Supratentorial primary intra-axial tumors in children. MR and CT evaluation.

Purpose: To evaluate the MR and CT features of pediatric supratentorial intra-axial tumors with respect to differential diagnosis and the role of each investigation modality.
Material and Methods: MR and CT findings in 40 children with 12 types of pathologically proven histological tumors were reviewed.
Results: The location of tumors might be one clue to differential diagnosis. In our material, cysts (60%), calcifications (45%), and intratumoral hemorrhages (27%) were found in the tumors. Characteristic features noted in some lesions included: peritumoral hemosiderin deposition in cavernous angiomas; intratumoral flow void in a choroid plexus carcinoma and in glioblastomas; and hemicerebral atrophy in germinomas. A comparison between malignant and benign tumors showed perifocal edema and a mass effect to be significantly more common in malignant lesions. Homogeneous enhancement suggested a benign tumor and an inhomogeneous pattern represented malignancy, while the lack of obvious enhancement did not always suggest benignity. Intratumoral calcium deposition was a not uncommon finding in malignant tumors.
Conclusion: In most cases, the exact diagnosis should be made by histological examination but it is important for treatment planning that the appropriate depiction of tumor extension and tissue characterization be made by MR and CT.