What are skull base chondrosarcomas?
Chondrosarcomas are very rare tumours that occur in the skull base. They arise from cartilaginous remnants that occur between the plates of bone that make up the base of the skull. Due to this origin, they tend to occur in a very particular part of the skull base, which in turn leads to characteristic presenting symptoms related to nerves that are in this region. Specifically, these nerves control eye movements and facial sensation and, therefore, double vision or abnormalities of facial sensation are characteristic presenting symptoms.
How is the management of chondrosarcomas decided?
Chondrosarcomas tend to behave in a very benign fashion. In other words, they are slow growing but will inevitably gradually enlarge and cause problems with surrounding structures as described above. As a result, an aggressive treatment policy is usually called for which characteristically will involve both surgery as well as a specialised form of radiotherapy, namely proton beam radiotherapy.
The surgeons in the Brain and Spine Clinic have considerable experience in dealing with this very rare tumour and are able to draw on the expertise of a Skull Base Multidisciplinary Team (MDT) in formulating an individualised management plan for you. This team holds fortnightly meetings at Salford Royal Hospital, with a team of experts with a huge combined experience of managing such problems. Your surgeon will convey the outcome and recommendations of this meeting to you.
What are the treatment options?
Chondrosarcomas are in some ways similar to chordomas, described elsewhere in this website. Like chordomas, they arise from the skull base and invade it. Generally speaking, the principles of treatment are the same as those for chordomas, namely maximal surgical resection followed by a specialised form of radiotherapy, proton beam radiotherapy. The treatment requires highly specialised and individualised care by experts in the field. The surgery falls within the subspecialty area of neurosurgery called skull base surgery in which Andrew King and Scott Rutherford have great experience and expertise.
The principal of surgery is to achieve maximal resection, in other words to remove as much of the tumour as is safely possible. Because the tumour arises from the skull base, it is often involving the cranial nerves that leave the brain through the base of the skull and supply the head and neck as well as the spinal cord and blood vessels both supplying blood to the brain (arteries) and draining blood from the brain (veins and venous sinuses).
The surgery is technically challenging both in terms of access to the tumour and its surgical removal. It usually involves a combined team of neurosurgeons and skull base ENT and the surgeons of the Brain and Spine Clinic routinely work in such a team. Once surgical resection has been achieved, consideration is given to post-operative radiotherapy usually in the form of proton beam radiotherapy, which is described more fully in the chordoma section. It would be fair to say that given that chondrosarcomas are usually less aggressive tumours than chordomas, there is more of a decision to be made about the need for proton beam radiotherapy afterwards and occasionally a decision is made after successful surgical resection to simply monitor with serial scanning rather than proceeding directly to radiotherapy. This decision will invariably be individualised to the patient and will be part of the discussion management when you come to see your neurosurgeon.