Pulmonary embolism masquerading as pulmonary arteriovenous malformation on computerized tomography

A 57-year-old man with massive hemoptysis was thought to have a pulmonary arteriovenous malformation (PAVM) on the basis of computerized tomography of the chest. Angiography, however, revealed a pulmonary artery embolus as the case of the hemoptysis; the tomographic appearance of PAVM had been mimicked by the delay of contrast material within the involved pulmonary artery proximal to the occluding embolus. This finding suggests caution in the use of CT to diagnose PAVM, especially in clinical situations compatible with other diagnoses, and confirms the importance of pulmonary angiography in the definitive evaluation of suspected PAVM.