Spinal tumours dealt with in our practice are generally within the dural covering of the spinal cord. They arise from those coverings, the spinal nerves or the spinal cord itself. These tumours occur in isolation as well as in assosciation with conditions such as neurofibromatosis and Von Hippel-Lindau disease. Many of the tumours arise from the same cell which give rise to brain tumours and share names. They tend to present in a different fashion because of their location. The menu bar above links to additional information on the brain tumour pages.
In general spinal tumours are divided into the following groups:
Extradural: Tumours arising outside the dural covering of the nervous system. These are the commonest tumours of the spinal coloumn overall and most often develop in the bone surrounding the spinal canal. They may be primary tumours arising from cells in the spinal bones or from the bone marrow within it. Most are secondaryi> malignant tumours which have spread from a parent tumour elsewhere in the body. Primary tumours may be benign(e.g. osteoid osteoma, osteochondroma) or malignant (chordoma, osteosarcoma). Surgery for these lesions is the preserve of specialist orthopaedic or complex spinal surgeon owing to the frequent need to stabiise the bones of the spinal coloumn afterwards.
Intradural-extramedullary: These tumours arise usually from the dural covering itself (Meningioma) or from the cells forming the outer sheath of the spinal nerves. Less common are benign cysts in the arachnoid later of the meninges (arachnoid cyst) or dermoid cysts (benign growths containing cell types native to the skin). Tumours of the non functional terminal part of the spinal cord - the Filum Terminale- may also be considered in this group e.g. Myxopapillary Ependymoma. If symptomatic these tumours are usually very amenable to removal with a good safety profile. If occurring in isolation then prospects for cure are usually good. Spinal nerve sheath tumours develop in more than 40% of patients affected by Neurofibromatosis type 1 but perhaps only about 2% of those tumours cause symptoms that warrant treatment. For many patients with NF1 watchful waiting with clinical and radiological surveillence is appropriate give the propensity to develop tumours on multiple nerves over time. There is also an 8-13% lifetime risk that a atient with NF1 will develop malignant change in a previously benign nerve sheath tumour.
Intramedullary: This rare group of tumours arise within the spinal cord itself.and may affect bith children and adults. They are notroriously difficult to diagnose given that most of the symptoms they produce may be non specific, slowly progressing and more easily explicable by common, non-tumour pathologies. In children they most commonly present with spinal deformity or loss of function in the extremities. In adults axial spinal or nerve pain is the most common symptom followed by altered sensation or loss of function in the extremities. Examples of the intramedullary tumours encoutered in this practice are:
Surgery for an intramedullary tumour carries significant risks but also too carries the best prospects for short and medium term control of tumours that are causing progressive disability. The surgery serves two functions. firstly to establish the precise nature of the tumour and therefore to direct subsequent managment. The second role is attempted cure or medium term control of the tumour. Some low grade intramedullary tumours (haemangioblastoma, ependymoma) may be completely cured by removal albeit sometimes at the cost of short term neurological worsening. Others which are more diffusely spread within the cord e.g. diffuse fibrillary astrocytoma may not be possible to remove completely but reducing their bulk can be enough to slow the progression of disability significantly.
The images on this page demonstrate and intramedullary ependymoma growing within the spinal cord.
Neurofibromatosis type 1 is a condition which results from a mutation in a gene on chromosome 17. It affects approxomately 1 in 3000 people. The gene is called NF1 and codes for a protein called neurofibromin. It is a tumour supressor gene meaning that when it is not functioning the following can develop:
Patients benefit from genetic counselling and surveillence in specialist clinics designed to identify when adverse features develop in tumours meriting treatment. The nervous system tumours may behave quite benignly. The role of the specialist is as much to prevent unecessary treatment of tumours as to carry out such intervention. Specialist teams are made up of neurologists, neurosurgeons, geneticists, psychiatrists, orthopaedic and plastic surgeons.
Neurofibromatosis type 2 is a genetically and clinically quite distinct disease to the above. It is less common affecting aproximately 1:35000 individuals. All develop vestibular schwannomas and in most these are bilateral. Other tumours assosciated with this condition include schwannomas of other cranial nerves, meningioma and spinal cord ependymoma. The gene mutation in NF2 is on chromosome 22 and its gene prodict is the Merlin protein. Juvenile cataracts may be the earliest detectable evidence of the disease.
Von Hippel-Lindau Disease
Approximately 20% of central nervous system hameangioblastomas occur in patients afffected by Von Hippel-Lindau disease(VHL). This is a condition resulting from mutation of a gene on the shrt arm of chromosome 3. The mutation is inherited in 80% of cases but occurs de-novo in 20%. Someone with a parent harbouring the defective gene will have a 50% chance of inheriting the gene. The disease itself does not usually appear in childhood. Most patients will develop one of its manaifestations by age 40. VHL causes tumours to develop in various locations throughout the body:
Patients with VHL benefit from genetic counselling and from regular screening for the development of new tumours. New tumours developing within the nervous system do not always require immediate intervention. Growth in such haemangioblastomas is not always assosciated with the development of symptoms. Because these tumours exhibit staccato growth were on to operate on every tumour that grew a little on a scan a great deal of unnecessary surgery would result.
Radiosurgery has been advocated as an alternative treatment for intramedullary haemangioblastoma. Long term disease control rates in Von Hippel- Lindau disease have proven inferior to surgerical treatment and the presence of a cyst with the tumour is assosciated with increased treatment morbiditiy.
If you are a patient or carer affected by VHL or Neurofibromatosis please consult our links page for additional sources of information.