Dural ectasia as a cause of widening of the internal auditory canals in neurofibromatosis

Significance of surgical treatment for severe dystrophic changes in the cervical spine associated with neurofibromatosis type I: a case report

There have been several reports about the treatments for dystrophic changes in the thoracic or lumbar spines owing to neurofibromatosis type-1. However, dystrophic changes in the cervical spine have been rarely reported. In this study, we present the case of a 13-year-old boy with severe dystrophic changes (dural ectasia) in the cervical spine owing to neurofibromatosis type-1. Although he had no neurological deficit, imaging studies revealed cervical kyphotic deformity and osteolysis of vertebral bodies. Thinning of vertebral bodies and laminae from C2 to C5 was remarkable, suggesting that the patient was at risk of suffering a spinal injury. The patient underwent cervical posterior fusion. At the 2-year follow-up examination, there was complete posterior bony fusion and no obvious progression.

Calvarial defects associated with neurofibromatosis Type 1

Calvarial osteolysis is a relatively rare finding in patients with neurofibromatosis. The authors describe two patients with neurofibromatosis Type 1 (NF1) and extensive cranial defects associated with underlying dural ectasia. Cranioplasties were performed in both patients with mixed results. One patient underwent cranioplasty using titanium mesh and methylmethacrylate. The other patient underwent an extensive cranioplasty with autogenous iliac crest grafting, and after initial healing has since had further bone resorption. In conclusion, the results of cranial reconstruction in patients with NF1 and dural ectasia are unpredictable because of the tendency for further bone resorption; techniques that protect the graft material from cerebrospinal fluid pulsations via a rigid mesh should be considered.

An unusual pterygopalatine meningocele associated with neurofibromatosis type 1. Case report

The authors describe an unusual meningocele of the lateral wall of the cavernous sinus and the anterior skull base in a young patient with typical stigmata of neurofibromatosis Type 1 (NF1). This lesion was discovered during evaluation for recurrent meningitis. It represented an anterior continuation of Meckel's cave into a large cerebrospinal fluid space within the lateral wall of the cavernous sinus, extending extracranially through an enlarged superior orbital fissure into the pterygopalatine fossa adjacent to the nasal cavity. It was successfully obliterated, via an intradural middle fossa approach, with fat packing and fenestration into the subarachnoid space. This meningocele most likely represents a variant of cranial nerve dural ectasia occasionally seen in individuals with NF1. It has as its basis the same mesodermal defect responsible for the more common sphenoid wing dysplasia and spinal dural ectasias identified with this condition. Involvement of the trigeminal nerve with expansion of the lateral wall of cavernous sinus has not been reported previously. The authors surmise, however, that it may be present in some cases of orbital meningocele associated with sphenoid wing dysplasia.

Suboccipital meningocele presenting as a huge retropharyngeal mass in a patient with neurofibromatosis Type 1. Case report

The authors report an extremely rare case of neurofibromatosis Type 1 (NF1) with a suboccipital meningocele presenting as a huge retropharyngeal mass. A 73-year-old woman with typical cutaneous manifestations of NF1 presented with nasal obstruction and dysphagia due to a retropharyngeal mass. Magnetic resonance imaging revealed a huge mass lesion extending from the right occipital bone defect to the retropharynx through the right paravertebral region. Computerized tomography scanning after intrathecal administration of contrast material confirmed that the mass was a meningocele protruding through a right occipital bone defect. The authors attempted to ligate this meningocele, most of which was excised via a suboccipital approach, but a second transcervical operation was required. Finally, the meningocele resolved and the patient was discharged without symptoms.

Neurofibromatosis type 1: pathology, clinical features and molecular genetics

Neurofibromatosis type 1 (NF1) or von Recklinghausen neurofibomatosis, is a common heritable neurocutaneous disorder. This disorder appears to affect all races, with a prevalence estimated to be 1 in 3000. Approximately half of all cases of NF1 represent new mutations. The characteristics of NF1, which include cafe-au-lait spots, neurofibromas, Lisch nodules, optic glioma, osseous lesions, macrocephaly, short stature and mental retardation suggest that the genetic lesion affects the proper development of multiple organ systems. Within the past few years, the gene causing NF1 has been identified and the protein encoded by this gene, neurofibromin, has been the subject of detailed investigation. The NF1 gene spans over 350 kb of genomic DNA and encodes a protein product of 2818 amino acids. Neurofibromin is expressed in many different tissues. It is now known that one role of neurofibromin is as a GTPase activating protein (GAP), very likely in the same pathway of signal transduction as ras. Absence of neurofibromin in mice homozygously mutant for the NF1 gene results in profound developmental abnormalities. In mice that are heterozygous for NF1, an accelerated onset of tumor formation is observed. Combined with studies of tumors from NF1 patients showing homozygous deletions in the NF1 gene, these data suggest a role for NF1 as a "tumor suppressor". Evidence suggesting other roles played by neurofibromin, in control of proliferation in some situations and differentiation in others, is gradually bringing the previously hazy picture of this genetic disorder into sharper focus.