This week’s case comes from an 84-year-old male who was referred to the haematology team after routine blood tests showed a markedly raised white cell count. Clinically, he reported several weeks of general fatigue but no acute symptoms. He was otherwise well and presented via his GP.
Full blood count results:
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White cell count: 823 ×10⁹/L (Note: This value exceeded the analyser’s linearity range)
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Red cell count: 2.69 ×10¹²/L
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Haemoglobin: 84–106 g/L (range reflects correction due to WBC interference)
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Haematocrit: 0.306
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MCV: 92.4 fL
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MCH: 31.0 pg
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MCHC: 335 g/L
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RDW: 13.5%
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Platelets: 164 ×10⁹/L
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MPV: 9.2 fL
A few images from the blood film:
Based on the images, the clinical presentation and the FBC results, what do you think the diagnosis may be?
How do you approach any parameter that exceeds analyser linearity?