macrothrombocyte

A platelet that is larger than usual—e.g., the size of an RBC—a finding typical of Bernard-Soulier syndrome (BSS); up to 10% of normal platelets are ‘giant’—i.e., ‘squashed’ and oversized
DiffDx When > 20% of platelets are giant: idiopathic thromocytopaenic purpura (ITP), lymphoproliferative disorders, myeloproliferative disorders, reticulocytosis, disseminated intravascular coagulation (DIC), systemic lupus (SLE), grey platelet syndrome, May-Hegglin anomaly, type 2B von Willebrand’s disease, thrombotic thrombocytopaenic purpura (TTP)

macrothrombocyte

(măk″rō-thrŏm′bō-sīt) [″ + thrombos, clot, + kytos, cell] A large platelet seen in some leukemias and rare disorders of platelets.