Chronic myelogenous leukemia
A form of leukemia, chronic myelogenous leukemia (or CML)
is a clonal stem cell disorder characterized by excessive proliferation of myeloid cells.
Signs and symptoms
The disease is often without specific symptoms. Often it is detected on a routine full blood count.
Symptoms can include: malaise, low grade fever, increased susceptibility to infections, anemia and thrombocytopenia (although an increased platelet count — thrombocytosis — is often a feature).
Diagnosis
CML is often suspected on the basis on the full blood count. When the index of suspicion is high, a bone marrow biopsy is required to distinguish CML from other diseases that feature the same symptoms.
Ultimately, CML is diagnosed by detecting the Philadelphia chromosome (a translocation between the 9th and 22nd chromosome leading to an abberant protein that drives cell division). This translocation leads to bcr-abl fusion and activation of protein tyrosine kinase cascade.
Epidemiology
CML occurs in all age groups, but most commonly in the middle-aged and elderly.
Treatment
Chronic-phase CML is treated with:
Complications
In a proportion of patients, the disease remains indolent. In a number, however, it proceeds to accelerated phase and eventually blast crisis, which is virtually indistinguishable from acute myelogenous leukemia and has a very high mortality rate. This stage can most effectively be treated by a bone marrow transplant after high-dose chemotherapy.
