EDTA-dependent pseudothrombocytopenia complicated by eosinophilic pneumonia

EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) is a phenomenon that occurs in vitro when EDTA reacts with harvested blood. EDTA-dependent pseudothrombocytopenia usually does not indicate thrombocytopenia in vivo. Here, we report the first case of EDTA-PTCP complicated by eosinophilic pneumonia. A 70-year-old man with rectal cancer was admitted to the hospital for a liver abscess and rectal cancer. At the time of admission, his platelet count was 20,000/μL, but a peripheral blood smear showed platelet aggregation and the platelet count for a kanamycin-added EDTA blood sample was 180,000/μL. The patient's respiratory status worsened after treatment for the liver abscess and rectal cancer. The patient's bronchoalveolar lavage contained 45% eosinophils, and a diagnosis of acute eosinophilic pneumonia was made. In recent studies, the occurrence of eosinophilic disease has been shown in idiopathic thrombocytopenic purpura. EDTA-dependent pseudothrombocytopenia is an in vitro phenomenon, although platelet activation that results in eosinophil invasion may occur in severe cases.