Pediatric brain stem tumors: radiographic, pathological, and clinical correlations.

A retrospective analysis of the case histories of 21 pediatric patients (ages, 2.5 to 18 years) with a histologically proven diagnosis of brain stem glioma was performed to determine whether patterns of radiographic appearance could be correlated with pathology. Based on the computed tomographic or pneumoencephalographic appearance of the tumor at the time of clinical diagnosis, tumors were divided into four types: central intrinsic (Type I), central exophytic expansion into the 4th ventricle (Type II), eccentric exophytic expansion not involving the 4th ventricle (Type III), and both eccentric and central exophytic expansion (Type IV). Regardless of the radiographic classification, all patients except one, who harbored a well-differentiated astrocytoma in the area of the pons, had an anaplastic astrocytoma (n = 14) or a glioblastoma multiforme (n = 6). There was no appreciable difference in survival between patients with either tumor histology. The presence of a cystic component did not affect survival. High resolution computed tomographic scans, with reconstructed images of the posterior fossa, can predict the presence and location of brain stem tumors and associated cysts and probably the histological nature of the tumor.