Choroid Plexus Papilloma Research Articles

Myc and Loss of p53 Cooperate to Drive Formation of Choroid Plexus Carcinoma.

Choroid plexus carcinoma (CPC) is a rare brain tumor that occurs most commonly in very young children and has a dismal prognosis despite intensive therapy. Improved outcomes for patients with CPC depend on a deeper understanding of the mechanisms underlying the disease. Here we developed transgenic models of CPCs by activating the Myc oncogene and deleting the Trp53 tumor suppressor gene in murine neural stem cells or progenitors. Murine CPC resembled their human counterparts at a histologic level, and like the hypodiploid subset of human CPC, exhibited multiple whole-chromosome losses, particularly of chromosomes 8, 12, and 19. Analysis of murine and human CPC gene expression profiles and copy number changes revealed altered expression of genes involved in cell cycle, DNA damage response, and cilium function. High-throughput drug screening identified small molecule inhibitors that decreased the viability of CPC. These models will be valuable tools for understanding the biology of choroid plexus tumors and for testing novel approaches to therapy. SIGNIFICANCE: This study describes new mouse models of choroid plexus carcinoma and uses them to investigate the biology and therapeutic responsiveness of this highly malignant pediatric brain tumor.

TMOD-05. C-MYC OVEREXPRESSION INDUCES CHOROID PLEXUS PAPILLOMAS THROUGH A T-CELL MEDIATED INFLAMMATORY MECHANISM

Choroid plexus tumours (CPTs) account for up to 20% of brain tumours in children under 2 years of age. They can spread along the neuraxis and can recur after treatment. Little is known about the molecular mechanisms underlying their formation and only few high fidelity mouse models of p53-deficient malignant CPTs are available. We show here that c-Myc overexpression in the choroid plexus epithelium induces T-cell inflammation-dependent choroid plexus papillomas in a mouse model. We demonstrate that c-MYC is expressed in a substantial proportion of human choroid plexus tumours and that this subgroup of tumours is characterised by an inflammatory transcriptome and significant inflammatory infiltrates. Together with the deregulation of the IL36/IL1RL2 axis observed in c-Myc-dependent murine and c-MYC positive human CPTs, our data raise the possibility that benign choroid plexus tumours expressing c-MYC could be amenable to medical therapy with anti-inflammatory drugs rather than surgical therapy.

Perinatal (fetal and neonatal) choroid plexus tumors: a review.

The object of this review is to describe the choroid plexus tumors (CPTs) occurring in the fetus and neonate with regard to clinical presentation, location, pathology, treatment, and outcome. Case histories and clinical outcomes were reviewed from 93 cases of fetal and neonatal tumors obtained from the literature and our own institutional experience from 1980 to 2016. Choroid plexus papilloma (CPP) is the most common tumor followed by choroid plexus carcinoma (CPC) and atypical choroid plexus papilloma (ACPP). Hydrocephalus and macrocephaly are the presenting features for all three tumors. The lateral ventricles are the main site of tumor origin followed by the third and fourth ventricles, respectively. CPTs of the fetus are detected most often near the end of the third trimester of pregnancy by fetal ultrasound. The extent of surgical resection plays an important role in the treatment and outcome. In spite of excellent survival, which is especially true in the case of CPP, surgical resection may carry significant risks in an immature baby. Given the neonatal low blood volume and increased vascularity of the tumors, there is potential risk for hemorrhage. Although advances in neurosurgical techniques have led to a greater degree of complete surgical resections, survival for the perinatal CPC group remains low even with multimodality therapies. Perinatal CPTs have variable overall survivals depending on degree of surgical resection and tumor biology. An increased understanding of the molecular features of these tumors may lead to improved therapies and ultimately survival.

