Choroid plexus papilloma, also known as papilloma of the choroid plexus, is a rare benign neuroepithelial intraventricular WHO grade I lesion found in the

choroid plexus The choroid plexus, or plica choroidea, is a plexus of cells that arises from the tela choroidea in each of the ventricles of the brain. Regions of the choroid plexus produce and secrete most of the cerebrospinal fluid (CSF) of the central nerv ...

. It leads to increased

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...

production, thus causing increased

intracranial pressure Intracranial pressure (ICP) is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue. ICP is measured in millimeters of mercury (mmHg) and at rest, is normally 7–15 Millimeter of mercury, mmHg ...

and

hydrocephalus Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain. This typically causes increased intracranial pressure, pressure inside the skull. Older people may have headaches, double vision, poor ...

. Choroid plexus papilloma occurs in the

lateral ventricles The lateral ventricles are the two largest ventricles of the brain and contain cerebrospinal fluid (CSF). Each cerebral hemisphere contains a lateral ventricle, known as the left or right ventricle, respectively. Each lateral ventricle resemble ...

of children and in the

fourth ventricle The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ve ...

of adults. This is unlike most other pediatric tumors and adult tumors, in which the locations of the tumors is reversed. In children, brain tumors are usually found in the

infratentorial In anatomy, the infratentorial region of the brain is the area located below the tentorium cerebelli. The area of the brain above the tentorium cerebelli is the supratentorial region. The infratentorial region contains the cerebellum The cerebe ...

region and in adults, brain tumors are usually found in the

supratentorial In anatomy, the supratentorial region of the brain is the area located above the tentorium cerebelli. The area of the brain below the tentorium cerebelli is the infratentorial region. The supratentorial region contains the cerebrum, while the infra ...

space. The relationship is reversed for choroid plexus papillomas.

Epidemiology

CPPs are rare tumors of neuroectodermal origin. They make up 0.4 to 0.6 percent of all intracranial neoplasms in children and are the third most prevalent congenital brain tumors after teratomas and gliomas. With a median age upon diagnosis of 3.5 years, this lesion is often a disease of infancy. They often reside supratentorial in the lateral ventricles of infants (most commonly in the atrium).Dash C, Moorthy S, Garg K, Singh PK, Kumar A, Gurjar H, Chandra PS, Kale SS. Management of Choroid Plexus Tumors in Infants and Young Children Up to 4 Years of Age: An Institutional Experience. World Neurosurg. 2019 Jan;121:e237-e245. The fourth ventricle in adults is the optimum location.Prasad GL, Mahapatra AK. Case series of choroid plexus papilloma in children at uncommon locations and review of the literature. Surg Neurol Int. 2015;6:151. Adults rarely have it at the cerebellopontine angle.

Etiology

Simian virus (SV) 40 has been linked in studies to the development of choroid plexus tumors (CPTs). The BK and JC viruses have also been linked to the problem.Zhen HN, Zhang X, Bu XY, Zhang ZW, Huang WJ, Zhang P, Liang JW, Wang XL. Expression of the simian virus 40 large tumor antigen (Tag) and formation of Tag-p53 and Tag-pRb complexes in human brain tumors. Cancer. 1999 Nov 15;86(10):2124-32. In people with choroid plexus tumors, complexes formed by the big T antigen and the tumor suppressor proteins p53 and pRb have been shown to develop. However, the available evidence do not suggest a causal involvement. There is currently no additional causal component being investigated. One of the most prevalent mutations in CPTs is the TP53 R248W mutation.

Signs and symptoms

Signs of the tumor resulting from increased

are present in 91% of patients, with

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the Human nose, nose. Vomiting can be the result of ailments like Food-poisoning, foo ...

, homonymous visual field defects and

headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...

being the most common symptoms. Other symptoms are ear ringing and dizziness.

Pathophysiology

Choroid plexus tumors are divided into three categories by the World Health Organization (2016): papillomas (grade I), atypical tumors (grade II), and carcinomas (grade III). Less than two mitotic figures per 10 high power fields are present in CPPs, two to five are present in atypical ones, and more than five are present in carcinomas. The tumors are visible as pink, soft, spherical lumps with erratic projections and considerable vascularity.

Histopathology

The tumor is neuroectodermal in origin and similar in structure to a normal

. They may be created by

epithelial cell Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...

s of the

. Papillary fronds lined by bland columnar epithelium are visible under the microscope. Normal absences include mitotic activity, nuclear pleomorphism, and necrosis. Tumors have positive immunohistochemistry for cytokeratin, vimentin, podoplanin, and S-100.Up to 20% of choroid plexus papilloma patients may test positive for glial fibrillary acidic protein (GFAP). Studies have found that fourth ventricle cancers express more S100 than lateral ventricle tumors, and older patients (over 20 years) express more GFAP and transthyretin than younger patients.Some individuals with choroid plexus papilloma have germline TP53 gene mutations, according to genetic analyses. These cancers rarely exhibit nuclear p53 protein positivity. Aicardi syndrome, hypomelanosis of Ito, and 9p duplication are syndromic correlations of choroid plexus papilloma. Image:Choroid plexus papilloma micrograph.jpg,

Micrograph A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an object. This is opposed to a macrograph or photomacrograph, an image which is also taken on a mic ...

of a choroid plexus papilloma.

