Nonglial tumors of the brainstem

Nonglial tumors of the brainstem constitute a histologically heterogeneous group of lesions with quite a different behavior and aggressiveness. Therefore, the diverse therapeutic options depend on a correct and prompt diagnosis. We can limit their differential diagnosis by using clinical and demographic data and imaging findings, which in most cases will be a translation of their histologic characteristics. The main clinical, neuroimaging, and pathologic features of these lesions are described according to the last updated classification of the World Health Organization for central nervous system tumors. We provide some useful clues, based on the direct correlation of the imaging appearance with its gross pathologic and histologic appearance, for a comprehensive diagnostic approach. Embryonic tumors (medulloblastoma and primitive neuroectodermal tumor), cavernoma, lymphoma, hemangioblastoma, and ganglionic and mixed tumors as long as lesions affecting the central nervous system by external compression (arising from the skull, cerebrospinal fluid spaces, or extraaxial nervous and vascular elements) are included. All cases presented belong to the archive data of our hospital.