Haem Malignancies Flashcards
What do myeloid precusor cells give rise to?
- Granulocytes:
- basophils
- neutrophils
- eosinophils
- mast cells
- monocytes –> macrophages - RBCs
- Megakaryocytes –> platelets bud off
What do common lymphoid precusors give rise to?
Lymphocytes:
- B cells
- T cells
- NK cells
*dendritic cells can arise from either this pathway or as part of granulocytes (from myeloid precursor)
Bone marrow samples - types and preferred sites
- bone marrow aspirate: takes a little of the liquid found in the bone marrow space
- bone marrow biopsy (trephine): takes a small sample of harder bone marrow tissue.
Preferred sites:
- iliac crest (anterior or posterior)
- tibia
- sternum
Acute leukaemia - definition
Neoplastic disease of immature blood cells (blasts) in the bone marrow. Can arise from myeloid or lymphoid lineage
Acute leukaemia - general features
- Tiredness, infection, bruising/bleeding
- High white cell count
- Low haemoglobin (anaemia)
- Low platelet count (thrombocytopenia)
- Low neutrophil count (neutropenia)
- High WCC due to infections
Acute leukaemia and infections
- Low neutrophil count (neutropenia) –> increased risk of infection (febrile neutropenia)
- chemotherapy –> mucositis (risk of mouth infections)
- Indwelling central venous line –> line infection (staph aureus)
Acute myeloid leukaemia (AML) - features
- mainly >65 years
- RF: Radiation, previous chemotherapy, congenital syndromes, previous myelodysplastic syndrome
- Tiredness, infection, bleeding, ecchymoses or petechiae
- auer rods on blood smear
What are auer rods?
Auer rods are cytoplasmic inclusions which result from an abnormal fusion of the primary granules.
- seen in acute myeloid leukaemia
- found on blood smear
Acute lymphoblastic leukaemia (ALL) - features
- 30% of childhood cancer
- 20% of adult acute leukaemia
- RF: Radiation, Downs syndrome, M>F
- +ve philadelphia chr common in adults
Symptoms and signs
- Tired, anaemic, bruising, bleeding and low platelets, weight loss
- Abdominal pain, lymphadenopathy, splenomegaly
What is the relevance of the philadelphia chromosome?
Cytogenetic abnormality results from chromosomal translocation t(9;22)(q34;q11) on the Philadelphia chromosome, found on molecular studies in:
- Chronic myeloid leukaemia (95%) - pathognomonic
- most common cytogenic abnormality in adult ALL
AML - treatment
- 3 to 4 cycles of combination chemotherapy
- Haemopoietic stem-cell transplant (HSCT) for some
ALL - treatment
- Induction (includes prednisolone/dexamethasone and vincristine) and consolidation chemotherapy (high-dose)
- HSCT or 2 years of maintenance therapy
- CNS prophylaxis throughout as can progress to/relapse in brain and spinal cord so intrathecal chemo +/- radio
- If Philadelphia positive ALL- also give Imatinib(Glivec)
- consider fluids, Abx prophylaxis, RBC transfusion etc
Acute vs Chronic leukaemia
ACUTE: no mature cells (blasts) therefore low neutrophils, lymphocytes etc.
CHRONIC: mature cells affected therefore high neutrophils, lymphocytes
Chronic leukaemia - def and types
Neoplastic disease of mature white blood cells in the bone marrow
Types:
- Chronic myeloid leukaemia (CML): overlaps with myeloproliferative disorders
- Chronic lymphocytic leukaemia (CLL): overlaps with lymphomas
Chronic lymphocytic leukaemia (CLL) - features
- Majority of pts > 60 (most common type in adults)
- Slow accumulation of CLL cells in blood, bone marrow, lymph nodes, liver, spleen
- Hepatosplenomegaly and lymphadenopathy
- B symptoms: night sweats, persistent fever, weight loss, itching
- +/- bleeding/easy bruising and anaemic
- Can transform to high grade lymphoma (5%)