Acanthocytes and schistocytes on the smear: haemangiosarcoma
11-year-old German Shepherd with acute weakness, pale mucous membranes and a distended abdomen. Ultrasound shows a cavitated splenic mass and free fluid.
| Parameter | Result | Reference |
|---|---|---|
| Haematocrit | 22% | 37–55 |
| Reticulocytes | 160,000/µL | < 60,000 |
| Platelets | 55,000/µL | 200,000–500,000 |
| Blood smear | Acanthocytes, schistocytes, nucleated red cells | — |
Which statement about these findings is correct?
chevron_right Show answer and explanation
A. The schistocytes indicate the anaemia is immune-mediated
IMHA is associated with spherocytes and agglutination. Schistocytes are fragments caused by mechanical damage on abnormal endothelium or fibrin.
B. Acanthocytes and schistocytes in a dog with a splenic mass suggest haemangiosarcoma, often with DIC
Correct. Red cells fragment as they pass through abnormal tumour vessels and fibrin, and acanthocytes reflect altered membrane lipids. Thrombocytopenia may be due to consumption; assess coagulation.
C. Acanthocytes are an artefact of slow smear drying
Drying artefact produces echinocytes (crenation), with short, regular spicules. Acanthocytes have a few irregular projections and are a genuine finding.
D. The smear confirms haemangiosarcoma and makes histopathology unnecessary
These findings raise suspicion, but they also occur with haematomas and other lesions. Definitive diagnosis requires histopathology.
lightbulb Key takeaway
Distinguish echinocytes (artefact, regular spicules) from acanthocytes (few irregular spicules). With suspected splenic haemangiosarcoma, run coagulation tests, thoracic radiographs and echocardiography (right atrium) before splenectomy.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.