Therapeutic approach to choroid plexus tumors of infants: single center experience

Giriş: Koroid pleksus gebeliğin 6. haftasında nöroepitelial duvardan gelişmeye başlar. Bu hücrelerden köken alan koroid pleksus tümörlerinin geniş spektrumlu histolojik ve biyolojik özellikleri bulunmaktadır. İntrakranial tümörlerin % 0.2-1ini oluştururlar. Hemen her zaman artmış kafa içi basınç bulguları ile birliktedirler. Tanıda kompüterize tomografi ve manyetik rezonans görüntüleme esastır. Tedavi ise gros total rezeksiyondur. Çalışmamızın amacı her iki lateral ventrikülü ve üçüncü ventrikülü dolduran nadir görülen diffüz villöz hiperplazi olgusunu sunmak ve koroid plexus tümölerinde tedavi yaklaşımı ve cerrahi sonuçları tartışmaktır.Gereç ve Yöntem: 2011 ve 2017 yılları arasında 11 hastaya cerrahi uyuladık: 9 olguda koroid plexus papillomu, 1 olguda atipik koroid plexus papillomu ve 1 olguda diffüz villöz hiperplazi mevcuttu. Olguların en küçüğü 2 aylık en büyüğü 12 aylık olup ortalama yaş 8.6 ay idi. Olguların 4 ü kız, 7 si erkekti. Tümör olguların 7 sinde sol, 3 ünde sağ lateral ventrikülde 1 inde her iki lateral ventrikül ve 3 ventrikülde idi. Tüm olgularda tanı ve takip radyolojik inceleme ile gerçekleştirildi.Bulgular: Hastalarımızın tümünde artmış kafa içi basıncına bağlı bulgular vardı ve 3 hastamıza hidrosefali nedeni ile ventriküloperitoneal şant uygulandı. Ortalama takip süremiz 3.6 yıl olup hastalarımızın hepsi yaşamaktadır.Sonuç: Koroid pleksus tümörleri tedavisinde gros total eksizyon esastır.

Choroid plexus tumours on MRI: similarities and distinctions in different grades

BackgroundThe therapeutic planning varies for different grades of choroid plexus tumours (CPTs). The aim of this study was to define the similarities and distinctions among MRIs for different grades of CPTs, providing more guidance for clinical decisions.MethodsWe reviewed the MRI findings in 35 patients with CPT verified by surgical pathology, including 18 choroid plexus papillomas (CPPs, grade I), 11 atypical choroid plexus papillomas (aCPPs, grade II), and 6 choroid plexus carcinomas (CPCs, grade III). Nonparametric testing based on ranks was performed to evaluate the association of pathological grade with MRI findings.ResultsAmong the 35 CPTs, 29 were located in the ventricular system. The tumours were generally slightly hypo- or isointense on T1WI, slightly hyper- or isointense on T2WI, and moderately or strongly enhanced in post-contrast imaging. Twenty cases were accompanied by hydrocephalus. The median tumour longest diameters of CPPs, aCPPs, and CPCs were 28.6, 44.6, and 60.6 mm, respectively. Four cases were purely cystic, 6 were papillary, 10 were lobulated, and 2 were irregular. Three cases had necrosis. The median oedema diameters of CPPs, aCPPs, and CPCs were 0, 0, and 24.1 mm, respectively. The grades of CPTs were statistically associated with tumour longest diameter (rs = 0.68, P < 0.001), internal morphology (χ2 = 10.32, P = 0.016), necrosis (Z = 2.27, P = 0.023), and oedema diameter (rs = 0.72, P < 0.001).ConclusionCPTs typically appeared as intraventricular papillary or lobulated lesions, often accompanied by hydrocephalus. Larger tumour, irregular or fuzzy internal morphology, presentation of necrosis and wide-ranging peritumoural oedema might increase the likelihood of malignancy.

Intracranial Neoplasms in the First Year of Life: Results of a Third Cohort of Patients From a Single Institution.