H&E stain Hematoxylin and eosin stain ( or haematoxylin and eosin stain or hematoxylin-eosin stain; often abbreviated as H&E stain or HE stain) is one of the principal tissue stains used in histology. It is the most widely used stain in medical diagnos ...

. Image:Plexuspapillom Detail.jpg, Plexuspapillom Detail Image:Plexuspapillom Overview.jpg, Plexuspapillom Overview

Diagnosis

A neurosonogram (NSG) via the anterior fontanelle will show an echogenic lesion inside the ventricles if the fontanelles are not united. This lesion exhibits bidirectional flow throughout the diastole, demonstrating blood flow via disorganized vascular arrangement. Sometimes ultrasound scans are used to diagnose the lesions before birth. An isodense or slightly hyperdense lesion inside the ventricles, as well as the resulting ventriculomegaly, are visible on computer tomography (CT). The intraventricular lobulated masses are well-defined and resemble fronds; they are hypointense on T1WI and hyperintense on T2WI on magnetic resonance imaging (MRI). Active blood flow is indicated by the presence of flow voids. A rich vascularity gives the lesions a brilliant enhancing quality. Recent researches have shown that choroid plexus papilloma and choroid plexus cancer may be distinguished from one another using arterial spin labeling.

Treatment

There is disagreement about the best time to do surgery on tumors that were discovered accidentally.Laarakker AS, Nakhla J, Kobets A, Abbott R. Incidental choroid plexus papilloma in a child: A difficult decision. Surg Neurol Int. 2017;8:86. An option may be an immediate surgical removal, or surgery might be postponed until follow-up imaging reveals radiographic abnormalities or hydrocephalus, or surgery might be a possibility if the patient starts to experience symptoms. Once hydrocephalus occurs, it is simpler to remove the tumor since there is more room around it and the path to the ventricles is shorter. Such a policy has the drawback that patients may experience focused deficiencies as a result of seizures, subarachnoid hemorrhage, or mass impact. In addition, patients often experience cognitive problems as tumor progress. In symptomatic patients, since these tumors are benign, gross total resection (GTR) is the preferred course of therapy. The chance of a cure has nearly reached 100% because to recent improvements in imaging, surgical techniques, and intensive care quality. Significant (12 percent) perioperative mortality occurs in the juvenile population, with catastrophic blood loss accounting for the majority of cases. Preoperative embolization can improve the likelihood of a full tumor resection and reduce this risk. Radiosurgery could be a therapy option. To decrease blood flow and increase tumor resectability, percutaneous stereotactic intratumoral embolization with a sclerosing agent has also been tried. Although it is rarely used, adjuvant chemotherapy can prolong survival and prevent recurrence. Irradiation followed by subtotal resection may be used to treat a developing residual choroid plexus papilloma, making it more likely to success. Malignant tumors and those with leptomeningeal dissemination require adjuvant treatment as well. Bevacizumab is playing a bigger part in disseminated choroid plexus papilloma, according to recent research.

Differential Diagnosis

Choroid plexus papilloma differentials include the following: Meningioma, Chordoid glioma, Rosette-forming glioneuronal tumor, Central nervous system lymphoma Metastasis, Central neurocytoma, Intraventricular tumors such as papillary ependymoma, Subependymoma, Subependymal giant cell tumor, Choroid plexus tumors, Medulloblastoma.

Prognosis

The prognosis of patients has been significantly enhanced by advances in surgical and critical care treatments. Maximum tumor removal is associated with improved progression-free and overall survival. Recurrences are uncommon. Although uncommon, reports of suprasellar metastases and craniospinal seeding have been made.

Complications

Children who have had their intracranial pressure elevated for a long time may come with symptoms such papilledema, optic atrophy, and vision loss that may not improve after surgery. Some may experience postoperative convulsions, bleeding, and cognitive impairments.Additionally, reports of postoperative CSF rhinorrhea have been reported.Lechanoine F, Zemmoura I, Velut S. Treating Cerebrospinal Fluid Rhinorrhea without Dura Repair: A Case Report of Posterior Fossa Choroid Plexus Papilloma and Review of the Literature. World Neurosurg. 2017 Dec;108:990.e1-990.e9.

References

External links

Choroid Plexus Papilloma
MRI, CT, and pathology images from MedPix {{CNS diseases of the nervous system Brain tumor