In the past, surgical exploration of the pineal gland was very hazardous. More recently with the aid of the operating microscope and stereotactic techniques direct approach to these tumors has become relatively safe.
A histologic diagnosis should be established whenever possible.
Stereotactic biopsy and third ventriculoscopy would now be regarded as standard of care.
Survival rate is better in biopsied patients.
- Does not appear to affect survival.
- Can be associated with an increased risk of tumor dissemination (positive cytology and VP shunt).
- Aim is to debulk large tumors prior to RT.
- Approach may be occipital transtentorial or suboccipital supracerebellar.
- There are concerns that debulking might be too hazardous and some surgeons may not feel that risks justify the benefits of resection.
Used for mature teratoma, pineocytoma, meningioma and ependymoma.
Different surgical routes:
- Interhemispheric via corpus callosum
- Via dilated right lateral ventricle
- Suboccipital, divide tentorium
- Infratentorial - Supracerebellar (operate with the patient sitting. Incise high occipital to C2. Sample CSF for cytology and markers. Use operating microscope).
Aids diagnosis of lesions of uncertain histology
Decrease intracranial pressure
Increased risk of tumor dissemination
Debulk large tumors prior to radiotherapy
Concerns that this may be too hazardous
Depends on neurosurgeon and their experience in this area
Occipital transtentorial or suboccipital supracerebellar
- mature teratomas
Hazard of surgery itself
Intrahemispheric via corpus callosum
via dilated right lateral ventricle
Suboccipital, divide tentorium