Endosonography of a Pulmonary Artery Obstruction in Echinococcosis

A 44-year-old woman with a history of pulmonary embolism and abdominal echinococcosis complained of sudden thoracic pain and shortness of breath. A D-dimer of 77.5 mg/l (reference ≤0.5 mg/l) was found. Chest CT scan revealed obstruction of the right lower and middle lobe pulmonary artery (PA). Anticoagulation therapy was initiated for the presumed diagnosis of recurrent pulmonary embolism. However, due to persistent symptoms of dyspnea, follow-up CT angiography of the chest was performed 3 months later. A persistent PA obstruction was found and the presumed diagnosis of embolism was questioned. Subsequently, endobronchial ultrasound (EBUS) imaging was performed to support an alternative diagnosis. EBUS imaging showed an inhomogeneous, sharply demarcated, intravascular lesion with round hypoechoic areas compatible with cysts. The diagnosis of embolism was rejected and treatment with albendazole was initiated for pulmonary echinococcosis. Echinococcosis is a parasitic disease and cystic spread in the PA is exceptional. The patient has remained stable for more than 4 years. In case of disease progression, including progressive PA obstruction or life-threatening hemoptysis, surgical resection will be considered.