Leukaemia 2 Flashcards
What is a leukaemia and what are the types
haemopoietic cells lose their ability to differentiate/mature into the end cells, remaining as precursor cells (blasts)
> 20% blast cells
Acute lymphoblastic = build up of lymphoid blast cells
Acute myeloid = build up of myeloid blast cells
Chronic leukaemia = the haemopoietic cells proliferate and differentiate but are non-functioning
What are the causes of ALL
proliferation of lymphoblasts (primitive lymphoid cells) → replacement of normal marrow → bone marrow failure and infiltration into other tissues
If build-up of B lymphoblasts → B-ALL (C10, C19, C20 surface markers)
If build-up of T lymphoblasts → T-ALL (CD2-CD8)
What is the most common leukaemia in children
Acute lymphoblastic leukaemia (ALL) (80%)
85% are B-lineage, 5% T cell lineage
What are the causes of AML
proliferation of myeloblasts (primitive WBCs) → Replacement of normal bone marrow elements → bone marrow failure
Monoblast AML
Megakaryoblast AML
Erythroblast AML
What are the risk factors for ALL
Radiation
Viruses
Down’s syndrome
NF1
Fanconi’s anaemia
Achondroplasia
Xeroderma pigmentosum
Siblings with ALL
What are the symptoms of leukaemia
Bone marrow failure
- Anaemia: pallor, lethargy, SOB
- Thrombocytopenia: bleeding gums, bruising, menorrhagia
- Neutropenia: opportunistic, recurrent infection
Local infiltration
- Lymphadenopathy
- Splenomegaly
- Testes, CNS (Sanctuary sites where chemotherapy cannot reach easily)
- Bone pain
What are the signs of ALL on examination
Testicular swelling
Thymic swelling
Hepatosplenomegaly
Lymphadenopathy
Tender bones
Mediastinal compression
Cranial nerve palsies
Retinal haemorrhage or papilloedema, leukaemic infiltration of the anterior chamber of the eye
What are the signs of AML on examination
Gum swelling/hypertrophy
CNS involvement (headaches, nausea, diplopia)
Skin rashes
Rare: deposits of leukaemic blasts in the eye, tongue and bone (fractures)
What investigations should be done for leukaemia
FBC: anaemia, neutropenia, thrombocytopenia
Clotting studies
Blood film
Cytochemistry (B or T lineage)
Immunohistochemistry
CXR: enlarge thymus, mediastinal lymphadenopathy, lytic bone lesions
Bone marrow biopsy: >20% blasts
Lumbar puncture
Bone radiograph: mottled appearance, “punched out” lesions
What is tumour lysis syndrome
↑ potassium, LDH, phosphate, uric acid
What are the diagnostic features specific to ALL
Blood film: positive TdT staining
What are the diagnostic features specific to AML
Blood film: Auer rods (myeloperoxidase crystalloid)
Immunohistochemistry: Myeloblast granules positive for Sudan Black staining
What is the management for leukaemia
- Reduce tumour lysis syndrome (WCC raised) → allopurinol, hyperhydration
- Cross match for blood tranfusion
- Transfer to specialist centre
- Platelet transfusion
- Bone marrow aspirate
- Chemotherapy (remission (pred) → maintenance (6-Mercaptopurine)
+ supportive care
- Blood products
- Antibiotics for any fever
- Prophylactic Abx to prevent PCP
- Anti-emetics
- Intrathecal methotrexate for CNS involvement
What is the prognosis for leukaemia
Children: 5-year disease-free survival of 80%
Adults: 5-year disease-free survival of 30-40%
Poor prognostic markers:
Age <2 or >10
Non-Caucasian
T/B-cell surface markers
Male sex
What are the causes of CLL
Accumulation of incompetent lymphocytes
Autoimmune disease:
- Haemolytic anaemia (10%)
- Thrombocytopenia
- Combination (Evan’s syndrome)