Pineal Region Meningioma Surgery

Pineal region meningiomas are rare, deep-seated tumors that present significant surgical challenges due to the surrounding critical neurovascular anatomy.

The pineal region is bordered by vital structures:

• Deep venous system:
  • Internal cerebral veins
  • Vein of Galen
  • Basal veins of Rosenthal
• Brainstem (especially the tectal plate - superior colliculi)
• Thalami and splenium of corpus callosum
• Aqueduct of Sylvius (obstructive hydrocephalus risk)
• Tentorial incisura and straight sinus

Surgical intervention is indicated when:

• The tumor causes symptoms (e.g. hydrocephalus, Parinaud’s syndrome, headaches, ataxia)
• There is progressive growth or mass effect
• Histological diagnosis is required
• The lesion is deemed operable with acceptable risk

Main approaches depending on tumor location and venous anatomy:

Unilateral occipital transtentorial approach (Poppen's approach).

• Occipital transtentorial approach (OTA)
  • Suitable for tumors above the vein of Galen
  • Wide surgical corridor
  • Risk: occipital lobe retraction → visual field deficits

• Supracerebellar infratentorial approach (SCITA)
  • Ideal for lesions below the vein of Galen
  • Less cortical manipulation
  • Patient usually in sitting or park-bench position

• Interhemispheric transcallosal or parietal transventricular
  • Less common
  • Used for tumors extending into lateral ventricles

• Injury to deep veins (especially vein of Galen or internal cerebral veins) → potentially fatal
• Persistent or worsened hydrocephalus
• Visual impairment from retraction or ischemia
• Brainstem injury → ataxia, gaze palsy

• Monitor neurological status and signs of hydrocephalus
• Early postoperative MRI for resection control
• Temporary or permanent CSF diversion (EVD or VP shunt) if needed
• Histological diagnosis (typically WHO Grade I meningioma)

Tip: Detailed preoperative planning with venous imaging (MRV or DSA) is essential to avoid injuring the deep venous system.