Leptomeningeal cyst: nonenhanced and enhanced computed tomography findings.

Leptomeningeal cyst (a growing fracture of childhood) is well recognized as a rare complication of traumatic skull injuries. The clinical and plain roentgenogram findings have been described previously in the literature. These fractures are commonly associated with encephalomalacic changes of the underlying herniated brain tissue that occurs as part of the pathophysiology of leptomeningeal cyst formation. This is a case report of a leptomeningeal cyst with peripheral enhancement of the herniated issue most likely representing the pia mater, and/or development of a highly vascularized pseudodura. The computed tomography findings pre and postcontrast of a growing fracture of childhood have not been previously reported.