26. Leukemias Flashcards
What is leukemia
malignancy of white cells in bone marrow with an excess of blasts
white cells: myeloid or lymphocytes
-acute or chronic
Symptoms and signs of leukemia
- reduced RBC, WBC and platelets
- hyperleukocytosis -> leukostasis -> blood supply of organs blocked -> organ failure
- may or may not have bone pain and lymphadenopathy
What is the end product of differentiation of myeloid and lymphoid stem cells
myeloid
- basophil
- eosinophil
- neutrophil
- monocyte
- platelets
- erythrocyte
lymphoid
-lymphocyte
Benign WBC disorder
- reactive increase in number - ‘philias’/-‘osis’
- neutrophilia - bacterial sepsis
- lymphocytosis - viral, immune
- eosinophilia - allergy, parasites - decrease in number - ‘penias’
- neutropenia, lymphopenia, eosinopenia, pancytopenia
- casued by drugs, viral infections, radiation, chemotherapy
WBC neoplastic disorder
- leukemia (malignant)
- increased number of blast cells in bone marrow and blood
- acute/chronic and myeloid/lymphoid - lymphoma (malignant)
- nodal/extranodal
- Hodgkins/non-Hodgkins (myeloma) - myeloproliferative syndrome (benign)
- myelodysplastic syndrome (benign)
Example of acute leukemia
- acute myeloblastic leukemia
- acute lymphoblastic leukemia
Example of chronic leukemia
- chronic myeloid leukemia
- chronic lymphocytic leukemia
General clinical features of leukaemia
- bone marrow replacement by blast cells with marrow failure
- anaemia (low RBC)
- fever - infection (low WBC)
- bleeding tendency (low platelets) - hyperviscosity - excess cells
- tender bones
- lymphadenopathy, splenomegaly
- leukaemic infiltration
Where does acute myeloblastic leukemia arises from
malignant transformation of a myeloid precursor
- most frequent leukemia in neonate
- incidence increases with age
Clinical features of acute myeloid leukemia
-gum hypertrophy
-hepatosplenomegaly (less common)
-skin deposit
-lymphadenopathy
-renal damage
-disseminated intravascular coagulation
AML + DIC -> intracranial haemorrhage
Clinical presentation of gum hypertrophy due to acute myeloid leukemia
- infiltration of gums by leukaemic cells
- bruises in top of mouth, tongue means that same goes in gut and brain
Where does acute lymphoblastic leukemia arises from
- most common malignant disease in children
- incidence decrease with age, with a second rise after 40 years
Signs of acute lymphoblastic leukaemia
- lymphadenopathy (mediastinal, cervical)
- hepatosplenomegaly
- bone pain (present very late)
- mediastinal mass
- testicular swelling
Lab investigation of acute leukemia
- FBC
- bone marrow aspirate and trephine
- immunophenotyping (flow cytometry)
- to determine type of cell - molecular analysis
a) Normal WBC count
b) acute leukaemia WBC count
a) 4.3 - 10.8 x 10^9/L
b) <1.0 x 10^9/L to 200 x 10^9/L
a) Normal platelet count
b) acute leukaemia platelet count (thrombocytopenia)
a) 150 - 400 x 10^9/L
b) <10 x 10^9/L
How does acute leukemia cause anaemia and thrombocytopenia
Leukemia is a type of cancer found in your blood and bone marrow and is caused by the rapid production of abnormal white blood cells. These abnormal white blood cells are not able to fight infection and impair the ability of the bone marrow to produce red blood cells and platelets.
What are blast cells
Blasts are precursors to the mature, circulating blood cells such as neutrophils, monocytes, lymphocytes and erythrocytes. Blasts are usually found in low numbers in the bone marrow.
What can you find from bone marrow aspiration and treiphine biopsy in acute leukemia
- able to confirm it is acute leukemia
- blasts increased
- usually hypercellular
What can you find out from immunotyping (e.g. flow cytometry) of acute leukemia
-determine whether the leukemia is lymphoid or myeloid
AML - t(8; 21) - translocation between chromosome 8 and 21
B-ALL - t(8; 14)
How do you manage acute leukaemia
chemotherapy with or without bone marrow transplant
Supportive medicine:
-treat infection - usually gram negative
-treat bleeding - platelet concentrate for bleeding episodes or low platelet count with fever
-fresh frozen plasma if coagulation screen results abnormal
-packed red cell for severe anaemia
What is chronic myeloid leukemia
malignancy of myeloid marrow cell
-mainly occuring in middle age (40-60y)
Immunotyping of chronic myeloid leukemia
Philadelphia chromosome, t(9; 22) - also presented in acute lymphoblastic leukemia
Lab investigation of chronic myeloid leukemia
marked leukocytosis - >50000 (abnormal)
marked splenomegaly, hepatomegaly
Diagnosis of chronic myeloid leukemia/chronic granulocytic leukemia
- FBC
- bone marrow aspirate and trephine
- immunophenotyping
- molecular: t(9; 22) and BCR-abl fusion gene
Principal of treatment for chronic myeloid leukemia
- relieve symptoms of hyperviscosity, leukocytosis, splenomegaly, and thrombocytosis
- hydration
- chemotherapy
- imatinib - tyrosine kinase inhibitor
- +/- bone marrow transplant
What is chronic lymphocytic leukemia
malignancy of marrow lymphocytes
-occur in older age
Clinical features of chronic lymphocytic leukemia
- marrow failure
- anaemia
- fever and bleeding - lymphocytosis and lymphadenopathy
- spleen and liver enlargement
Diagnosis of chronic lymphocytic leukemia
- FBC
- bone marrow aspirate and trephine
- immunophenotyping
- molecular
