Brain Stem Tumors.

Brain stem tumors are heterogeneous. They range from the diffuse pontine tumors, which are almost invariably fatal despite all known therapies, to lower-grade focal or exophytic tumors that often have a very good prognosis with surgery or observation only. In this article, we review the epidemiology of brain stem tumors and note that diffuse pontine tumors, although rare, are a significant contributor to mortality among pediatric oncology patients. Diagnosis in typical cases is made using a magnetic resonance imaging scan without biopsy. No highly effective standard treatment exists; therefore, inclusion of eligible patients in well-designed clinical research studies is extremely important. If an appropriate trial is not available, conventionally fractionated external beam radiation therapy can provide good short-term palliation to a significant proportion of patients. An important area of preclinical research that may soon be investigated in clinical trials for patients with diffuse pontine tumors is interstitial infusion of therapeutic agents, and the rationale for that approach is described in detail. Lastly, autopsy should be considered for patients who die of diffuse pontine tumors with the goal of obtaining tumor tissue for biological studies that may in the future lead to novel therapies.