[Pulmonary arteriovenous aneurysm].

A case of large arteriovenous aneurysm in the right upper lobe of a 27-year old man is reported. The pulmonary angioma was responsible for a 30% shunt with hypoxia and polycythaemia but was only discovered while looking for the origin of a cerebral abscess. A few weeks after surgical treatment of the cerebral abscess, the right upper lobe was excised with immediate correction of the hypoxia. This case shows that pulmonary angiomas can sometimes be revealed by neurological complications, and that visceral angiomas should not remain undiagnosed. They should be considered as part of a Rendu-Osler disease, the familial character of which may contribute to an early diagnosis.