KEY FACTS Terminology Secondary CNS involvement in patients with systemic lymphoma (SCNSL) Imaging Secondary CNS lymphoma: Skull, dura, leptomeninges > > parenchymal mass Best diagnostic clue: Diffusely enhancing dural mass ± bone involvement May see leptomeningeal enhancement or nonsupression of…
KEY FACTS Terminology Brain metastases in locations other than skull/meninges or parenchyma Imaging General features > 95% of brain metastases parenchymal Only 1-2% in ventricles, pituitary gland, etc. Sites generally very vascular Extraventricular metastases more diffuse, infiltrative than parenchymal metastases…
KEY FACTS Terminology Secondary brain tumors (metastases) arise from Tumors outside CNS spreading to CNS (usually via hematogenous dissemination) Primary CNS neoplasms spreading from 1 site to another (usually geographic extension, e.g., along WM tracts) Imaging General features Round enhancing…
KEY FACTS Terminology Acute or chronic myeloid or lymphoid white blood cell neoplasia with spinal involvement as component of systemic disease Imaging Radiographs/CT Diffuse osteopenia with multiple vertebral fractures ± lytic spine lesions Variable enhancing isodense soft tissue mass with…
KEY FACTS Terminology Rare malignancy characterized by intravascular proliferation of lymphoid cells with predilection for CNS and skin Imaging T2/FLAIR multifocal hyperintensities in deep white matter, cortex, and basal ganglia May mimic infarct Diffusion restriction common GRE/SWI: Multifocal hemorrhage often…
KEY FACTS Terminology Malignant primary CNS neoplasm primarily composed of B lymphocytes (PCNSL) Imaging Best diagnostic clue: Enhancing lesion(s) within basal ganglia &/or periventricular white matter 60-80% supratentorial Often involve, cross corpus callosum Frequently contact, extend along ependymal surfaces Classically…
KEY FACTS Terminology Hemangioblastoma (HGBL): Highly vascular tumor of adults most commonly found in posterior fossa (PF), spinal cord 25-40% of HGBLs in von Hippel-Lindau disease (VHL) Imaging Best diagnostic clue: Adult with cerebellar mass with cyst and enhancing mural…
KEY FACTS Terminology Medulloblastoma (MB) Malignant, invasive, highly cellular embryonal tumor 4 distinct MB molecular subgroups Wingless (WNT) Sonic hedgehog (SHH) Group 3 Group 4 Imaging MB subgroups arise in different locations Midline (4th ventricle) – Predominately (but not exclusively)…
KEY FACTS Terminology Intracranial germ cell tumor (iGCT) iGCTs are intracranial homologue of gonadal germinomas (ovarian dysgerminoma, testicular seminoma) Imaging Most common: In/near midline (80-90%) Pineal region ~ 50-65% Suprasellar ~ 25-35% Less common: Basal ganglia/thalami ~ 5-10% 20% multiple…
KEY FACTS Terminology Primary parenchymal neoplasm of pineal gland Intermediate in malignancy between pineoblastoma and pineocytoma Imaging General features Aggressive-looking pineal mass in adult Extension into adjacent structures (ventricles, thalami) is common Lobulated, moderately vascular Size varies from small (<…