Ganglioneuroma is a rare disease with nonspecific clinical manifestations and is difficult to diagnose before operation. The differential diagnosis was mainly with other neurogenic tumors [10–13]. The patient developed symptoms when she was 4 years old. The early onset was more consistent with ganglioneuroma, as schwannoma and neurofibroma are more common in adults [10, 13]. The MRI scans of the patient showed low intensity on T1 images and heterogeneous high intensity on T2 images (Fig. 2). The features on T2-weighted images correlated with ganglioneuroma. The appearance is presumed to be caused by a combination of ganglion cells [1, 2, 14]. This patient’s interverteberal foramens between L1-2 and L2-3 were widened which was consistent with ganglioneuroma, as schwannoma and neurofibroma rarely invaded more than one foramen [8, 13]. Schwannoma was a benign tumor arising from the sheath of the spinal nerve roots [15], and this tumor arose from sympathetic ganglia. The diagnosis of ganglioneuroma was confirmed by histology.
In multiple or huge tumors, complete resection at all sites is very difficult. Thus subtotal or partial resection can be an acceptable choice [2, 3]. The purpose of the surgery is to decompress the spinal cord because the paraspinal part of the tumor is usually asymptomatic. Although subtotal resection has been proved to be beneficial in this situation, it is a general agreement that total resection is the best option for symptomatic solitary ganglioneuroma and the long-term prognosis is very good [1, 4, 8]. The role of radiotherapy and chemotherapy are limited to the treatment of ganglioneuroma due to their benign biological nature [4, 16].
There are various surgical approaches for managing spinal ganglioneuromas [1, 2, 4, 8, 17]. A combined posterior-posterolateral approach was used to remove the intradural and extradural parts of tumor extending through the foramina [8]. Pang et al. described a combined anterior and posterior approach in entirely removing a lumbosacral ganglioneuroma. The technique was used to treat a 36-year old female patient, and was performed by the general surgical, neurosurgical and orthopaedic team [4]. The combined approaches were technically challenging, and the potential morbidity and mortality were associated with these large resections [17]. In this case, despite the large tumor size, total resection was achieved by a single posterior approach. The posterior approach provided the surgeon with a familiar orientation of all intraspinal structures and left the patient with only one wound. The tumor was localized in epidural extending to the retropleural space. The vertebral body, bilateral pedicles and facet joints were eroded by the tumor, and the bone destruction provided an exposure of part of the tumor. Further transversectomy and facetectomy greatly improved the visibility of the tumor. With the procedure of the tumor resection piecemeally, the tumor was totally exposed and finally excised completely. In conclusion, the posterior approach may be a useful method for removing spinal ganglioneuroma.
Spinal ganglioneuromas often involve the nerve roots [1–4]; sacrifice of the entire spinal nerve is usually required for a total resection. In the study of Kim [15], 15 patients had large schwannomas with extradural components, which necessitated sacrifice of the entire motor and sensory radix. It was found that 11 (76 %) of these 15 did not develop any deficits referable to the involved myotome or dermatome. Some studies indicate that risks of causing disabling neurological deficits after sacrificing these roots are small [15, 18]. Regarding ganglioneuromas, there is no correlative literature. In this case, the tumor involved the entire left L1and L2 nerves diffusely, including motor and sensory roots. It is impossible to remove the tumor without sacrificing the affected nerve roots. During the operation, no motor responses were noted with stimulation of the tumor or of the lateral roots. The entire left L1and L2 nerve roots and two involved distal nerves were resected together with tumor. After the surgery, the patient had slight deterioration of the muscle strength in left leg from grade 4 to 4- withthe decreased sensations remained unchanged. The weakness was expected due to L1 and L2 nerve roots resection. The effect of weakness was small or non-existent. She was ambulating independently at discharge and the strength of both lower limbs completely recovered within 12 weeks. It was suggested that the incorporated nerves were no longer functional at the time of surgery thus sacrificing the nerve roots would not cause disabled neurological deficit.
There are sporadic reports that ganglioneuromas may cause painless progressive spinal deformity [5, 10, 14]. The proposed mechanism for the scoliosis is the tumor expansion to the nerve root and resultant destruction of the lateral and anterior vertebral elements [5, 19]. Ganglioneuromas can grow to huge size while remaining asymptomatic and mimic the idiopathic scoliosis of adolescent. The treatment for this entity consists of complete surgical resection of the tumor and correction of the deformity; the outcome is usually highly positive [14]. In this case, the tumor involved the vertebral body, bilateral pedicles and facet joints, which leaded to spinal instability. This patient already had mild scoliosis as a result of bone destruction and pain. Although laminectomy, facetectomy and transversectomy provided a good exposure of the tumor, the spinal instability was aggravated. The fixation and fusion were necessary. Because some pedicles were eroded, the pedicle screws were applied at the levels of T10–T12, L4 and L5, and a crosslink was placed to increase the rigidity of the structure. The multisegmental posterior instrumentation and reconstruction addressed all elements of the 3-column spinal stability principle [20], and showed a favorable result. Multiple level laminectomies may cause spinal instability in the long term, however fusion or laminoplasty can enhance stability to the spine [8, 20]. In some cases of severe scoliosis or facetectomy, spinal instrumentation and fusion may be needed.
