Synopsis
Use blood-film morphology to verify automated counts, recognise time-critical haematological patterns and direct confirmatory testing without turning a descriptive cell shape into a final diagnosis.
- Read the film alongside the full blood count, reticulocytes, clinical question and sampling history. Morphology without the numerical and clinical context is vulnerable to over-interpretation.
- Start at low power for distribution, rouleaux, agglutination, large abnormal cells and platelet clumps, then use higher power for red-cell shape, white-cell maturation, inclusions and platelet morphology.
- Schistocytes indicate mechanical fragmentation but are not synonymous with TTP; thrombocytopenia, haemolysis, renal, neurological and coagulation findings decide the thrombotic-microangiopathy or DIC pathway.
Key red flags
Schistocytes with falling haemoglobin, thrombocytopenia, high LDH and low haptoglobin indicate fragmentation. Neurological, renal or cardiac involvement increases urgency for a thrombotic-microangiopathy pathway.
Investigation priorities
Confirm morphology, estimate abnormal-cell burden and issue time-critical alerts.
Management branches
Schistocytes accompany anaemia, thrombocytopenia or new renal, neurological, cardiac or bleeding features.
- Preferred first-line assessment is urgent repeat FBC, reticulocytes, LDH, bilirubin, haptoglobin, renal profile, urinalysis, coagulation, blood pressure and direct antiglobulin testing, with expert film confirmation.
- If TTP is plausible, send pre-plasma ADAMTS13 and escalate immediately to the regional TTP service; do not wait for a historical pentad or the activity result before specialist treatment decisions.
Key medicines
Tretinoin (all-trans retinoic acid) for suspected APLStart 45 mg/m² per day by mouth in two divided doses immediately on morphological suspicion, under the acute-leukaemia protocol, without waiting for genetic confirmation.