Choroid plexus papilloma
The choroid plexus papilloma is a rare benign brain tumor, that of the outer layer ( epithelium ) of the vein plexus ( choroid plexus ) emanates. Choroid plexus are rare tumors that account for only about 0.4 to 0.6% of all brain tumors. The vast majority of children and young people are affected. The choroid plexus papilloma leads to an increase in intracranial pressure with headache, nausea and vomiting. The diagnosis is made by MRI. After surgical removal of the healing view is very low, so the tumor according to the WHO classification of tumors of the central nervous system is classified as grade I.
Distinguished from benign plexus papillomas are the atypical choroid plexus papilloma and the malignant Plexuskarzinom.
Clinical features and diagnosis
Because of its location within the inner fluid spaces of the brain choroid plexus often impede the flow of cerebrospinal fluid, which can lead to an increase in intracranial pressure. Headache, nausea and vomiting are typical but non-specific symptoms. In advanced cases may develop hydrocephalus ( water on the brain ) can occur.
In magnetic resonance imaging to choroid plexus provide quite characteristic as intense homogeneous contrast agent dar. receiving, located in the ventricles of the brain mass with a cauliflower -like shape
Pathology
The histological picture is similar with the formation of papillary structures choroid plexus largely that of the normal. Tumors ( in particular an increased mitotic activity ) have atypical histological features are referred to as atypical choroid plexus papilloma.
Diagnostically helpful is the immunohistochemical detection of expression of cytokeratin and transthyretin. Difficulties in adults can be distinguished from brain metastases prepare. The detection of expression of plexustumor - specific markers may help to substantiate the diagnosis of a Plexuspapilloms.
Pathogenesis
In the vast majority are sporadic cases, ie, cases in which no association with an inherited disease is recognizable. Choroid plexus seldom may occur in the context of syndromes, such as the Aicardi syndrome or the Li -Fraumeni syndrome. Little is known about the pathogenesis ( pathogenesis ) of sporadic choroid plexus mechanisms involved. In particular, there is a viral pathogenesis is no convincing evidence. Although succeeded in Plexuspapillomgewebe the detection of genetic material of the simian virus 40 (SV40 ), which can produce tumors in animal models, but this has only been possible in population groups that had received 1955-1963 contaminated with the SV40 virus vaccine against polio ( for example, in the United States). As the incidence of plexus papillomas in comparison to other countries was not increased in this period, it is the SV40 detection probably an epiphenomenon ( favoring virus replication in patients with latent infection) and no causal link.
Treatment and Prognosis
The tumor can almost always be completely removed surgically. Due to the rarity of tumors of the choroid plexus further treatment in clinical trials will be carried out. Currently, the only clinical trial is the CPT- SIOP - 2000 study, a therapeutic trial conducted under the auspices of the International Society of Paediatric Oncology ( SIOP ) is performed.
After complete surgical removal of the prognosis of plexus papillomas is favorable. Postoperative radiotherapy or chemotherapy in completely resected plexus papillomas is not required ( WHO grade I ) as opposed to atypical plexus papillomas and Plexuskarzinomen therefore usually. Only in individual cases has been described a metastatic spread along CSF or malignancy.
Veterinary Medicine
In dogs make choroid plexus of up to 14 percent of all tumors located in the skull. They rarely occur in other animals, such as goats and cattle.