An 81-year-old woman with pyelonephritis caused by Escherichia coli developed asymptomatic thrombocytopaenia (platelet count 71 000 µl−1) on the third day of hospitalization. A peripheral blood smear revealed monocytes () and neutrophils () with platelets in their cytoplasm. In particular, thrombophagocytosis was observed in more than 50% of neutrophils. Laboratory workup for other causes of thrombocytopenia including disseminated intravascular coagulation was negative. The patient completed an uneventful course of antibiotic therapy. Thrombophagocytosis is a rare phenomenon. Only two cases of peripheral thrombophagocytosis have been reported previously: one in urosepsis caused by Citrobacter freundii Citation[1] and the other one in B-cell lymphoma Citation[2]. We are also aware of three reported cases of thrombophagocytosis in the bone marrow: two in haemophagocytic syndrome Citation[3], Citation[4] and one in juvenile dermatomyositis Citation[5]. The binding of pathogens to platelets in septicaemia is thought to mediate thrombophagocytosis by neutrophils and monocytes.
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