(Images #1 and 2)

(Images 3, 4 and 5)

Click on Images for Enlarged View

Findings: Image #1 is a T2 weighted MR image which demonstrates a heterogeneous primarily cystic appearing mass within the suprasellar cistern. These are focal regions of decreased signal intensity, which may be secondary to calcifications.

Image #2 is an axial T1 weighted image (pre-gad) which again demonstrates a heterogeneous mass within the suprasellar cistern.

Image #3 through #5 are post contrast enhanced T1 weighted axial, sagittal, and coronal images demonstrating extensive, primarily peripheral enhancement with intermixed regions of increased and decreased signal. There is a central region of signal void consistent with calcification. There are cystic regions within high signal intensity on T1 weighted images suggesting high protein contrast. There is obstructive hydrocephalus.

Diagnosis: Craniopharyngioma.

Discussion: Craniopharyngiomas are benign tumors which arise from neuroepithelial rests within Rathke's cleft. They re generally extremely heterogenous tumors composed of intermixed cystic and solid components. There is a bimodal age distribution, with the majority presenting in the pediatric age group while a second peak is found in the 5th decade. Patients generally present with headaches secondary to obstructive hydrocephalus. Patients may also present with diabetes insipidis, growth retardation, or bitemporal hemianopsia. The CT and MR findings are often quite characteristic demonstrating a heterogeneous, cystic and solid lesion located in the sellar/suprasellar region (often with post sellar extension), as well as calcifications. The calcifications are more common in the pediatric age group and may be quite prominent, being present in approximately 80% of cases. The differential diagnosis would include optic glioma, epidermoid, meningioma, and pituitary adenoma, although the characteristic imaging findings often allow relatively accurate differentiation from these lesions.

References:

1. Haaga JR. CT and MR Imaging of the Whole Body.
   Mosby, St. Louis, 1994;1:209-213.
2. Freeman MP. Craniopharyngioma: CT and MR Imaging
   in Nine Cases. Journal of Computer Assisted Tomography.
   1987;11:810-814.
3. Dahnert W. Radiology Review Manual. Williams and Wilkins.
   Baltimore, Maryland;1996:201-202.