Sep

4

2021

Keratocytes (Horn Cells)

By William Aird

Horn cell (arrow) in a 28 year-old man with thrombotic thrombocytopenic purpura (TTP). Note the pair of spicules separated by a semicircular concave segment of membrane, giving the appearance of horns (100x, oil).
This smear from the same patient above shows a horn cell (arrow) and three polychromatophilic cells (P) (100x, oil).

ParameterProperties
Red blood cell, shape abnormality, schistocyte Keratocyte
Also known asHorn cell
DefinitionFragmented red cell (a type of schistocyte) that has a pair of spicules separated by a semicircular concave segment of membrane.
DdxHelmet cells
Conditions associated with the shape abnormalityThrombotic microangiopathy (TMA), macroangiopathic hemolytic anemia
Mechanism of formationFormed by rupture of pseudovacuoles, which arise from the fusion of two frayed membrane ends of damaged red cells.
Source/authorWilliam Aird
Reviewed and edited byParul Bhargava