Saturday, 9 October 2010

MRCP revision battle 28.6: Chronic Myeloid leukaemia

Chronic myeloid leukaemia is an uncontrolled clonal proliferation of myeloid cells.

It tends to affect middle aged people (40 to 60 years)

Classical presentation is with:
  • decreased weight
  • tiredness
  • sweating

Possible additional presentations are:
  • gout due to increased purine breakdown
  • abdo pain due to splenomegaly
  • bleeding due to platelet dysfunction

Approximately 30% are detected by chance.

Features include:
  • elevated WCC - often 100-500
  • massive neutrophilia with left shift
  • low neutrophil alkaline phosphatase
  • splenomegaly in >75%

The philadelphia chromosome is present in >80% of cases

The philadelphia chromosome:
  • is a hybrid chromosome formed by t(9;22)
  • forms a gene BCR-ABL which results in excess tyrosine kinase activity
  • found in 80% CML, 5% children with ALL, 25% of adult ALL and 1% adult AML.
  • is associated with a good prognosis in CML but a poor prognosis in all other leukaemias

Treatment for CML is:
  • hydroxyurea
  • imatimib = glivec = specific BCR-ABL tyrosine kinase inhibitor
  • bone marrow transplant

CML transforms to AML in 80% of cases and ALL in 20%

Last battle of the day is Gertmann's Syndrome...