Blood/Blood Cells and Cellular Components ›› Red Blood Cells ›› Abnormal Burr cell RBC (Echinocyte)* Click Here for Full Size Additional Image 1 Additional Image 2 › Microscopic Features: May be smaller or the size as a normal RBC Regular broader-base short blunt projections of red cell membrane › Normal % blood-PB, marrow-BM, lymphoid tissue-LN: PB: Rare to None BM: Rare to None LN: Rare to None › May Resemble: Spur cell Schistocyte Spherocyte Normal Mature RBC › Differential Diagnoses: Increased in: Artifact (e.g. older blood specimen) Uremia (e.g. chronic renal disease) Liver disease Hyperlipidemia Etc. › Classic Immunophenotype: N/A › Cartoon Image: Click and drag for direct comparison › Misc: Most often they are due to an artifact of smear preparation. Also one must inquire about the age of the blood sample.