Asymptomatic partial regression of cerebral arteriovenous malformation without treatment: Case report and literature review

Background: Spontaneous regression of arteriovenous malformations (AVMs) is usually associated with bleeding, but sometimes asymptomatic regression occurs. Case description: We describe a case of spontaneous regression of AVM without evidence of hemorrhagic event. A 60-year-old otherwise healthy woman came to our hospital with complaints of headache. Digital subtraction angiography (DSA) showed an AVM with a 1.4 × 1.0 × 0.9 cm nidus in the right temporal lobe. The patient decided on observation without treatment rather than stereotactic radiation therapy or direct surgery. Seven years later, DSA revealed partial regression of the AVM. Venous ectasia and the nidus had decreased in size, and the nidus was obscure, especially around the feeding artery. No obvious features of hemorrhage were detected. Conclusions: Spontaneous regression of AVM is the result of multiple interacting factors. Structural changes to the AVM and histopathological changes may be important.