Helmet cells

By William Aird

Hemet cell (blue arrow) in a patient with valve hemolysis. Amputation of these cells results in a straight border which sharp angulated edges (vs. the “flaps” in the horn cell). The missing cell portion corresponds to the fragments that have been split off as a result of a break on a fibrin strand (100x, oil).

Red blood cell, shape abnormality, schistocyteHelmet cell
DefinitionFragmented cell that has been amputated, leaving a straight border with sharp angulated edges (the missing parts of the cell have been split off into pieces, including triangular cells)
Conditions associated with the shape abnormalityThrombotic microangiopathy (TMA), macroangiopathic hemolytic anemia
Mechanism of formationFragmentation of red cell, for example as a result of a break on a fibrin strand
Source/authorWilliam Aird
Reviewed and edited byParul Bhargava
ReferencesInt J Lab Hem 2012;34:107-116