This sagittal T1-weighted MR image shows a suprasellar lesion in a 12 year-old boy. There is a fat-containing area and a cystic area. There was minimal soft tissue component. The lesion expanded and remodelled the sella, without bone erosion. There is elevation of the optic chiasm, and the pituitary can be seen compressed into the base of its fossa.

The lesion was biopsied. There were epithelial elements, underlying connective tissue with sebaceous glands, and fat, consistent with a mature teratoma. There were no immature or malignant components.
Intracranial teratomas are midline tumours which may contain calcium, soft tissue, cysts and fat. They occur from the optic chiasm to pineal regions. They may be mature, immature or malignant, depending on the degree of differentiation. Differential diagnoses include craniopharyngioma, dermoid and non-germinoma germ cell tumour.
Reference: Osborn A. Diagnostic Imaging: Brain Amirsys 2004

Credit: Dr Laughlin Dawes