20.08 A 70-Year-Old Man with Fever, Fatigue and Dyspnoea of Recent Onset
colleague had already done the diff, but she pays for it and I am in no way
complaining. I felt the diff was 98% lymphocytes and 2% neutrophils
I felt the diagnosis was CLL (Chronic lymphocytic leukemia) with a haemolytic anaemia
The obvious next step was to perform direct antiglobulin test (DAT), a reticulocyte count and lymphocyte subtyping
To answer the questions:
1 Comment on the results of the erythrocyte indices.
The MCV is
very raised and haemoglobin very low.
The red cell indices show an implausibly low MCHC suggesting something awry in the red cell indices measurements/calculations.
2 In view of all the laboratory findings, how do you explain the abnormalities of the erythrocyte indices?
histogram shows that a population of huge (relatively) cells is present.
Red cells and white cells are counted together by the impedance technique which does not cause issues at usual levels of white cell count. However when the white cells count is high it can cause an erroneous overestimation of the red cell count and mean cell volume and consequently haematocrit.
Thus the MCHC is calculated wrongly (i.e. very low)
3 Which results of the blood count do you think are really informative? Would you validate them?
These red cell results are not accurate (i.e. wrong). The sample should be diluted and re-analysed.
4 What is the most likely mechanism of this patient’s anaemia? (The answer to this question must not be repeated in the diagnostic hypotheses.)
The presence of polychromasia and spherocytes suggest a possible haemolytic anaemia.
I did ok… not sure I understood the last question though...