Neuroimaging clinics of North America
-
There are 2 types of central nervous system lymphoma: primary and secondary. Both have variable imaging features making them diagnostic challenges. ⋯ Moreover, special types of lymphoma, such as lymphomatosis cerebri, intravascular lymphoma, and lymphomatoid granulomatosis, also are found. This article discusses uncommon types of lymphoma and the differential diagnosis for focal, multifocal, meningeal, and infiltrative lymphomas.
-
Metastatic cancer to the central nervous system is primarily deposited by hematogenous spread in various anatomically distinct regions: calvarial, pachymeningeal, leptomeningeal, and brain parenchyma. A patient's overall clinical status and the information needed to make treatment decisions are the primary considerations in initial imaging modality selection. ⋯ Morphologic MR imaging is limited to delineating anatomic deraignment of tissues. Dynamic susceptibility contrast-enhanced perfusion and diffusion-weighted physiology-based MR imaging sequences have been developed that complement morphologic MR imaging by providing additional diagnostic information.
-
In adults, the most common expansile "mass" lesion in the posterior fossa is a subacute stroke, whereas the most common neoplastic lesion in the posterior fossa is cerebellar metastasis (intra-axial) or vestibular schwannoma (extra-axial). Those diseases fall outside the scope of this article, which focuses on primary intra-axial tumors of the posterior fossa in adults. This category of tumors is uncommon and more frequently encountered in children. This article reviews tumors of the cerebellum, brainstem, and fourth ventricle that are seen in adult patients, following categories from the 2007 World Health Organization classification of central nervous system tumors.