A 56 year old lady had a two year history  of neck pain with radiation to right shoulder and arm since 1999. She felt weakness and numbness over  the medial two fingers of the right hand   since the last 15 days.  There was no history of trauma or constitutional symptoms. She had taken treatment in the form of analgesics from a local doctor with temporary relief of pain. Neurological examination revealed weakness of the right deltoid, biceps and extensors of the left wrist.
Clinical examination revealed tenderness at C-4,5,6 region associated with  paraspinal muscle spasm and restriction of neck movements.The blood parameters were within normal limits.

As the mass was eroding C5 vertebral body with impending collapse, and there was a predominant C-5 nerve root compression clinically as well seen in the MRI, it was decided to excise the tumour and stabilise the spine.

Pre operative planning included staging of the tumour according to the WBB classification which showed that the tumour extended from the 7th- 9th quadrant  position. In this patient , spinal instability derived from bone destruction by the tumour seemed to cause severe neck pain with radiation to the right upper limb and also neurological deficit therefore  it was planned to do a  staged anterior and posterior resection of the tumour and  decompression of the cord.  Surgery in the first stage included excision of the tumour and posterior stabilisation wth plates and screws.Posterior stabilisation from C3-C7 was done with plates and screws.  Laminectomy of   C4,5,6 was done .A  large tumour mass which was encapsulated, but destroying the posterior structures of the C-4,5and 6 on the right side was removed.

Tumour exposed through posterior approach

The second stage included tumour excision, C-5  corpectomy and reconstruction with a iliac bone graft and anterior stabilisation with a titanium plate.  Intra operative findings showed a sausage shaped tumour mass extending into the C4,5 foraminal space and ensheathing the  C4 nerve root.  The tumour mass could not be completely visualised by the conventional approach used in anterior cervical spine surgery by developing a plane between the vessels and the trachea and oesophagus.So the tumour was approached by devoloping a cleavage plane by retracting the neurovascular bundle medially.  The thin shell of the anterior part of the lateral mass of the C-5 was excised, corpectomy done and the tumour followed into the foramen and excised along with its capsule. Anterior stabilisation was done by a titanium plate between C4 an C6 and the use of  a cortico cancellous iliac crest graft between the curetted end plates C4 and C6.
 

Anterior approach to the tumour lateral to the neurovascular bundle.

Sausage shaped tumour dissected

Stabilisation by anterior titanium plate and screws.

 

Histopathological examination study showed extensive antony B areas with heamoragic necrosis indicating a schwannoma. The post operative course  was uneventful except for episode of hypokalaemia which was promptly  treated. Patient made  good post operative recovery and was mobilised on the fifth post operative day in a philadelphia collar.The patient did not  have any clinical disability due to the loss of C4 nerve root.

Post operative X-ray showing  anterior and posterior  stabilisation by plate and screws.

Discussion
An accurate pre-operative diagnosis was difficult in this case but the scalloping of the vertebral body suggested a long standing etiology which was probably benign. The large area of destruction starting from the C4-5 foramen with scalloping suggested a nerve sheath tumour. Complete excision is recommended for this locally aggresive benign tumour because inadauquate removal has a has a risk of recurrence , which requires more definite , difficult , and dangerous surgery at a later date.( Santi MD etal . Total sacrectomy for for a giant sacral schwannoma. A case report. Clin orthop 1993;294:285-9.)Irradiation was not give to this patient, because it is unknown wheather  irradiation is effective for benign schwannomas an recurrence after removal is rare irrespective of the irradiation.

Nerve sheath tumours have a 35 % incidence in the 4th to 6th decade.  The two intra dural types seen are the primary intra cranial and the spinal types.  50% of these affect the thorasic cord.  Cervical cord involvement is the next most frequent.  They originate from the schwann cells that invest the nerve root as it exits the spinal coloumn. (Merck manual, secs.14, chapter 183 "Disorders of curvical cord.").

These slow growing benign tumours can grow suddenly and cause acute severe pain and neurological deficit due to heamorage.  Complete surgical excision is the treatment  and has excellent neurological recovery. (Indian peadiatrics Journal, Editorial Feb 2001).