Diagnosis: Artifact on blood smear
• Burr cells (echinocytes) are red blood cells with projections equally spaced over the entire cell surface.
• They are most commonly seen on blood smears that were prepared more than 8 hours after phlebotomy.
• They can also be seen in patients with uremia or burns and after a red cell transfusion.
• Burr cells need to be distinguished from acanthocytes, which show irregularly spaced projections.
• Burr cells are reversible; patients who have had transfusions will only have Burr cells within approximately 48 hours after transfusion.
