Growing traumatic leptomeningeal cyst of the roof of the orbit presenting with unilateral exophthalmos

BACKGROUND Growing skull fractures rarely develop in the skull base region. To the bes t of our knowledge, only two similar cases have been reported in the Englis h literature. This rare complication, which can occur even after a mild hea d injury, can produce exophthalmos and threaten the vision. METHODS The clinical and radiological findings of expanding leptomeningeal cysts ex tending into the orbit in nine patients referred to the department of Neuro surgery are presented. After appropriate investigations confirming the pres ence of the expansile retroglobal lesion, surgical exploration was performe d via fronto-lateral or the preferred fronto-basal approach. The variable f indings are denoted and the relevant literature is also reviewed. RESULTS Frontobasal head injuries play an important role in pathogenesis of these t raumatic expansile leptomeningeal cysts. In this series of nine young girls , 6.65% (six out of nine) injuries happened in the first decade of life wit h an interval of 2 to 12 months (mean = 6.7, SD = 9.7). High-resolution cor onal view computed tomography (CT) scanning with bone density window images , and high intensity cystic lesions visible on T2-weighted coronal MR image s were diagnostic clues. CONCLUSIONS Growing fractures of the anterior skull base may complicate the natural cou rse of healing of any minor frontobasal head injury, especially during chil dhood. Good quality imaging is mandatory in cases of progressive unilateral exophthalmos. Proper surgical intervention will lead to a good cosmetic re sult. (C) 2000 by Elsevier Science Inc.