Aggressive and invasive growth of tectal glioma after surgical intervention and chemoradiotherapy.

A tectal glioma presenting with late-onset aqueduct stenosis and obstructive hydrocephalus is usually categorized as a benign glioma. Apparent clinical or radiological progression justifies biopsy of the tumour. In this case, an unusual tumour shows aggressive and invasive growth after surgical intervention and chemoradiotherapy.