Smudge Cells

By William Aird

Smudge cells (S) from a 72-year-old woman with chronic lymphocytic leukemia. Inset shows higher magnification of boxed area containing one smudge cell and one intact lymphocyte with coarsely condensed chromatin (L) (50x).

Single smudge cell (arrow) on a peripheral smear from a 59-year-old man with chronic lymphocytic leukemia. Smudge cells typically contain chromatin, but no identifiable cytoplasmic components. P, platelet (100x, oil).
White blood cell, lymphocyteSmudge cell
Also known asBasket cell
DefinitionRemnants of fragile cells that are generated during preparation of peripheral smear. They lack any identifiable cytoplasmic membrane or nuclear structure. They contain dense nuclear material and/or chromatin strands.
Conditions associated with the cell typeSeen on routine blood smears of virtually all patients with chronic lymphocytic leukemia (CLL); may also occur in other lymphoproliferative disorders and viral infections such as infectious mononucleosis.
Mechanism of formationMalignant or virally infected lymphocytes lymphocytes are more fragile than normal lymphocytes. These fragile lymphocytes rupture in the process of ex vivo smear preparation, forming smudge cells that consist largely of nuclear material.
Source/authorWilliam Aird
Reviewed and edited byParul Bhargava
ReferencesJ Clin Oncol. 2009;27:1844
Leuk Res. 2010;34:1680