A 65‐year‐old man presented with 91% body surface area full‐thickness burns that he sustained in a shack fire. It was suspected that the patient, who was an epileptic, had a seizure, fell, and knocked a paraffin stove over, setting the shack alight.
He arrived at the hospital 2 h later in a critical condition. A full blood count (FBC) performed on an Advia® 2120i (Siemens Healthineers, Erlangen, Germany) automated haematology analyser revealed marked thrombocytosis (1157 × 109/L), leucocytosis (18.58 × 109/L) and a normal haemoglobin level (143 g/L). The red blood cell (RBC) indices showed macrocytosis (mean corpuscular volume 101.6 fL) and hypochromia (mean corpuscular haemoglobin 26.2 pg), while the RBC distribution width was elevated (24.4%).
Review of his peripheral blood film showed no apparent increase in platelets. However, the erythrocytes displayed marked anisopoikilocytosis with numerous spherocytes, microspherocytes, microdiscocytes and irregular fragments of cytoplasm, with budding from erythrocytes being apparent. Echinocytes were prominent, likely due to his acute kidney injury (figure, all panels, Wright's stain, objective ×50 lens). Neutrophils were increased with toxic granulation and vacuolation (bottom left panel, objective ×50 lens).
The patient succumbed to his injuries 4 h after the accident and no repeat FBC or film could be obtained.
These photomicrographs illustrate the distinctive RBC morphology that may be seen with severe burns, usually within the first 4 h following the injury. Thermal injury disrupts the RBC membrane resulting in budding (bottom middle panel), which is typically detected as microspherocytes (all panels) and microdiscocytes (small round schistocytes that retain their central pallor) (top panels). 1 These microspherocytes and microdiscocytes may be incorrectly counted as platelets by automated FBC haematology analysers, resulting in pseudothrombocytosis. 2 , 3 A similar artefact may occur in thrombotic microangiopathies if schistocytes and microspherocytes are erroneously counted as platelets, masking the thrombocytopenia that characterizes these disorders. Likewise, in a patient with severe burns, the thrombocytopenia that occurs with disseminated intravascular coagulation may be masked.
These limitations are classically associated with automated haematology analysers that rely on impedance to count platelets. Analysers that count platelets after fluorescent RNA labelling (Sysmex) or immunolabelling (Abbott) usually avoid this trap. 3 Optical analysers such as the Advia® 2120i, which measure platelet volume and composition simultaneously, are theoretically able to differentiate platelets from RBC fragments due to diffraction analysis. 3 However, as this case clearly demonstrated, the Advia® 2120i may not be exempt from generating spuriously elevated platelet counts in patients with severe burns.
Pseudothrombocytosis should be considered in any patient with severe thermal injuries when an FBC is performed on an automated haematology analyser, particularly those that rely on impedance or optical light scatter to count platelets. This case underscores the importance of a blood film review for any abnormal platelet count.
FUNDING INFORMATION
This research received no specific grant from any funding agency in the public, commercial or not‐for‐profit sectors.
ETHICS STATEMENT
Ethical clearance for this case study was obtained from the Health Science Research Ethics Committee of the University of the Free State (UFS‐HSD2025/0296/2705). Permission was obtained from the Northern Cape Department of Health.
PATIENT CONSENT STATEMENT
Informed consent for publication of this peripheral blood film image could not be obtained from the patient who demised from his injuries 2 h after admission to the hospital. Attempts to locate the next of kin to obtain permission to publish this report were unsuccessful. No patient identifying information is provided. The Health Science Research Ethics Committee of the University of the Free State granted a waiver of consent.
ACKNOWLEDGEMENTS
The author would like to acknowledge Dr. Mellisa Bergman, who identified this case in the laboratory.
REFERENCES
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