Intrinsic brain-stem tumors of childhood: surgical indications.

This report summarizes the first author's experience with radical excision of intrinsic non-exophytic brain-stem gliomas in 34 pediatric patients. On retrospective analysis, these tumors may be classified into three subgroups: focal, diffuse, and cervicomedullary. A focal neoplasm is a circumscribed mass less than 2 cm in diameter and without associated edema. Tumors of a larger size or in which the "focal" neoplasm is associated with a large area of apparent edema are classified as diffuse. Cervicomedullary neoplasms occur at the junction of the medulla and spinal cord and involve both of the structures but do not extend rostrally into the pons. A radical tumor excision was carried out in all patients, and the only mortality and morbidity occurred in children harboring diffuse gliomas. All of the diffuse gliomas were malignant (grade III or IV astrocytomas), whereas three of the four focal astrocytomas and all of the cervicomedullary tumors were grade II astrocytomas. No patient with a diffuse astrocytoma was benefitted by surgery, while two of the focal astrocytomas and all of the cervicomedullary neoplasms either became stable or improved postoperatively. It is concluded that, although surgery may be accomplished within the substance of the brain stem with low morbidity and mortality rates, it is not indicated for malignant astrocytomas as it has no impact on the biology of the neoplasm. Therefore, while primary radical excision is recommended for cervicomedullary neoplasms, which are often benign, the more traditional radiation therapy and/or chemotherapy remain appropriate for tumors above the medulla.