A bi-foraminal craniometric-guided approach to endoscopic third ventriculostomy and biopsy of a pineal tumour

Background: Pineal tumors are very rarely encountered, with an incidence of <1% of intracranial lesions in adults. Life-threatening hydrocephalus due to obstruction of the third ventricle can result from the location of these tumours. Endoscopic third ventriculostomy (ETV) and tumor biopsy is a safe and feasible strategy, particularly if the tumor appears benign. This mitigates the high risks of uncontrollable venous bleeding from open and stereotactic biopsies. While typically performed using either ipsilateral single or dual bur holes, the location of the tumor may require modifications to the standard endoscopic techniques. Case Description: A 55-year-old male presented with signs of intracranial hypertension and was found to have obstructive hydrocephalus due to a pineal tumour. The tumour displayed a right-sided dominance when the pre-operative imaging was assessed, which would risk forniceal injury if biopsied via a right-sided burr hole. Craniometric measurements revealed a superior trajectory to the tumour via the left foramen of Monro. A biforaminal approach was performed, with a traditional ETV using a right coronal bur hole and biopsy via a left frontal bur hole. This minimized forniceal stretching and allowed a safe biopsy. Conclusion: The bi-foraminal approach has not been widely described in the literature but can potentially avoid morbidity with biopsy in patients with right-sided pineal tumours. We believe this technique should be considered, particularly in low-resource settings where neuroendoscopy is not commonly done, and where the use of ipsilateral single or dual-bur holes may lead to forniceal injury.

Cerebellar Mutism After Pineal Tumour Excision: A Case Report

Cerebellar mutism syndrome (CMS) was first described by Rekate et al in 1985. This syndrome is a common complication of posterior fossa surgery in children with range of 11-29% and usually manifests as diminished speech, hypotonia, and ataxia. The cause is due to bilateral pertubation of the dentate nuclei and their efferent pathways by edema, perfusional defects, axonal damage or metabolic disturbances. Other rare causes of CMS like acute subdural hematoma of the posterior fossa, head injury, brainstem glioma surgery, meningitis and basilar artery occlusion have also been reported. CMS after supracerebellar resection of the pineal tumor is a very rare with very few cases reported. We report such a case in a 10- year old boy who underwent excision of a pineal tumor through the infratentorial supracerebellar route. Key Words: Cerebellar mutism; hydrocephalus; pineal tumor; posterior fossa. DOI: 10.3126/jnps.v31i2.4167 J Nep Paedtr Soc 2010;31(2):124-126

Pineal parenchymal tumours

Chapter 8.9 covers pineal parenchymal tumours, including pineoblastoma (PB), pineocytoma (PC). It also covers the approach to the patient with a pineal tumour