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

Pathogenesis and treatment of a giant occipital bone defect with meningoencephalocele in an NF1 child: case report and review of the literature

Autosomal dominantly inherited neurofibromatosis type I (NF1) is a systemic disorder caused by a mutation of a gene on chromosome 17q11.2 and characterized by multiple café-au-lait spots, lentiginous macules, Lisch nodules of the iris, and tumors of the nervous system. Bony manifestations such as scoliosis, dysplasia of the greater sphenoidal wing, tibial pseudoarthrosis, short stature, and macrocephaly have been reported in approximately 50% of patients. However, calvarial bone defects are rare. After screening 324 articles, 23 cases (12 adult and 11 pediatric patients) of occipital bone defects in NF1 patients were selected. All patients had a single/multiple bone defect over the lambdoid suture. Adjacent benign plexiform neurofibromas were observed in 14 patients (60.8%, 7 adults and 7 children); one adult patient was diagnosed with neurofibrosarcoma. Meningoencephalocele over the occipital defect was noted in 8 cases (34.78%, all adults). Cranioplasty was performed in only 17.39% of patients. Histologic examination was performed in 7 of the 15 patients with associated neurofibromas/neurofibrosarcomas. Biopsy of the bone margins surrounding the defect was performed in only one case. Pathologic examination of the herniated parieto-occipital or cerebellar tissue was not performed in any of the patients studied. We report the case of a 9-year-old girl with NF1 and a significant occipital bone defect and performed a systematic review of the relevant literature to highlight the challenges in treating this condition and to investigate the underlying mechanisms contributing to bone defects or dysplasia in NF1.

Dural Ectasia in Neurofibromatosis 1: Case Series, Management, and Review

BACKGROUND

The natural history and management of dural ectasia in Neurofibromatosis 1 (NF1) is still largely unknown. Dural ectasias are one of the common clinical manifestations of NF1; however, the treatment options for dural ectasias remain unstudied.

OBJECTIVE

To investigate the natural history, diagnosis, management, and outcome of the largest case series of patients with NF1-associated dural ectasia to date.

METHODS

Records from our NF1 clinic were reviewed to identify NF1 patients with computed tomography or magnetic resonance imaging evidence of dural ectasia(s) to determine their clinical course. Demographics, symptoms, radiographic and histopathologic findings, treatment, and clinical course were assessed.

RESULTS

Thirty-four of 37 patients were managed without surgery. Of the 18 initially asymptomatic patients, 5 (27.8%) progressed to symptoms attributable to a dural ectasia (onset of 2.7% per patient-year). Three patients required surgical intervention because of extraspinal mass effect. All 3 initially improved but had symptom recurrence within 2 yr. Reoperation involved shunt placement for cerebrospinal fluid (CSF) diversion. On imaging review, 26 (76.5%) of the nonsurgical patients harbored an associated nearby plexiform neurofibroma. Pathology of one surgical case revealed dural infiltration by diffuse neurofibroma.

CONCLUSION

Using the largest NF1-associated dural ectasia group to date, we report the first symptom-onset rate for nonsurgical patients. In the few cases requiring surgery for decompression, primary resection, and patching of ectasias failed, subsequently requiring CSF shunting. We demonstrate imaging evidence of nearby plexiform neurofibroma in a majority of cases, which, when combined with histopathology, provides a novel explanation for the formation of dural ectasias.

Repair of Occipital Bone Defects in Neurofibromatosis Type 1 by Means of CAD/CAM Prefabricated Titanium Plates

Certain skeletal defects may develop in neurofibromatosis type 1 (NF1), a common tumor-suppressor syndrome, such as cranial lesions confined to the lambdoid suture region. Here, we report on the repair of osseous defects of occipital bone in a NF1 patient with history of skull trauma and tumorous hemorrhage. Computer-aided design and computer-aided manufacturing (CAD/CAM)-assisted devices were applied to safely close the bone defects. The variable phenotype of NF1 in the occipital skull region is discussed and a brief review is presented on NF1-related therapies for tumors and malformations of the occipitoparietal skull region.

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.

Jugular foramen meningocoele in a patient with neurofibromatosis type 1

Objective:

We present a rare case of a jugular foramen meningocoele in a 48-year-old female, with neurofibromatosis type 1, presenting with positional vertigo. We also postulate possible underlying pathophysiological mechanisms.

Method:

We describe the imaging findings of this rare entity and review the literature on skull base meningocoeles, particularly in the context of neurofibromatosis type 1.

Results:

A computed tomography scan revealed smooth expansion of the jugular foramen. Magnetic resonance imaging showed a fluid filled lesion expanding the jugular foramen and communicating with cerebrospinal fluid of the cerebellomedullary cistern superiorly.

Conclusion:

Skull base meningocoeles are a rare entity and we believe that this is the first reported case of a meningocoele causing enlargement of the jugular foramen in a patient with neurofibromatosis type 1. The meningocoele may have resulted from a severe form of dural ectasia or from dysplastic, weakened bone at the skull base.

An unusual post-traumatic occipitocervical pseudomeningocele: case report

BACKGROUND

A rare case of massive post-traumatic subcutaneous pseudomeningocele probably communicating with the cisterna magna, is reported.

CASE DESCRIPTION

An 8-year-old boy sustained a severe injury to the nape of the neck, after which he developed a huge local subcutaneous swelling containing cerebrospinal fluid (CSF). Communication of the subcutaneous CSF collection with the cisterna magna or any other site of dural fistula could not be identified. After a lumbo-peritoneal CSF shunt, the swelling resolved completely.

CONCLUSION

The clinical features of a rare case of symptomatic post-traumatic cerebrospinal fluid pseudomeningocele are elaborated.

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.