laboratory findings

Last reviewed 01/2018

• red cells:
• usually anaemia
• cell morphology is abnormal with macrocytes, microcytes or bizarre shapes
• MCV is normal or increased

• WBC:
• usually normal or reduced; but raised in chronic myelomonocytic leukaemia where monocyte count may exceed 10 x 10^9 / l
• neutropenia is common; neutrophils may be hypogranular with one or two segments (Pelger-Huet cells), or may be hypersegmented

• platelets - normal or reduced; some may be hypogranular

• bone marrow - hypercellular despite low counts:
• erythroid hyperplasia is common - abnormalities include megaloblastoid changes, nuclear budding or multinucleate erythroid precursors
• granulocyte precursors often lack cytoplasmic granules
• dwarf megakaryocytes with unilobed nucleus are characteristic

• 60% of patients have chromosomal abnormalities most commonly 5, 7, 20, or Y, and trisomy 8.