Intralesional and subarachnoid bleeding of a spinal schwannoma presenting with acute cauda equina syndrome

Abstract

We present an unusual case of spinal neurinoma with intralesional and subarachnoid bleeding with acute cauda equina syndrome. A 38-year-old man was admitted to our department after a minor thoracic spinal trauma with right lower limb plegia and urinary retention. MRI showed a T11 intradural tumour with intralesional and subarachnoid haemorrhage. The patient was operated of spinal cord decompression and complete tumour resection. The histological examination documented a schwannoma with large haemorrhagic intratumoural areas. A full neurological recovery was documented at 6-month follow-up.

Background

Spinal neurinomas are slowly growing tumours causing radicular pain, paresthesia and/or paraparesis. The incidence of spinal neurinomas in the USA is about 0.26/100 000 people per year.¹ The acute clinical onset of spinal neurinomas may be due to an unusual intralesional bleeding^{2 3} or more frequently to a subarachnoid space haemorrhage (SAH).⁴ In literature, there is a clear predominance of bleeding tumours located in the cauda equina and ependymomas are the most frequent ones followed by neurinomas, meningiomas, haemangioblastomas and gliomas.⁴ We present a rare case of T11 spine schwannoma in a previously asymptomatic young patient who developed severe acute neurological deficits after a minor spinal thoracic trauma. This spinal schwannoma case is relevant for its unusual acute clinical onset due to an intratumoural haemorrhage.

Case presentation

This is the case of a 38-year-old man admitted to our department for progressive right limb monoparesis and acute urinary retention (about 1000 cc) after a minor thoracic spine trauma. The trauma was related to a car accident with no head injury. At admission, the thoracic spine trauma was classified as minor trauma (Injury Severity Score of 3). The medical history of the patient was negative for any relevant disease, including coagulopathies and no antiaggregant therapy had been taken. Before surgery, the coagulation profile was tested, and it resulted normal. The neurological examination documented right leg paresis with L1 homolateral hypoesthesia, urinary retention with preserved anal sphincter tone. Osteo-tendineal reflexes were absent in the affected limb. A thoraco-lumbar MRI showed a right intradural extramedullary lesion at T11 level, with spinal cord compression. Contrastographic enhancement was not obtained due to the patient’s intense back pain and his lack of collaboration (figure 1). The patient underwent urgent surgical procedure of D10-D11-D12 laminotomy. After durotomy, a diffuse SAH with blood clots was observed and a reddish-grey soft tumour attached to a caudal nerve root was documented (figures 2,3). Intratumoural haematoma was removed by gentle suction and the lesion was isolated by sharp microdissection and totally removed. The nerve root adhering to the tumour was partly sacrificed and finally sutured by 8-0 to restore nerve root continuity. The T11 spinous process with epispinous and interspinous ligaments were repositioned by means of titanium plaques and screws. This procedure avoided spinal stabilisation reducing risks of infection and instability.^{5 6} The postoperative CT scan showed the correct realignment of the vertebral column (figure 4) and the postoperative MRI showed complete tumour resection (figures 5,6).

Figure 1.

(A) MRI: T2-weighted schwannoma. (B) MRI: T2-weighted schwannoma.

Figure 2.

Intraoperative subarachnoid bleeding

Figure 3.

Intratumoural bleeding.

Figure 4.

Postoperative CT scan.

Figure 5.

Postoperative MRI study.

Figure 6.

Postoperative CT scan.

Investigations

A thoraco-lumbar MRI showed a right intradural extramedullary lesion at T11 level, with spinal cord compression and mixed intensity within the tumour in the T2-weighted MRI. At macroscopic examination, the lesion presented clear borders with a complete fibrous capsule and large haemorrhagic areas inside. Histological morphology is characterised by spindle cells arranged in bundles or intersecting bundles, without palisade-like arrangements and ‘Verocay’ bodies. The morphology of tumour cells was uniform, with no cell pleomorphism, and a small amount of mitotic figures. Immunohistochemistry revealed a diffuse, positive S-100, CD57 and glial fibrillary acidic protein expression. The Ki-67 proliferation index was less than 10% (figure 7).

Figure 7.

Tumour is encapsulated and consists of cells forming irregular fascicles. Multiple haemorrhagic foci are present (H&E, 10x).

Differential diagnosis

Acute spinal vascular disease.

Treatment

Urgent surgery: laminotomy, tumour resection and recostruction.

Outcome and follow-up

Full neurological recovery was obtained in 6 months by means of a proper rehabilitation program.

Discussion

Spinal neurinomas are slow-growing tumours that rarely cause a rapid neurological deterioration; when it occurs, a haemorrhage should be supposed. Spinal subarachnoid haemorrhage (SAH) often occurs in spinal tumours such as myxopapillary ependymomas, haemangioblastomas, meningiomas, gliomas and finally in spinal neurinomas.^{7 8} Intratumoural haemorrhage in spinal cord schwannoma are rare and a consequent acute neurological deficit may be its first clinical finding.^{8 9} In case of intratumoural bleeding or SAH in patients with spinal schwannoma, literature reports two different theories: the vascular and the traumatic one.^10–12 According to the vascular theory, ectasic and thin vessels of the tumour may undergo thrombosis with tumour necrosis and intratumoural haemorrhage.¹³ The mechanical theory, instead, suggests that traction forces at the interface between the tumour and the surrounding neuronal tissue justified the bleeding of the superficial vascular structure of the tumour capsula; a spinal trauma may cause the acute vascular damage and the bleeding is predominantly localised in the subarachnoid space.¹² In our case, the presence of mixed intensity within the tumour in the T2-weighted MRI (figure 2A,B) was highly suggestive of the presence of blood degradation products inside the tumour related to a recent bleeding episode. The intratumoural haemorrhage was well documented intraoperatively during the tumour resection (figures 3,4). In this patient, the vascular theory may explain the intratumoural bleeding with rapid onset of the cauda equina syndrome. Spinal trauma may be only a ‘contributory cause’ and may be the cause of the SAH. Concerning bleeding risk factors literature reports intratumoural bleeding in alcohol added patients with spinal neurinomas, but in our patient blood coagulation was normal.⁷ This case illustrates a rare intratumoural and subarachnoid haemorrhage of spinal schwannoma. The subarachnoid haemorrhage in spinal schwannoma is a rare condition representing about 1.5% of all SAH1 4 9 13–15 and until now only a few cases have been reported in literature. In our case, our clinical decision to operate as soon as possible was due to the rapid onset of cauda equina syndrome. The laminotomy, with repositioning of laminae and spinous processes by mini-titanium plaques from lamina to articular process, was not essential for spine stability, but when possible we strongly advise restoring the spine integrity especially in young patients. Moreover, the presence of laminae and spinous processes may help dura mater to seal and avoid fistulae. No infection process followed and thanks to our care during the surgery and the use of titanium material. The prompt diagnosis by means of MRI, the decompression and tumour resection allowed the full neurological recovery of our patient.

Learning points.

• Spinal schwannoma rarely causes intralesional bleeding.

• MRI is the gold standard for the diagnosis of thoracic spinal tumour.

• In case of acute neurological deficit, urgent surgery is required to grant any potential neurological recovery.