Regression of a pulmonary arteriovenous malformation after acute interstitial nephritis

A 68-year-old woman was scheduled to undergo percutaneous embolization of a pulmonary arteriovenous malformation (PAVM) to prevent a paradoxical embolic event. After contrast-enhanced computed tomography (CT) was performed to carefully evaluate the PAVM, she developed acute interstitial nephritis, which required steroid therapy. Moreover, her D-dimer level increased, which was suggestive of thrombus formation. After nine months, we noted that the affected vessels had markedly decreased in size, and the fistula had almost disappeared on unenhanced CT images. To our knowledge, this is the first case report to describe the regression of a PAVM, detected by CT, after the onset of acute interstitial nephritis.