Journal of Dr. NTR University of Health Sciences

CASE REPORT
Year
: 2016  |  Volume : 5  |  Issue : 3  |  Page : 222--225

A rare case of neurofibromatosis type 1


Vijaya Prasad Balda, Siva Rama Krishna, Satyavaraprasd Kadali 
 Department of Neurosurgery, Andhra Medical College, King George Hospital, Visakhapatnam, Andhra Pradesh, India

Correspondence Address:
Vijaya Prasad Balda
Department of Neurosurgery, Andhra Medical College, King George Hospital, Visakhapatnam, Andhra Pradesh - 530 002
India

Abstract

Neurofibromatosis type 1 disease is characterized by pigmented cutaneous lesions and generalized tumors of neural crest origin. Sphenoid dysplasia is one of the characteristics of this syndrome which occurs in 5-10% of the cases. However, complete sphenoid wing agenesis is rare. Traditional surgical treatment of sphenoid dysplasia involves split bone grafting and repair of anterior skull defect. However, the results of this procedure may not be entirely sustainable owing to bone graft resorption and recurrence of proptosis and pulsating exophthalmos. We report here a rare case of neurofibromatosis type 1 disease with associated absence of sphenoid wing, for which the newer method of reconstruction with titanium mesh was employed by intracranial approach.



How to cite this article:
Balda VP, Krishna SR, Kadali S. A rare case of neurofibromatosis type 1.J NTR Univ Health Sci 2016;5:222-225


How to cite this URL:
Balda VP, Krishna SR, Kadali S. A rare case of neurofibromatosis type 1. J NTR Univ Health Sci [serial online] 2016 [cited 2020 Jan 23 ];5:222-225
Available from: http://www.jdrntruhs.org/text.asp?2016/5/3/222/191849


Full Text

 Introduction



Neurofibromatosis type 1 is a relatively common autosomal dominant disorder that occurs in one in 3500 live births.[1] Fewer than 1% of patients with neurofibromatosis type 1 are reported to have abnormalities of orbit.[2] Usually, this manifestation occurs unilaterally and is often associated with plexiform neurofibromas in the distribution of trigeminal nerve.[3] Although sphenoid dysplasia occurs in 7-12.8% of patients with neurofibromatosis type 1, the absence of a sphenoid wing is very rare.[4],[5],[6],[7] We report a rare case of neurofibromatosis type 1 with absence of sphenoid wing, for which reconstruction with titanium mesh was done by intracranial approach.

 Case Report



A 10-year-old boy was brought to hospital with complaints of protrusion of right eyeball and diminished vision of right eye from the last 2 years [Figure 1]a. History revealed that protrusion was progressively increasing from 2 years and the diminishing vision was painless and progressive in nature from 2 years [Figure 1]b. Physical examination revealed seven café-au-lait spots of size 10-15 mm over his chest, abdomen, left hand, and face [Figure 1]c. Plexiform neurofibroma in the right upper eyelid causing ptosis was present. An ophthalmic examination revealed presence of pulsatile exophthalmos in the right eye. Vision of counting fingers from 1 feet was present in the right eye. Left eye was normal. Lisch nodules were present in the iris of right eye. Fundus examination showed cup disc ratio of 0.8. Family history revealed that patient's father was having multiple hypopigmented patches (café-au-lait spots over his chest, abdomen, and face) and painless swellings (neurofibromas), consistent with neurofibromatosis type 1 [Figure 1]d. Patient was investigated radiologically with CT scan brain with 3-D reconstruction and MRI brain. Investigations revealed absence of right greater and lesser wings of sphenoid with herniation of right temporal lobe into the orbit [Figure 2]a. There was also retroorbital mass which, along with right temporal lobe, compressed the right optic nerve [Figure 2]b. Arachnoid cyst is present in right temporal lobe. Right extended pterional craniotomy was done and by extradural approach, the defect was identified. There was absence of greater and lesser wings of sphenoid with herniation of right temporal lobe into right orbit. There was also a firm retroorbital mass which was excised and sent for biopsy. Right temporal lobe was retracted from the orbit and sphenoid wing defect was repaired with titanium mesh [Figure 3]. Durameter was opened and arachnoid cyst in the right temporal lobe was excised, which led to decreased volume of the right temporal lobe and, thus, it fit into middle cranial fossa. The patient's postoperative course was uneventful. Biopsy of retrobulbar mass showed features of neurofibroma [Figure 4]. His exophthalmos and vision had improved [Figure 5].{Figure 1}{Figure 2}{Figure 3}{Figure 4}{Figure 5}{Figure 6}{Figure 7}{Figure 8}{Figure 9}

 Discussion



Neurofibromatosis type 1 is a hamartomatous disorder that originates in the neural crest and secondarily affects the supporting mesenchyme. It can affect all systems of the body. Sphenoid dysplasia is one of the characteristics of neurofibromatosis type 1, occurring in 5-10% of cases. Complete dysgenesis of the sphenoid wing is very rare.[4],[5],[6],[7] There are still many controversies regarding the origin of this sphenoid bone dysplasia in neurofibromatosis. Although it has been regarded as a developmental anomaly of mesodermal origin, the exact mechanism is uncertain. An abnormality in the skull and orbital development, altered transmission of cerebrospinal fluid pulsations, and interaction between plexiform neurofibroma and sphenoid bone are postulated as possible mechanisms.[5] In our case, there was no plexiform neurofibroma in the brain, but the sphenoid bone defect was present. Review of literature revealed this greater wing defect is not congenital. It may progress and eventually become typical sphenoid bone dysplasia.[8] When the greater wing defect is sufficient to allow the temporal lobe to herniated into the orbital cavity, it may appear as an exophthalmos and gross facial deformity.[9],[10] The greater wing defect is corrected for both cosmetic and functional reasons. Surgical correction can be performed through an intracranial approach or lateral orbital approach, but the intracranial approach is associated with a high complication rate. Traditionally surgical treatment of sphenoid dysplasia involves split bone grafting and repair of the anterior skull base defect. However, the results of this procedure may not be entirely sustainable owing to bone graft resorption and recurrence of proptosis and pulsating exophthalmos. A new method involves using a titanium mesh in conjunction with bone graft to act as a barrier between the orbit and the middle cranial fossa.[11] We report here a rare case of neurofibromatosis type 1 disease with associated absence of sphenoid wing, for which the newer method of reconstruction with titanium mesh alone without bone graft was employed by intracranial approach. On follow-up, the patient showed improvement in exophthalmos without recurrence.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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