Lumbosacral dural anomalies in von Recklinghausen neurofibromatosis.

The lumbosacral dural abnormalities in two patients with von Recklinghausen neurofibromatosis (vRNF) are described. Analysis of 18 previously reported cases revealed considerable morphological variations of the lumbosacral dural lesions associated with vRNF, but three basic forms may be distinguished. The pathogenesis of these lesions is still controversial. The contrast studies in our patients, especially the computed tomographic myelography (CTM), suggest that the meningocoeles in vRNF are, in fact, abnormally dilated and elongated nerve root sleeves and should, therefore, be distinguished from other types of meningeal cysts occurring in the lumbosacral region. The clinical significance of these dural anomalies are discussed.