Patient: A 45 year old female
Presentation: Patient was referred by the GP with fatigue, weight loss and recent chest infection, requiring prolonged antibiotics. Full blood count was done by GP revealed:-
Haemoglobin 9.0, White Blood Cells 3.1, Neuttophils 1.2, Platelets 76 and Mean Cell Volume 112.
The patient subsequently undergoes a marrow biopsy.
Morphology reveals three features:-
Erythroid series (red arrows)
Megakaryocytes which are hypolobated, small and micromegakaryocytes (green arrows)
Myeloid series, reduced hypogranular maturation and occasional blasts (blue arrows), monocytes also noted.
The immunophenotyping results confirm an excess of CD34+ cells (17%) and CD117+ (26%). The flow plots confirm that CD34 and CD117 expression is on myeloid cells, with coexpression of CD13 and CD33, indicating that these are myeloblasts.
There is evidence of myelomonocytic maturation, 49% of cells express CD11b+, 14% of cells express CD14 (mature monocytes), 18% of cells express CD16 (granulocytic).
The final diagnosis is Acute myeloid leukaemia (AML) with myelodysplasia-related changes.
In the WHO classification there are three possible reasons for assigning cases to this subtype:
AML arising from previous MDS or MDS/MPN
AML with an MDS-related cytogenetic abnormality
AML with multilineage dysplasia
To assign AML to this subtype, dysplasia must be present in at least 50% of the cells in at least two BM cell lines.
For this subtype, the patient should not have been exposed to prior cytotoxic therapy (this would be classified as therapy-related).
What additional information may be prognostically relevant?