Mammoth orbitofrontal neurofibromatosis with herniating meningo-encephalocele.

We are presenting a mammoth orbito-frontal neurofibroma with a herniating meningo-encephalocele in a 23 year old African male. The tumour measured 87cm x 54cm and occupied the right orbito-temporo-facial region and had destroyed the right orbit. A pre operative embolization of the feeding vessels was followed by a one stage near total excision of the tumour and repair of the meningo-encephalocele in hypotensive anaesthesia. The excised tumour weighed 8 Kg and, to the best of our knowledge, is the largest orbito-facial neurofibroma reported in literature.

CASE REPORT

A 23-year-old African male presented to us with a progressively increasing right orbitotemporal mass since birth and associated with headache and neck pain. The mass was extremely disfiguring and significantly interfered with his quality of life [Figures 1 and 2]. He had no history of seizures. Six attempts at excision had been made elsewhere and abandoned because of excessive intraoperative bleeding. Right orbital enucleation was performed at the age of 5 years.

Figure 1

Figure showing the neurofibromatous lesion with extent of facial disfigurement

Figure 2

Figure showing the lesion with torticollis

On examination, he had macrocephaly, with an associated mammoth right orbito-temporo-facial tumour extending down to the level of his right subcostal margin, measuring 87cm x 54cm. He had torticollis, with significant dental malocclusion - a lateral cross-bite. A single area of freckling was present on the abdomen.

Computed tomography scan showed destruction of the right orbit [Figure 3]. Magnetic resonance imaging showed the encephalocele protruding into the neurofibromatous mass [Figures 4 and 5]. The mass was supplied by branches of the external carotid artery, which were embolized before surgery.

Figure 3

Computed tomography scan showing the extent of bony involvement and destruction

Figure 4

Magnetic resonance imaging showing the lesion

Figure 5

Magnetic resonance imaging showing the lesion with encephalocele

The surgery was carried out under hypotensive anaesthesia by a team of combined plastic and neurosurgeons. Per-operative ultrasound was performed to identify the dural sac in the superior aspect of the tumour. An incision was made on the anterior aspect of the tumour to approach the meningo-encephalocele. The skin flap was elevated and the tumour was dissected to expose the dural sac. Dura was seen bulging from the right orbit with the tumour. The dura was incised and excess cerebrospinal fluid was let out to decompress the meningo-encephalocele. Redundant dura was excised and closed by double plication [Figures 6‐8]. Near-total excision of the neurofibromatous mass was performed and the wound was closed in layers. The excised tissue weighed 8 kg. Six units of blood was transfused during the procedure. Postoperatively, the patient developed meningitis, which was successfully treated with medications [Figure 9]. Because there was profuse bleeding even with hypotensive anaesthesia, the bony reconstruction was deferred for the next stage. As there were financial constraints, the patient has not come for follow-up.

Figure 6

Lesion showing pre-operative markings

Figure 8

Immediate postoperative photograph

Figure 9

Patient at discharge

Exposure of the meningo-encephalocele

DISCUSSION

Neurofibromatosis type I (NF-I), formerly known as von Recklinghausen disease, affects about one in 3,000 people. It has an autosomal-dominant inheritance, with complete penetrance, variable expression and a high rate of new mutation. Both Grabb[1] and Nagata [2] used the term "Neurofibromatosa Elephantiasis" to describe appreciably large lesions involving the head and neck region. Less than 1% of the patients suffering from NF-l will have abnormalities of the orbit. [3] Jackson et al. classified orbito-temporal neurofibromatosis into three groups (Group I, orbital soft tissue involvement only with a seeing eye; Group 2, orbital soft tissue and significant bone involvement with a seeing eye; Group 3, orbital soft tissue and significant bone involvement with a blind or absent eye). [4]

A multi-staged surgical approach in orbitotemporal neurofibromatosis excision is necessary in order to obtain optimum aesthetic results. In our case, we were able to perform near-total excision of a neurofibroma weighing 8 kg in one sitting. Excision of the tumour with closure of the associated encephalocele was achieved in a single stage.