Short answer
Acanthocytes, sometimes called spur cells, are red blood cells with irregular, uneven projections. They are different from burr cells, which usually have more regular, evenly spaced projections and are more often an artifact. Acanthocytes may be seen with severe liver disease, after splenectomy, with lipid or membrane disorders, hypothyroidism, malnutrition, or neuroacanthocytosis syndromes. Interpretation depends on how many cells are present, how fresh the smear is, and whether there are signs of hemolysis or liver dysfunction.
How to frame the finding
| Pattern | Common next question | Why it matters |
|---|---|---|
| Acanthocytes with liver abnormalities | Could advanced liver disease or spur-cell anemia be relevant? | Strong liver context makes the finding more significant. |
| Acanthocytes after splenectomy | Is reduced spleen filtering expected? | Spleen history changes interpretation. |
| Spiky cells on an older smear | Could this be artifact or echinocytes instead? | Fresh smear review can change the conclusion. |
| Acanthocytes with anemia or jaundice | Are hemolysis labs or a liver workup needed? | These patterns can indicate active red-cell destruction. |
Common reasons
The classic associations are severe liver dysfunction, abetalipoproteinemia, post-splenectomy states, hypothyroidism, neuroacanthocytosis syndromes, and malnutrition. Merck also notes liver dysfunction and post-splenectomy as key settings. In some cases, medicines or marrow disorders can also be part of the picture, but the smear pattern itself is not a diagnosis.
Freshness matters. If the smear was delayed or poorly prepared, spiculated red cells can appear because of artifact, and those may look more like echinocytes than true acanthocytes. That is why morphology review by a trained reader matters when the result is unexpected.
When follow-up matters more
Follow-up matters more when acanthocytes are numerous, the smear is unexpected, or there is anemia, jaundice, abnormal liver tests, hemolysis, lipid problems, or neurologic symptoms. A repeat smear review can help separate true acanthocytes from artifact.
Questions to ask
- Did the report specify acanthocytes, spur cells, echinocytes, or another spiculated red-cell type?
- Are bilirubin, AST, ALT, ALP, GGT, albumin, PT/INR, reticulocytes, or hemolysis markers abnormal?
- Is there known liver disease, spleen removal, lipid disorder, malnutrition, or thyroid disease?
- Was the smear fresh, and would repeat review help distinguish true acanthocytes from artifact?
- Are there symptoms such as jaundice, dark urine, fatigue, bruising, or neurologic changes?
What follow-up may include
Follow-up may include a repeat CBC and smear, liver tests, bilirubin, reticulocytes, LDH, haptoglobin, lipid testing, thyroid testing, and hematology review if the finding is persistent or paired with anemia, jaundice, or other smear changes.
When a blood-smear reference matters more
MedlinePlus blood-smear guidance matters when a red-cell shape finding needs to be interpreted as a pattern rather than a diagnosis. It helps anchor the result in smear quality, repeat review, and the CBC or hemolysis context that decides how seriously to take one abnormal shape.
FAQ
What are acanthocytes?
Acanthocytes are red blood cells with irregular, uneven spicules on the membrane. They are also called spur cells in some liver-disease contexts.
How are acanthocytes different from burr cells?
Acanthocytes usually have fewer, irregular projections, while burr cells or echinocytes tend to have more uniform, evenly spaced projections. The distinction matters because artifact is more common with echinocytes.
Can liver disease cause acanthocytes?
Yes. Severe liver dysfunction is a classic cause, and acanthocytes may be part of spur-cell anemia in advanced liver disease.
What other conditions can be associated with acanthocytes?
Acanthocytes can be seen after splenectomy, in abetalipoproteinemia or other lipid disorders, hypothyroidism, neuroacanthocytosis syndromes, and malnutrition.
Could acanthocytes just be an artifact?
Yes. A delayed or poorly prepared smear can create spiculated red cells that mimic acanthocytes, so a fresh smear and expert review matter when the distinction is unclear.
What follow-up may be needed?
Follow-up may include repeat smear review, liver tests, bilirubin, hemolysis labs, lipid testing, thyroid testing, and hematology review when the morphology is persistent, numerous, or paired with anemia or jaundice.