A case of epithelioid haemangioendothelioma sited at pulmonary valve, with an excrescence growing invading pulmonary artery troncus and its principal branches, in a 56-year-old woman is reported. The evolutive behavior simulated some clinical situations which made difficult the diagnosis: a mild-moderate pulmonary stenosis, a general syndrome, and, finally, an acute pulmonary thromboembolism that carried to an aggressive management which conducted to the entity diagnosis.