[Invasion of the pulmonary artery by an undifferentiated carcinoma]

The diagnosis of chronic obstruction of the pulmonary artery is difficult. We present the case of a woman with an invasive, undifferentiated carcinoma of the pulmonary artery.

A 61 year old woman complained of increasing dyspnoea. This was evaluated by computed tomography which showed a defect in the main pulmonary artery. There was no clinical or radiological improvement following anticoagulant treatment for two months. A repeat CT scan showed a persisting intravascular defect and the diagnoses considered included post-embolic pulmonary arterial hypertension and angiosarcoma. A surgical biopsy was performed and pericardial and aortic tumour nodules were found during the operation. The pathological examination revealed undifferentiated carcinoma. Further investigations failed to reveal the primary site.

Invasion of the pulmonary artery by angiosarcoma or other tumour is part of the differential diagnosis of chronic thromboembolic disease. The diagnosis rests on histology obtained by an intravascular or surgical procedure. Complete surgical excision may be possible in angiosarcoma but it was impossible in our patient. The patient died despite two courses of chemotherapy and targeted therapy with erlotinib.