An unusual case of hydranencephaly presenting with an anterior midline cyst, a posterior calcified mass, cerebellar hypoplasia and occlusion of the posterior cerebral arteries.

We present an unusual case of severe hydranencephaly in a term infant who presented with the following additional unique features, which were discovered on CT, MRI and MR angiography examinations: (1) occlusion of the bilateral posterior cerebral arteries, (2) absence of the occipital lobes, (3) an ovoid calcified mass sitting on the inner table of the occipital bone, (4) severe cerebellar hypoplasia, (5) a dysmorphic cystic diencephalon, (6) a large anterior midline cyst just above the cribriform plate and (7) absence of the falx. These imaging findings were confirmed at autopsy.