Abstract
We report on a 36-year-old woman suffering from metastasized breast cancer and severe dyspnoea owing to right heart failure. Symptoms and findings were highly suggestive of pulmonary embolism. In rare cases, pulmonary embolism is caused not by migration of venous thrombi but by emboli of other origin. Patients with cancer can suffer from non-thrombotic pulmonary embolism, either by (macroscopic) embolization of tumour mass or by microembolism also known as microscopic tumour microangiopathy. In patients with cancer with clinical presentation highly suggestive of pulmonary embolism, with echocardiographic findings confirming right ventricular dysfunction, and with negative CT angiography, pulmonary tumour microembolism should be considered as possible diagnosis.