Bone marrow aspiration
A bone marrow aspiration is necessary to diagnose acute myeloid leukemia.
Examinations performed on the aspirate:
- Microscopy, MGG staining and possible cytochemical staining
- Immunophenotyping (flow cytometry)
- Cytogenetics with directed testing using FISH or molecular genetic techniques
- Vital freezing of leukemia cells and/or RNA/DNA extraction for later molecular genetic analyses should be done, if possible.
Biopsy of the iliac crest is not obligatory unless the aspirate is inadequate. The biopsy can in some cases provide additional valuable information.
ABO typing, hemoglobin, leukocytes with differential counting, thrombocytes, blood smear, LD, albumin, creatinine, Na, K, Ca, phosphate, urate, glucose, CRP, bilirubin, AFOS, ASAT, ALAT, LDH, CMV.
- HLA typing – taken if there is a need for HLA compatible blood components
- Lysozyme – in case of raised lysozyme it is probable the patient has acute myeloid leukemia
- FLT3 analysis (PCR) – a prognostic factor which indicates high risk of recurrence
A lumbar puncture is performed when there is a clinical suspicion of CNS leukemia. Patients with M4-M5 with high LPK (leukocyte particle concentration) have an increased risk for spreading to the central nervous system.
A cytological examination of the aspirate is performed and possibly with immunophenotyping, cell counting and measurement of spinal protein. In case of elevated cell count, cytospin with MGG staining is performed.
Interpretations of findings in spinal fluid can be difficult as there may be contamination with blast containing blood during the spinal puncture.
In cases where an allogeneic stem cell transplant is considered, HLA typing of siblings and parents is done when remission is achieved. In a clinical situation, this means all patients under 60 who reach complete remission.
It is important to emphasize that this does not necessarily mean that there will be indication for allogeneic stem cell transplantation in all cases. This will depend on a number of prognostic factors, comorbidity and the course of the disease during and after the induction therapy.