Glanzmann thrombasthenia detected because of knee hemarthrosis: a case report.

Glanzmann thrombasthenia (GT) is a rare bleeding syndrome, which is characterized by a lack of platelet aggregation. We report a case of GT that was first detected because of the presence of hemarthrosis of the knee. The patient was an 8-year-old boy who presented with a sudden, painful left knee after outdoor games. Till the first visit to our hospital, he had not been diagnosed with GT despite a history of bleeding tendency, notably purpura in areas of easy bruising and prolonged bleeding time after abrasions and insect stings. Gross blood was found at arthrocentesis of the left knee, and GT was diagnosed on the basis of prolonged bleeding time, lack of platelet aggregation with ADP and collagen, and absence of platelet surface glycoprotein IIb/IIIa. Although hemarthrosis of GT is rare, this disease should be considered in a patient with bleeding tendency and prolonged bleeding time.