Gliomas occurring in the sellar region primarily involve the hypothalamus and optic chiasm. Hypothalamic gliomas are tumours of childhood and adolescence, and may extend into the suprasellar cistern. Chiasmic gliomas have a strong association with neurofibromatosis type I when occurring in children. They appear as sharply marginated homogeneous suprasellar masses, clearly separate from the pituitary gland. They are also usually hypointense or isointense with grey matter and may or may not enhance (Fig. 24.18).
Fig. 24.18 Chiasmic glioma: magnetic resonance imaging. Tl-weighted sagittal MR image showing chiasmic glioma displacing mammillary bodies posteriory. Note the normal pituitary gland.
