

pathophysiology of leukaemia

Answer 13

A cancer of the bone marrow- a genetic mutation leads to excessive production of a single blood cell
Leads to supression of all the other types of blood cells- pancytopenia

Question 14

How does leukaemia present?

Answer 14

general symptoms- anorexia, malaise, fever
bone marrow infiltration symptoms- pancytopenia (anaemia- lethargy, pallor; neutropenia- infection; thrombocytopenia - bruising, petechiae, epistaxis)
bone pain
reticulo-endothelial infiltration symptoms- hepatosplenomegaly, lymphadenopathy, superior mediastinal obstruction
symptoms of other organ infiltration - CNS, testes, mediastinal mass

Question 15

differentials for anaemia

Answer 15

viral infection
EBV infection
parvovirus
ITP,
aplastic anaemia

Question 16

how is leukaemia diagnosed

Answer 16

FBC- pancocytopenia
blood film- blast cells
bone marrow biopsy
lymph node biopsy

CT, chest x ray

Question 17

what is the most common malignant bone tumour in children

Answer 17

osteosarcoma

Question 18

two types of paediatric bone tumours

Answer 18

osteosarcoma and ewings sarcoma

Question 19

What is wilms tumour

Answer 19

a type of kidney tumour that typically affects children under 5

Question 20

what age group is most commonly affected by wilms tumours

Answer 20

children under 5- mean age is 3

Question 21

what genetic conditions are associated with wilms tumours (particularly if bilateral)

Answer 21

WAGR syndrome
Beckwith- Wiedemann syndrome
hemihypertrophy

Question 22

How does wilms tumour present?

Answer 22

abdominal mass
painless haematuria
flank pain = rare
anorexia
fever
weight loss

Question 23

Where does wilms tumour most commonly metastasise?

Answer 23

lung

Question 24

what genetic mutation is associated with wilms tumour

Answer 24

loss of function of the WT1 gene on chromosome 11

Question 25

Diagnosis of wilms tumour

Answer 25

1st line- USS abdo gold- biopsy

Question 26

How quickly should children presenting with an unexplained abdominal mass be reviewed in paediatrics

Answer 26

within 48 hours

Question 27

how is wilms tumour treated?

Answer 27

nephrectomy chemotherapy radiotherapy if advanced

Question 28

what is the prognosis of wilms tumour

Answer 28

80% cure

Question 29

what two bone tumours are most common in children?

Answer 29

osteosarcoma (most common) Ewings sarcoma

Question 30

what age group is typically affected by osteosarcomas?

Answer 30

aged 10-20

Question 31

what mutation is associated with osteosarcomas

Answer 31

a mutation in the Rb gene

Question 32

what conditions increase the risk of osteosarcomas?

Answer 32

Paget's disease radiotherapy Li-Fraumeni syndrome

Question 33

what mutation is associated with Ewing's sarcoma

Answer 33

t(11:22) translocation which results in a EWS-FLI1 gene product

Question 34

where in the bone do most osteosarcomas occur

Answer 34

in the metaphyseal region of long bones before closure of the epiphyseal plate

Question 35

what bones are most commonly affected in osteosarcomas?

Answer 35

femur - 40% Tibia- 20% Humerus - 10%

Question 36

what cells are osteosarcomas derived from

Answer 36

the primitive transformed cells of mesenchymal origin

Question 37

What bones do Ewing's sarcomas commonly effect?

Answer 37

pelvis and long bones

Question 38

What type of tumour is Ewing's sarcoma

Answer 38

neuroectodermal tumour

Question 39

How doe bone tumours in children present?

Answer 39

persistent bone pain- often worse at night and can wake them up from sleep May have bone swelling, a palpable mass and restricted joint movement

Question 40

How are bone tumours diagnosed

Answer 40

X ray- NICE recommends within 48 hours of child presenting with unexplained bone pain or swelling Bloods- raised ALP CT/MRI for staging Bone biopsy is definitive

Question 41

How does a osteosarcoma present on X ray

Answer 41

Codman triangle and a 'sunburst' pattern May show a poorly defined lesion in the bone with fluffy appearance

Question 42

How does Ewing's sarcoma present on X ray

Answer 42

onion skin appearance

Question 43

what is the most common type of brain tumour found in children ?

Answer 43

astrocytomas

Question 44

What is the most malignant cancer found in children

Answer 44

medulloblastomas

Question 45

what cells do meningiomas arise from

Answer 45

arachnoid cap cells of the meninges

Question 46

histopathology of medulloblastoma

Answer 46

small blue cells in a rosette pattern with many mitotic figures

Question 47

histopathology of astrocytomas

Answer 47

rosenthal fibres (corkscrew eosinophilic bundles)

Question 48

histopathology of meningiomas

Answer 48

spindle cells in concentric whorls and calcified psammoma bodies