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Intraventricular Tumour Dr: ABD ALLAH NAZEER MD Intraventricular neoplasms are rare and arise from periventricular structures such as the walls of the ventricular system, the septum pellucidum and the choroid plexus. Many tumour types arise from, or can bulge into the ventricular system, although there are certain lesions that are relatively restricted to ventricles Neoplasms of the ventricular wall and septum pellucidum ependymoma subependymoma central neurocytoma subependymal giant cell astrocytoma Neoplasms of the choroid plexus choroid plexus papilloma choroid plexus carcinoma Others intraventricular meningioma intraventricular metastasis oligodendroglioma pilocytic astrocytoma glioblastoma multiforme intraventricular CNS lymphoma medulloblastoma primitive neuroectodermal tumour sarcoma intraventricular teratoma Non-neoplastc lesions colloid cysts neurocysticercosis intracranial hydatid cyst intracranial tuberculoma Subependymomas are uncommon, benign (WHO grade I) tumours which are slow growing and non-invasive These tumours were previously also known as subependymal astrocytomas, not to be confused with subependymal giant cell astrocytomas seen with tuberous sclerosis They are also considered by some to be variants of ependymomas, with which they may co-exist Sites: fourth ventricle: 50-60%, lateral ventricles: 30-40%, third ventricle: rare central canal of the spinal cord: rare They are usually small, typically less than 2cm in size CT Isodense to somewhat hypodense intraventricular mass compared to adjacent brain, which does not usually enhance If large, it may have cystc or even calcific (up to half of cases ) components Surrounding vasogenic oedema is usually absent MRI: T1WI iso - hypointense to white matter usually homogenous but may be heterogenous in larger lesions T2 WI: hyper intense to adjacent white and grey matter again, heterogeneity my be seen in larger lesions, with suceptbility related signal drop out due to calcificatons occasionally seen no adjacent parenchymal oedema (as no brain invasion is present) T1 C+ (Gd) usually no enhancement, although at tmes may demonstrate mild enhancement Intra-ventricular lymphoma A colloid cyst of the third ventricle is a benign epithelial lined cyst with characteristic imaging features Although usually asymptomatic, they can present with acute and profound hydrocephalus CT: Typically seen as a well defined, rounded lesion at the roof of the rd ventilcle unilocular typically hyperdense isodense and hypodense cysts are uncommon calcification is uncommon MRI: MR signal characteristics include T1 - typically high T1 signal (short T1) - can be variable T1 C+ (Gd) - only rarely demonstrates thin rim enhancement, but usually this represents enhancement of the adjacent and stretched septal veins T2 - typically low T2/T2* signal (short T2) - can be variable Colloid cysts Colloid cysts Cysticercosis is currently considered the most common parasitic disease of the CNS In about 10% of neurocysticercosis cases, the cysts are found within the cerebral ventricles or in cisterns. The lesions are usually clinically silent until obstruction occurs, secondary to either the location of the cystic lesion or associated ependymitis caused by adjacent granulomatous response The most common symptoms are related to hydrocephalus The onset of symptoms, including headache, vomiting, seizures, can be rather sudden and can result in death A degenerating cyst can cause symptoms of meningitis Intra-cerebral neurocysticercosis Intra-ventricular neurocysticercosis Intra-ventricular neurocysticercosis Hydatid disease is caused by the Echinococcus granulosus of the canine tapeworm The normal cycle is: dog as worm carrier and definitive host and sheep as echinococcus carrier and intermediate host Man is an accidental echinococcus carrier Hydatd cyst within the right lateral ventricle
Ngày đăng: 13/08/2020, 09:15
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