Tectal plate gliomas. Part II: CT scans and MR imaging of tectal gliomas.

CT scans and MR images were analyzed in 12 patients with histologically proved tectal plate gliomas. In an attempt to identify the nature of these lesions, their radiological characteristics were correlated with the histological results. In four of our patients CT scan failed to show the tumour. MR imaging demonstrated the tectal distortion in all cases. Contrast enhancement, calcification, cystic portions, exophytic nature were observed in both high and low-grade gliomas. We conclude that in the case of intrinsic tectal tumours, the most probable diagnosis is that of low-grade astrocytoma while in the case of exophytic tectal tumours, the differential diagnosis from pineal region tumour is required and a histological verification is necessary.