We report a case of prenatal diagnosis of thrombosis of the torcular Herophili. Detection at 22 weeks' gestation by ultrasound scan of an anechoic mass located immediately above the tentorium led to magnetic resonance imaging (MRI) being performed at 28 weeks which established the diagnosis of an isolated thrombosis of the torcular Herophili. MRI remained stable throughout pregnancy, and postnatal MRI confirmed the diagnosis at 2.5 months of age. The child is now 16 months old and developing normally.

We report a case of prenatal diagnosis of thrombosis of the torcular Herophili. Detection at 22 weeks' gestation by ultrasound scan of an anechoic mass located immediately above the tentorium led to magnetic resonance imaging (MRI) being performed at 28 weeks which established the diagnosis of an isolated thrombosis of the torcular Herophili. MRI remained stable throughout pregnancy, and postnatal MRI confirmed the diagnosis at 2.5 months of age. The child is now 16 months old and developing normally. Copyright © 2000 John Wiley & Sons, Ltd.