Developmental Persistent Falcine Sinus With Cranium Bifidum Occultum, Craniosynostosis, And Associated Anomalies: A Unique Case

The falcine sinus is an intrauterine anatomic structure located in the falx cerebri that is closed after birth and persistenceof this embryologic falcine sinus is considered as a rare variation of the venous pathway which is associated with defect in the development of the straight sinus leading to formation of an alternate venous pathway served by the persistent falcine sinus. Cranium bifidum occultum is another rare skull ossification disorder referred to as the Catlin mark characterized by ossification defects in the parietal bones. Many other associated anomalies can be seen with persistent falcine sinus apart from cranium bifidum occultum which include absent or dysplastic tentorium cerebelli, agenesis of the corpus callosum, apert syndrome, atretic occipital/parietal encephalocele, vein of galen malformation, osteogenesis imperfecta, and chiari malformation Type II. We describe a rare case of a 10-year-old girl who presented with short stature, intermittent headache, and abnormal skull shape. On radiological examination, persistent falcine sinus was detected with large midline skull defect at the high parietal area. The straight sinus was absent, and there was dysplastic tentorium cerebelli. In addition to these, craniosynostosis was also present with many other associated anomalies. Persistent falcine sinus and cranium bifidum occultum are very rare, and when found, they are associated with many anomalies raising the possibility that they may represent the benign end of the same developmental spectrum. To the best of our knowledge, these constellations of anomalies have been reported in very few children.