Craniopharyngioma (MRI/CT)	

Craniopharyngiomas are benign neoplasms which may arise from epithelial remnants of Rathke's pouch. They are the most frequent neoplasm in the sellar region in children and young adults. A second peak also occurs in adults at around the fifth decade. These tumours usually arise in the suprasellar region, however, they may be both suprasellar and intrasellar, or entirely intrasellar. Craniopharyngiomas are radiographically heterogeneous in appearance, often containing cysts and globular calcification (Fig. 24.15). The cystic portions of the mass may appear hypointense on Tl-weighted MR images, and hyperintense on T2-weighted images.

Fig. 24.15 Craniopharyngioma. Balanced-weighted coronal MR image (a) showing a cystic area and high intensity signal area in a large sellar/suprasellar mass, typical of craniopharyngiomas. Characteristic globular calcification is easier to identify on a coronal CT image (b) of the same patient.