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what fraction of childhood cases does leukaemia account for?
what are the 3 important causative factors in childhood cancer?
what is the gene defect in retinoblastoma?
chromosome 13 deletion of tumour suppressor gene
what is the gene defect in Li-Fraumeni?
what is the inheritance of Li-Fraumeni?
which cancers are people with Li-Fraumeni at risk of getting?
- sarcoma - soft tissue & bone
- adrenal cortical
what is the genetic defect with ataxia telangiectasia?
DNA repair defect
what is the gene defect assoc with downs?
which are the 2 main infections that are associated with malignancy?
- EBV: disruption of c-myc oncogene on chromosome 8 leading to malignant change eg Burkitt's lymphoma
- HIV: lymphoma
name an environmental risk factor for childhood cancers?
previous treatment of malignancy in a child
how do lymphomas usually present?
- constitutional symptoms
- weight loss
- night sweats
if there is a localised mass in the abdomen, which 2 cancers could that be?
- wilms tumour (nephroblastoma)
- neuroblastoma (most common extracranial solid cancer in childhood)
if there is a localised mass in the thorax, what cancer could that be?
non hodgkins lymphoma
if there is a localised mass in a soft tissue, what cancer could that be?
what cancer causes LN enlargement?
what cancer causes symptoms of bone marrow failure?
which 2 cancers can cause bone pain?
how does a primary CNS tumour present?
signs of raised ICP
what are the 5 main long term problems in survivors of childhood cancer?
- secondary tumours
- reduced fertility: from alkylating chemotherapy
- cognitive/psychosocial difficulties: methotrexate, school absence
- reduced growth and endocrine problems: irradiated glands
- auditory: platinum drugs
- cardiac: doxorubicin
what is the most common malignancy of childhood?
how do you characterise leukaemia?
proliferation of immature white cells
what is the onset of leukaemia?
what are the signs/symptoms of acute leukaemia? what causes them?
- infiltration of bone marrow/other organs with leukaemia blast cells
- anaemia: pallor & malaise
- thrombocytopenia: purpura, easy bruising, epistaxis
- neutropenia: infection
- reticuloendothelial cell infiltration: hepatosplenomegaly, lymphadenopathy
- expansion of marrow cavity: bone pain
- general: malaise, anorexia
how do you confirm the diagnosis of leukaemia?
bone marrow aspiration
what % of leukaemias are ALL?
what is the peak age for incidence of ALL?
between 3-6 years old
is ALL more in boys or girls?
how is ALL classified?
according to cell surface antigens = immunophenotype
what are the 3 immunophenotypes of ALL?
- non-T, non-B cell ALL: 80% are mostly early B cell clone
- T cell ALL: 15%
- B cell aLL: 1%
what are the 3 main prognostic factors taken into consideration for ALL and what is poor?
- age, WBC, lineage
- age: < 1yr
- WBC > 50
- lineage: T cell or B cell
which children get T cell ALL?
older children and teenagers
what are 2 features of T cell ALL?
- high peripheral WCC
- mediastinal mass
what % of ALL can be cured?
which cell type of ALL have the best prognosis?
- null cell (common)
- ie non-T, non-B cell
what % of children with ALL go into remission? and what % survive beyond 5 years?
which 3 ares of the body can relapses occur?
if there is a relapse of leukaemia, what needs to be done?
- high dose chemo
- total body irradiation
- BM transplant
why do boys need longer treatment than girls?
as relapses can occur in their testes
what has a worse prognosis ALL or AML?
AML and has more intensive treatment
what are 80% of AML cases associated with?
what is the tumour marker for neuroblastoma?
- what is the tumour marker for germ cell tumour/liver tumour?
- which oncogene is associated with poor prognosis in neuroblastoma?
- which 2 chromosomes are translocated in Ewings sarcoma?
- 11 and 12
before treatment of ALL is started, what needs to be ensured?
- anaemia is corrected with blood transfusion
- risk of bleeding minimised with platelet infusion
- hydration/allopurinol to protect renal function against effects of rapid cell lysis
what does remission mean?
eradication of the leukaemic blasts and restoration of normal marrow function
why are blocks of intensification chemotherapy given? give one adv and one disadv
- to consolidate remission
- they improve cure rates but at expense of increased toxicity
what is given for CNS protection? why?
