[Anticoagulant-induced pseudo-thrombocytopenia: an important laboratory artifact]

In the medical unit of our regional hospital we observed eight cases of anticoagulant-related pseudothrombocytopenia within two years. Attention is drawn to this often misdiagnosed laboratory artefact. In every unexpected thrombocytopenia found by automatic cell-counting a simple blood smear should be studied especially for thrombocyte-aggregates and the automatic platelet-count should be repeated using another anticoagulant, before other investigations are undertaken.