Smudge cells
Smudge cells
Smudge cells seen most commonly in
[A] ALL
[B] CLL
[C] AML
[D] CML
Zeta-chain-associated protein kinase 70 (ZAP-70) expression is a prognostic marker for
[A] ALL
[B] CLL
[C] AML
[D] CML
Smudge cells
Characteristic disintegrated or crushed white cells in the blood film of CLL patients called smudge cells or basket cells.
Gumprecht’s nuclear shadows
What is a Gumprecht shadow?
Smudge cells seen on peripheral blood smear.
Smudge cells have also been called Gumprecht shadows, named after German scientists and researcher Ferdinand Adolph Gumprecht, who observed these on slides of patients with chronic lymphocytic leukemia (CLL).
They were first described in 1896 by Gumprecht as white blood cells with broken-down nuclei (Gumprecht’s nuclear shadows)
Possible Mechanism of Smudge cells formation in peripheral slide blood film
These cells smudge when blood films are made, probably because they are more fragile than normal cells and prone to traumatic disruption during blood film preparation
Zeta-chain-Associated Protein kinase 70 (ZAP-70) expression
One of the standard prognostic markers is the zeta-chain-associated protein kinase 70 (ZAP-70) expression
Percentage of smudge cells [ at presentation of CLL ]
In newly diagnosed CLL patients Percentage of smudge cells [ at presentation of CLL ] could be used as a surrogate marker for ZAP-70 expression and an additional prognostic marker for disease progression
ZAP70 expression assessed by immunohistochemistry is a reliable surrogate marker of the somatic mutation status of the immunoglobulin heavy chain genes in chronic lymphocytic leukemia, and predicts time to progression.
Smudge cells (also called basket cells) are damaged or ruptured white blood cells that appear on peripheral blood smears as smudgy, amorphous nuclear material without intact cytoplasm.
Key Points about Smudge Cells
| Feature | Details |
|---|---|
| Appearance | Faint, smeared nuclear material; no visible cell membrane or cytoplasm |
| Cause | Fragility of leukocytes, often due to abnormal lymphocytes |
| Common Association | Chronic lymphocytic leukemia (CLL) |
| Mechanism | Fragile lymphocytes rupture during slide preparation |
| Diagnostic Relevance | Supportive but not pathognomonic; can appear in other lymphoproliferative disorders |
| Prevention in Lab | Adding albumin to the smear preparation can reduce smudge cell formation |
📌 Clinical Note:
In CLL, smudge cells are often abundant and accompany small, mature lymphocytes in the smear.