Brain tumors in the first year of life are rare and their management remains challenging. To report on the contemporary management of brain tumors in infants with reference to previous series from our institution. Retrospective cohort study design. Electronic/paper case note review of all brain tumors diagnosed at our institution in children aged <1 yr since the publication of our previous series. Ninety-eight patients were seen. The most common presentations were with vomiting and macrocrania, at a median age of 184 d. Sixty-two percent of tumors were supratentorial. Ninety-one patients underwent 230 procedures; 7 patients had no surgery. One hundred eighteen operations were directly on brain tumors (biopsy 37, subtotal resection 47, gross total resection 34). Ninety-one cerebrospinal fluid diversions, 9 endoscopic procedures, and 13 preoperative embolizations were performed. Operative mortality was 4.4%. Tumor types in order of frequency were choroid plexus papillomas (CPP, 17), primitive neuroectodermal tumor (12), atypical teratoid/rhabdoid tumor (10), high-grade glioma (9), optic glioma (9), ependymoma (8), low-grade glioma (6), pilocytic astrocytoma (6), choroid plexus carcinoma (5), and teratoma (5), with 11 miscellaneous tumors. Survival was 93% at 1 mo (91/98), 64% at 1 yr (61/95), 44% at 5 yr (32/73), 28% at 10 yr (16/58). No patients with CPP or low-grade glioma died. Five-year survival rates were lowest for anaplastic ependymoma, primitive neuroectodermal tumor, and atypical teratoid/rhabdoid tumor. Seventy-seven percent of children reaching school age were in mainstream schooling. Overall survival from neonatal brain tumors remains similar to previous series; analysis of tumor subtypes reveals improvements for CPP and gliomas. Despite increasing operative intervention, operative mortality continues to decline for this group of challenging patients.

A Case of Choroid Plexus Papilloma with Rare Location Presenting with Impaired Consciousness

A Case of Choroid Plexus Papilloma with Rare Location Presenting with Impaired Consciousness

Management of choroid plexus tumors\u2014an institutional experience

BackgroundChoroid plexus tumors are rare entities. Resection is the mainstay of treatment in grade I and grade II tumors and adjuvant treatment is usually reserved for the less frequent choroid plexus carcinoma (CPC). Outcome is not only related to their histological grade but also dependent on their size, location, and presence of often multifactorial disturbances of cerebrospinal fluid (CSF) circulation.MethodsRetrospective analysis of 36 consecutive patients operated on a choroid plexus tumor at our institution in a mixed pediatric and adult population between 1991 and 2016.ResultsTwenty-one CPP, 11 atypical choroid plexus papillomas (aCPP), and four CPC were encountered in 17 children and 19 adults. Regardless of histological grading, gross-total resection (GTR) could be achieved in 91.7% of patients. Tumor recurrence (25.0%) was significantly associated with histological grading (p = 0.004), subtotal resection (p = 0.002), and intraoperatively evident zones of tumor infiltration (p = 0.001). Adjuvant therapy was performed in 19.4% of patients, mainly diagnosed with CPC. The 5-year overall survival rate was 95.2% for CPP and 100.0% for both aCPP and CPC. Survival was related to the extent of resection (p = 0.001), tumor progression (p = 0.04), and the presence of leptomeningeal metastases (p = 0.002). Even after resection, either ventricular or subdural shunting was required in 25.0% of patients.ConclusionsWe could confirm that GTR is crucial for treatment of choroid plexus tumors. Parenchymal tumor infiltration as detected intraoperatively was associated with the extent of resection and not limited to CPC. CSF disturbances mandating treatment may persist after resection.

Choroid Plexus Papilloma with Dandy Walker Variant: Co-existence or Association- A Case Report

Choroid plexus tumors are rare intracranial tumors which account for 0.4-0.6% of all brain tumors. Choroid plexus tumors represent a spectrum of neoplasms derived from papillary epithelium of normal choroid plexus, including well-differentiated papilloma (WHO grade I), intermediate form as atypical Choroid Plexus Papilloma (WHO grade II) and highly aggressive choroid plexus carcinomas (WHO grade III). Though rare, it is responsible for the communicating hydrocephalus in children due to overproduction of cerebrospinal fluid. Due to advances in molecular biology and better understanding of the tumorigenesis of choroid plexus papilloma, now it is established that several genetic syndromes and central nervous sytem abnormalities are associated with this tumor. Here, we reported a case of a 10 months old child who presented with sudden deterioration of consciousness level and after thorough evaluation, diagnosed as a case of Choroid Plexus Papilloma with Dandy Walker Variant. Till date, this is the first reported case of the association/ co-existence of such two conditions which needs further evaluation.&#x0D; Bangladesh Med J. 2017 May; 46 (2): 61-65

Maintaining a methods database to optimize solid tumor tissue culture: Review of a 15-year database from a single institution

