ALL Flashcards
definition of ALL
malignancy of the bone marrow and blood
characterised by the proliferation of lymphblasts (primitive lymphoid cells)
maturation is arrested = uncontrolled proliferation of immature blast cells, with marrow failure and tissue infiltration
effect T and B cells
aetiology of ALL
lymphocytes are arrested at an early stage of development with varying cytogenic abnormalities, gene mutations and chromosome translocations
they undergo malignant transformation and proliferation
subsequent replacement of normal bone marrow elements = bone marrow failure and infiltration into other tissues
RF of ALL
environmental - radiation, viruses
genetic:
- Down’s syndrome,
- neurofibromatosis type 1,
- Fanconi’s anaemai,
- achondroplasia,
- ataxia telangiectasia,
- xeroderma pigmentosum,
- X-linked agammaglobinaemia,
- increased risk in siblings
epidemiology of ALL
most common malignancy of childhood
2-5yrs
second peak in the elderly
annual UK incience 1 in 70000
CNS involvement is common
2 causes of sx in ALL
sx of bone marrow failure
sx of organ inflitration
sx of bone marrow failure in ALL
anaemia - fatigue, dyspnora
bleeding - spontaneous bruising, bleeding gums, menorrhagia
opportunistic infections - bacterial, fungal, viral, protozoal
sx of organ infiltration of ALL
tender bones
enlarged LN
mediastinal compression (in T cell ALL)
meningeal involvement (headache, visual disturbance, nausea)
signs of bone marrow failure in ALL
pallor
bruising
bleeding
infection - fever, GI, skin, resp sx, mouth, perianal
- bacterial septicaemia
- zoster
- CMV
- measles
- candidiasis
- Pneumocystitis pneumonia
signs of organ infiltration in ALL
lymphadenopathy - superficial or mediastinal
hepatosplenomegaly
CN palsies
meningism
retinal haemorrhage or papilloedema on fundoscopy, leukaemic infiltration of the anterior chamber of the eye - mimics hypopyon
testicular swelling
Ix for ALL
blood:
- FBC - normochromic normocytic anaemia, low plt, variable WCC (usually high)
- high uric acid
- high LDH
- clotting screen
blood film - lymphoblasts
bone marrow aspirate/trephine biopsy - hypercelluler with >30% lymphoblasts
morphologic classification (French-American-British classification)
immunophenotyping - use Ab for cell surface ag eg CD20
cytogenic - karyotyping chromosomal abnormalities or translocations
cytochemistry - B- and T-lineage cells show up with APS stain adn acid phosphtase, respectively
LP and CSF analysis for CNS involvement
CXR - may show mediastinal lymphadenopathy, thymic enlargement, lytic bone lesions
CT - abdo lymphadenopathy
bone XR - mottled appearance with punched out eg skull caused by leaukaemic infiltration
morphologic classification of ALL
L1 - small lymphoblasts, scanty cytoplasm
L2 - larger, heterogenous lymphoblasts
L3 - large lymphoblasts with blue or vaculated cytoplasm
Immunological classification of ALL
surface markers used to classify it into:
- precurser B cell ALL
- T cell ALL
- B cell ALL
cytogenic classification of ALL
chromosomal analysis
abnormalities are detected in up to 85% - often translocations
useful for predicting prognosis and detecting recurrence
