Pediatric brain stem gliomas: an update.

It has become evident that pediatric brain stem gliomas are a heterogeneous pathology and should be classified according to clinical and radiological criteria. This classification has contributed to better treatment and greatly improved prognosis. Based on a review of the literature, we describe the different types of brain stem astrocytomas reported, which are: cervicomedullary, exophytic, cystic, focal and diffuse. Particular attention is paid to therapeutic modalities. For the first three lesions named the treatment is surgical and oncological therapy should be evaluated only for regrowth of the mass. Focal tumors of the medulla and pons are still treated empirically (surgically and/or with radiotherapy), because a definitive therapeutic protocol has not yet been elaborated; on the other hand it is well established that if the focal mass is in the midbrain this should merely be monitored by means of serial MRI, while radiotherapy should be applied in the event of the tumor's growth. Diffuse gliomas are treated with oncological therapy, and surgery (for biopsy or tumor excision) is not indicated. Five illustrative cases from our department are presented.