- intrathecal methotrexate
- because systemic treatment of cytotoxic drugs poorly penetrate into CNS
how many years is maintenance chemotherapy continued for in boys and girls?
- boys 3 years (as testes involvement)
- girls 2 years
what prophylaxis treatment is given during chemotherapy and why?
- to prevent PCP
what are the 6 main short term SE of chemotherapy?
- BM suppression: anaemia, low plt, low neutrophils
- immunosuppression: infection
- GI: anorexia, N+V, gut mucosal damage - leading to undernutrition
what is the specific SE with doxorubicin?
what are the 2 specific SE with cisplatin?
what are the 2 SE of cyclophosphamide?
what is the SE of vincristine?
which type of lymphoma is more common in childhood?
which type of lymphoma is more common in adolescence?
how do T cell malignancies usually present?
- as ALL or NHL
- both - mediastinal mass & BM infiltration
how do B cell malignancies more commonly present?
- as NHL
- localised lymph node disease usually head, neck, abdomen
how does abdominal lymphoma usually present?
- palpable mass
- intussusception if the ileum is involved
how does hodgkins lymphoma usually present?
painless lymphadenopathy - neck usually
how can you tell between benign lymphadenopathy and lymphoma?
LN are larger and firmer
can HL be cured even if disseminated?
yes, 60% can be cured
which age group is NHL more common in?
which age group is HL more common in?
what increases your risk of NHL?
immunocompromised eg HIV, SCID
what is the growth of NHL like?
aggressive, rapidly growing
what are the different ways NHL may present?
- peripheral LN enlargement: B cell
- intrathoracic mass: T cell
- mediastinal mass or pleural effusion
- abdominal mass: advanced B cell disease
- Gut of LN masses
what is the mainstay of Rx of lymphoma?
what extra Rx may be needed for abdominal tumours NHL?
what are the 2 complications of NHL in the acute setting?
- SVC syndrome: SOB, face or arm swelling, distended veins
- tumour lysis syndrome: occurs after Rx of cancer due to breakdown products of cancer cells eg high K, high phosphate (causing low calcium - tetany seizures), high uric acid - renal failure
which cell is HL characterised by?
Reed Sternberg cell
does HL affect f or m more?
how does HL usually present?
- painless cervical or supraclavicular lymphadenopathy
- systemic symptoms are uncommon
where does mets of HL occur?
how is HL diagnosed?
LN biopsy and histological examination
what aerate 4 subtypes of HL and how does this affect prognosis?
- lymphocyte predominance: best prognosis
- mixed cellularity
- nodular sclerosing: most common in children and adolescents
- lymphocyte deplete: worse prognosis
which subtype of HL has best prognosis?
which subtype of HL has worse prognosis?
which is most common subtype of HL in children?
what is Rx of HL?
- stage first by imaging chest mediastinum abdomen
- Rx with combo chemo except if localised disease - radiotherapy
what is overall prognosis of HL?
what is the 2nd most common form of childhood cancer?
what is the commonest solid tumour of childhood?
where are 60% of brain tumours in children located?
what are signs and symptoms of brain tumours DUE TO?
- increased ICP
- cerebellar dysfunction
what are the 3 main types of brain tumours?
- PNET - primitive neuroectodermal tumours (medulloblastoma)
where are high grade astrocytomas located?
where are low grade astrocytomas located?
what age do children get astrocytoma?
how do cerebellar astrocytomas present?
- headache and vomiting: due to obstructive hydrocephalus
- cerebellar: ATAXIA, nystagmus, incoordination
- eyes: diplopia, SQUINT due to CN6 palsy
how do supratentorial astrocytomas present?
- focal neurological signs
how do brainstem gliomas present?
- CN palsy
- pyramidal tract signs
what are worrying features of headache?
- especially worse when lying down
- worse first thing in morning - as due to high ICP
what are worrying features of vomiting?
- especially on waking in mornings
- no nausea assoc with it
what is the most common MALIGNANT brain tumour in childhood?
PNET - medulloblastoma
which gender and age does PNET occur in?
where do PNET arise and where do they invade?
- arise in MIDLINE
- invade 4th ventricle and cerebellar hemispheres
what is different about PNET tumours from the other brain tumours?
- they seed through the CNS
- 20% have spinal mets at diagnosis
what are the presenting features of PNET?
what is Rx of PNET?
- surgical removal
- whole CNS irradiation
what are 5yr survival rates of PNET?
where do craniopharyngiomas arise from?
remnant of Rathke's pouch
how do craniopharyngiomas present?
