Common pediatric brain tumors. Typical computed tomographic appearances

Tumors of the lateral ventricles

Tumors are only rarely found in the lateral ventricles. Although various oncotypes of these tumors differ in growth rate and invasiveness they present the same clinical pattern with the same diagnostic and surgical problems. Thus we can consider them as a group. This series comprises 51 primary tumors arising strictly from the structures of the lateral ventricles, the majority from the trigone, operated on between 1952 and 1988: 20 meningiomas, 19 ependymomas, 9 papillomas of the choroid plexuses, and 3 subependymomas. As most of these tumors were benign, the response to surgical treatment was, as other authors have found, good with permanent cure or long survival in the majority of cases. Advances in neuroradiological techniques have greatly facilitated the work-up and differential diagnosis of these tumors. Of the various surgical approaches, the parieto-occipital is preferred by our department, even for tumors of the dominant hemisphere. Our operative mortality of 10.6% tallies with that of other workers.

Suprasellar germinoma--occult presentation with hypothalamic failure 18 months before diagnosis

Hormonal evidence of widespread hypothalamic failure, including diabetes insipidus, hyperprolactinaemia, growth failure, hypothyroidism, and adrenal failure, was present in a boy of 14 years. Investigation with computerised axial tomography (CT) and metrizamide encephalography failed to identify any anatomical abnormality at the time of presentation. However, 18 months later papilloedema was noted at which time a suprasellar mass and gross dilatation of the ventricular system were readily identified using CT and a germinoma was subsequently diagnosed and treated. In the light of this experience we recommend that when "idiopathic" hypothalamic failure is diagnosed, imaging procedures, including CT or nuclear magnetic resonance examinations, should be repeated on at least one occasion, after an interval of approximately 6 months.

Malignancy criteria in computed tomography of primary supratentorial tumors in infancy and childhood

The CT findings of 11 malignant primary supratentorial tumors in children are compared with those of 38 benign tumors. The malignant tumors were more often laterally placed and surrounded by edema. Irregular tumor shape and high or "mixed" density were more frequent in the malignant group where larger tumor volume was found. The contrast enhancement pattern was also different. Thus, ring enhancement with central lucency was more often seen in the malignant tumors. Seven of the malignant tumors had both irregular shape and edema, while this combination was not present in any of the 38 benign tumors.

Giant cystic craniopharyngiomas

Three cases of giant cystic craniopharyngiomas with large areas of extension beyond the suprasellar area are presented. The magnetic resonance (MR) appearance in one case is described. These giant tumors had large, multilobulated cysts that comprised the bulk of the tumors. In one case, there was an unusual extension of the large tumor cyst into the lateral ventricle. In two cases, the tumors extended to the level of the foramen magnum. On CT, the cyst contents of these two tumors were hyperdense and became hypodense postoperatively. All three tumors harbored calcifications in the form of clumps in the suprasellar region and rim calcifications around the cysts. None of the tumors exhibited contrast enhancement. A literature review of the radiographic features of craniopharyngiomas is discussed.