Lethal progression of a fetal intracranial arteriovenous malformation.

Fetal intracranial vascular tumors present unique clinical challenges. Accurate diagnosis of the lesion, as well as an understanding of the local and systemic impacts, will guide the antenatal surveillance and the treatment plan and will determine the prognosis. Management will be altered by and dependent on intrauterine progression, gestational age, and fetal condition at birth. In addition, large vascular tumors can lead to the development of the Kasabach-Merritt sequence in the fetus and to either fetal or maternal hemodynamic impairment. Vascular tumors are either malformations or neoplasms. Color and pulsed wave Doppler sonography are useful for the identification of vascular lesions and help narrow the differential diagnosis. Once a vascular malformation is identified, a comprehensive anatomic survey is mandatory to determine whether there are coexistent malformations that impact either the diagnosis or prognosis. These lesions can have local mass effects, systemic hemodynamic effects, or both. Therefore, longitudinal assessment of the fetus is focused on the detection of lesion progression and on any fetal or maternal status changes. We report the prenatal diagnosis of an intracranial arteriovenous malformation (AVM) with a dramatic progression affecting both mother and fetus.