Persistent falcine sinus in the newborn: 3 case reports of associated anomalies.

The falcine sinus is a normal embryonic structure that is situated between the 2 layers of the falx cerebri and drains the deep cerebral venous system into the superior sagittal sinus. It normally involutes after birth and is uncommon in adults. Although it is often an isolated and incidental finding, it can also be associated with a number of other conditions including but not limited to vein of Galen arterial malformations (VGAM), atretic parietal cephaloceles, acrocephalosyndactyly (Apert syndrome), absence of the corpus callosum, absence of the tentorium, osteogenesis imperfecta, or Chiari II malformations. We present a case series of 3 pediatric patients born with a persistent falcine sinus and an associated condition, including a VGAM, an APC, and a sinus thrombosis. The purpose of this article is to highlight the importance of understanding anatomic variations in the cerebral venous system to help aid in the proper diagnosis and treatment of associated pathologies.