Spontaneous haemarthrosis after tenecteplase administration for acute ischaemic stroke

Tenecteplase (TNK), a genetically modified fibrinolytic agent, is increasingly used for acute ischaemic stroke because of its single-bolus administration and fibrin specificity. Haemarthrosis is an uncommon manifestation of bleeding that may occur in the setting of systemic fibrinolysis. We describe a man in his 70s who developed sudden right knee pain and swelling consistent with haemarthrosis 4 hours after TNK administration without preceding trauma or coagulopathy. Arthrocentesis confirmed the diagnosis and provided relief from symptoms. This case describes a rare bleeding complication following TNK therapy and adds to the limited literature on atypical extracranial bleeding after thrombolysis. It emphasises the need to consider such presentations during post-thrombolysis monitoring.