Chordoid Glioma as a Differential Diagnosis of Anterior Third Ventricle Tumours: A Rare Case Report and Five-Year Follow-Up

Chordoid glioma is a rare and relatively recently defined tumour entity. Worldwide there have only been around 90 cases described until now. A chordoid glioma comprises a low-grade suprasellar neuroepithelial neoplasm originating in the anterior part of the third ventricle, with consistent radiological features on MRI. This lesion should be considered as a differential of third ventricle tumours. The patient described in this paper is quite unique in the sense that despite only partial tumour resection was obtained, the residual tumour was not progressive during several years of follow-up. Preoperative recognition of this disease entity is crucial to modify the treatment approach and improve patient outcome.

Surgical management of pineal region lesions

Lesions in the pineal region are topographically located in the centre of the brain in the diencephalic-epithalamic region. An area where the brain is bounded ventrally by the quadrigeminal plate, midbrain tectum, and in-between the left and right superior colliculi, dorsally by the splenium of the corpus callosum, caudally by the cerebellar vermis and rostrally by the posterior aspects of the third ventricle. Major anatomical and surgical challenges are the vein of Galen located dorsally, the precentral cerebellar vein caudally, the internal cerebral veins anteriorly and the basal vein of Rosenthal laterally. Most pineal region tumours can be safely removed by both approaches depending on the surgeon’s experience: the occipital transtentorial approach is recommended in presence of associated hydrocephalus or a steep straight sinus and low location of the tumour and the supracerebellar infratentorial approach for posterior third ventricle tumours.