Intracardiac and pulmonary arterial thrombosis as a first presentation of Behçet's disease.

Behçet's disease (BD) is a rare vasculitis characterised by mucocutaneous lesions and ocular, vascular and neurological manifestations. We report a man in his early 20s who presented with dyspnoea, haemoptysis, pulmonary arterial thromboses and a large right ventricular thrombus. Initial investigations for infectious and autoimmune causes were negative, complicating diagnosis. A revisited history and new examination revealed oral and genital aphthosis, fulfilling the international criteria for BD. The patient was treated with anticoagulation and high-dose immunosuppression, resulting in rapid clinical improvement and resolution of the intracardiac thrombus. This case highlights the diagnostic challenge of BD when vascular manifestations precede recognition of the more characteristic features of BD and emphasises the therapeutic challenges of long-term secondary prevention.