- visual field loss: compression of optic chasm
- pituitary dysfunction: growth failure, diabetes insipidus
which Ix do craniopharyngiomas show up on and why?
what is Rx of craniopharyngioma?
- surgical excision
- may need radiotherapy
what is prognosis and sequelae of craniopharyngioma?
- good prognosis
- sequelae: visual impairment, endocrine deficiency
what is neuroblastoma?
malignancy of NEURAL CREST CELLS
what do neural crest cells normally give rise to?
- paraspinal SYMPATHETIC ganglia
- adrenal medulla
what age children does neuroblastoma occur in?
what do clinical features of neuroblastoma depend on?
what is the most common mode of presentation of neuroblastoma?
- non tender abdominal mass
what are clinical features of neuroblastoma? top to toe
- eyes: opsoclonus myoclonus from immune response, unilateral proptosis due to mets to eye
- mediastinum: mass on CXR
- abdominal mass: firm, non tender
- GI: diarrhoea due to secretion of VIP
- liver: hepatomegaly
- systemic: pallor, weight loss
- bone pain: disseminated disease
which Ix can be used to help diagnose neuroblastoma?
raised urinary catecholamines - VMA
how do you do a confirmatory diagnosis?
MIBG radiolabelled tumour specific agent
what is Rx of neuroblastoma?
- surgical resection
what makes prognosis worse in neuroblastoma?
- older children
- metastatic disease
- overexpression of N-myc oncogene
what is the proper name for Wilms tumour?
what age does wilms present?
first 5 years
what is the most common clinical presentation of wilms?
- asymptomatic abdominal mass
- that does not cross the midline
why would you get abdominal pain in wilms?
haemorrhage into the tumour
what are the 2 causes of hypertension in wilms?
- compression of renal artery
- renin production by tumour cells
what are other features of a wilms apart from abdominal mass?
- abdominal pain if bleeding into tumour
- hypertension - compression of renal artery or renin production by tumour cells
what other abnormalities is Wilms associated with?
- hemihypertrophy - one side of body is larger than other
- GU tract abnormalities
- mental retardation
- aniridia - absence of iris
which cells does wilms tumour arise from?
embryonic renal cells
how do you make diagnosis of wilms?
- CT characteristic appearance: INTRINSIC renal mass with MIXED solid and cystic densities
where are the most common mets of Wilms?
what is Rx of wilms?
- surgical resection
- radio if advanced disease
what is prognosis of wilms?
good 80% cure rate if no mets
what age group and gender does bone tumours affect?
what are the 2 main types of bone tumours in children? which is most common?
- osteogenic sarcoma - most common
- ewing's sarcoma
what age group does osteosarcoma affect?
what age group does ewings sarcoma affect?
what part of the bone is osteosarcoma a tumour of?
- bone producing mesenchyme
- m:f 2:1
what is the usual presenting feature of osteosarcoma?
- local pain - persistent
where do most cases of osteosarcoma occur?
around knee joint - metaphysis of distal femur or proximal tibia
where do osteosarcoma metastasise to?
what does bone x-ray of osteosarcoma show?
- sunburst appearance as tumour breaks through the cortex and spicules of new bone are formed
what is Rx of osteosarcoma?
- surgery of primary AND metastatic deposits
- aggressive chemo to treat micromets
what is survival of osteosarcoma?
what is the origin of ewings - what type of tissue?
- undifferentiated sarcoma
- uncertain tissue of origin - bone and sometimes soft tissues
which 2 types of bones does ewing's most commonly affect?
- long bones - mid to proximal femur
- also flat bones - pelvis
what are the presenting features of ewing's?
what does XR of Ewing's look like?
- destructive lesion
- periosteal elevation
- OR soft tissue mass - onion skin appearance
where do Ewing's mets occur to?
lung and other bones
what is Rx of Ewing's?
- radiotherapy to primary tumour
- combo with chemotherapy for prevention or Rx of mets
what is the genetic abnormality in retinoblastoma and which chromosome?
- deletion of tumour suppressor gene
- chromosome 13
what % of retinoblastoma is bilateral?
bilateral in 40%
how does retinoblastoma present?
absent red reflex
what is the pattern of inheritance in Rb?
dominant but with incomplete penetrance
when do most cases of Rb present?
first 3 yrs