Bone marrow failure
- Created by: MazzaW
- Created on: 06-12-19 13:59
Pancytopenia
Anaemia, neutropenia and thrombocytopenia
Neutropenia: very dangerous, especially if febrile. Classified according to neutrophil count (mild = 1.0-1.5, moderate = 0.5-1.0, severe = 0.1-0.5). Major risk if febrile neutropenia/neutropenic sepsis.
Thrombocytopenia: classified according to platelet count (mild = 50-100, moderate = 20-50, severe = <20). Causes predisposition to bleeding (bruising, petechiae, risk of intracranial/GI haemorrhage)
Ix: Hx, Ex, drug Hx, hepato/splenomegaly, blood film, reticulocytes count, B12/folate (megaloblastic anaemia- should always check this first as it is easily correctable), abdo USS/CT (organomegaly, occult bleeds), BM biopsy (hypocellular = aplastic anaemia, hypercellular = marrow infiltration- BM completely replaced by cancer)
Infiltration with cancer may be from a haematological cancer or it may be metastatic from breast/prostate/lung/renal/thyroid/melanoma
Aplastic anaemia
Rare, occasionally congenital.
60% cases are idiopathic (possibly autoimmune?)
Other 40% due to drugs: benzene, gold/penicillamine, chemo (usually reversible), sulphonamides
Rx: withdraw cause, supportive care (blood/platelet transfusions, Abx), immunosuppression (if autoimmune), stem cell transplantation if particularly severe
Myelofibrosis
Fibrotic condition where the BM is scarred over by collagen (replaced by scar tissue)
Body attempts to compensate by producing cells in liver and spleen -> hepatosplenomegaly
Only treatment is BM transplant
Acute leukaemia
Commonest reason for BM failure. Cancer cells are undifferentiated blasts.
Presentation: BM failure, often systemically unwell, rapid onset and progression, often flu-like illness, sweats, wt loss, anorexia. May have infiltration of other sites (CNS- leukaemic meningitis, testes- painless swelling, gums, skin, thymus- mediastinal mass on CXR, nodes)
Prognostic factors: age (younger=better), sex (females do better), cytogenetics, remission/speed of remission, relapse, blast count in blood, extramedullary disease
Causes: genetic predisposition, haematological disease, irradiation, chemicals (including chemo)
Dx: FBC (pancytopenia), deranged clotting, BM biopsy (diagnostic), tissue biopsy (if infiltration), chromosomal analysis
Acute leukaemia treatment
Rapidly fatal if untreated- need immediate intensive chemo (sperm banking 1st), treat infection, hydration, transfusion, allopurinol (high risk of tumour lysis syndrome), may need intrathecal chemo/transplant
Common S/E: N+V, BM failure (gets worse before it gets better), hair loss, tiredness.
Long-term: infertility, short stature, loss of intellect, lifelong increased Ca risk, psychological, cardiac risk
Chronic leukaemia
Cancer cells look like normal counterparts (differentiated)
BM function fairly normal at presentation. Indolent presentation.
Patients rarely unwell- may not need treatment.
Chronic illness: patients can live with the disease for many years
Myeloid leukaemias: cancer cells derived from neutrophils/RBCs/platelet precursors. Prevalence increases with age.
Lymphoid leukaemias: cancer cells derived from immune cells/lymphocytes. Most common cancer of childhood.
CML: due to Philadelphia chromosome (9:22 BCR:ABL translocation), treat with tyrosine kinase inhibitors
Myelodysplastic syndrome
Progressive BM failure- disease of the elderly.
Difficult to treat.
Pre-leukaemic. Can be terminal either from BM failure or from transformation to acute leukaemia.
Can be induced by chemo/radiotherapy.
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