Chromosome analysis of solid tumors provides valuable information for diagnosis and patient management, yet successfully culturing solid tumors can be challenging. The Children's Mercy (CM) Cytogenetics laboratory has compiled a database of 1371 non-lymphoma solid tumors cultured since 2002. Analysis of the tumor culture data found a culture success rate of 91.6%. Abnormal karyotypes were identified in 47.0% of these tumors. A quality improvement project reviewed the database for methods, cell culture success, yield of clonally abnormal karyotypes, culture failure, tumor diagnostic category, and other. This review revealed processes that could be optimized with minor changes to methods in a subset of tumors. Three tumor/method pair examples are provided including adrenal cortical carcinomas (ACCs), choroid plexus tumors (CPTs), and neuroblastoma. The successful culture of tumors as defined by capture of clonally abnormal cells is dependent upon several factors including culture medium, monolayer versus suspension culture, length of time in culture, method of disaggregation and other. The database serves as a quality assurance tool that enables continuous improvement in culture success rate and abnormal yield. It is also an educational resource for laboratory technologists, residents and fellows. Using the database to track methods and results ensures consistency in routine tumor processing, facilitates oversight to optimize methods for quality, and improves results for patient care.

Rare Presenting Chronic Choroid Plexus Papilloma Case with Impaired Consciousness

Rare Presenting Chronic Choroid Plexus Papilloma Case with Impaired Consciousness

Reliability of Imaging-Based Diagnosis of Lateral Ventricular Masses in Children

We studied the accuracy of the radiologic diagnosis of lateral ventricular masses in children (<20 years of age). In this retrospective study, data were collected from children with lateral ventricular masses managed in our unit between 2001 and 2016. There were 43 patients (26 boys and 17 girls; mean age, 12.1 years; range, 8 months to 20 years). Magnetic resonance imaging was available for 36 patients, whereas in 7 patients only a contrast-enhanced computed tomography scan was available. The images were read independently by 3 radiologists, who were blinded to the pathology. Two differential diagnoses were offered for each patient. The agreement between the 3 radiologists was calculated using the Fleiss κ statistic. The common pathologic diagnoses were subependymal giant cell astrocytoma (SEGA) (20.9%), low-grade astrocytoma (16.3%), high-grade astrocytoma (9.3%), choroid plexus papilloma (9.3%), and meningioma (9.3%). The sensitivity, specificity, and accuracy of the radiologic diagnoses were 62%, 96.7%, and 94.2%, respectively. Low-grade tumors such as low-grade gliomas, SEGAs, choroid plexus papillomas, and meningiomas were diagnosed with a high level of accuracy. High-grade gliomas, choroid plexus carcinomas, and other malignant neoplasms were difficult to diagnose on imaging. Cavernous angiomas were also difficult to diagnose. There was only fair agreement between the 3 radiologists (Fleiss κ= 0.24). The pathologic spectrum of lateral ventricular tumors in children is wide, and identifying the pathology on imaging is difficult for malignant tumors. Benign tumors such as SEGAs, low-grade astrocytomas, and choroid plexus papillomas are relatively easier to diagnose. There is significant interobserver variability in the radiologic diagnosis of these tumors.

Choroid plexus papilloma: case report

ABSTRACT Choroid plexus papillomas (CPP) are a rare oncological condition. They affect mostly the pediatric population, and the diagnosis is associated with clinical findings, imaging and anatomopathological methods. We report the case of a 49-year-old woman who underwent neurosurgical evaluation for chronic headache and emotional stress. CPP is a rare central nervous system tumor in the adult population. We present, therefore, a case in an adult female, whose diagnosis was confirmed by histopathology methods. Surgical treatment is the gold standard, showing full resolution in almost all cases.

Histomorphological spectrum of paediatric CNS tumours: An experience at tertiary care centre in central India

Tumours of central nervous system occur relatively frequently in early years of life. They are the most common malignancy of childhood after leukaemia in overall cancer incidence. Paediatric brain tumours has histomorphological diversified spectrum & differ significantly from their adult counterpart. Present retrospective observational study was carried out to analyse the histomorphological spectrum of Paediatric CNS tumours at tertiary care centre from central India. This study is an attempt to map the rising trend of paediatric brain tumours in central India. This rise may be due to expansion of available neurosurgical services along with advanced imaging modalities in this part of India. Medulloblastoma, Pilocytic astrocytoma, Ependymoma, Craniopharyngioma & Choroid plexus papilloma were among the top five diagnosis in present study.

Choroid plexus tumor necrosis factor receptor 1: A new neuroinflammatory piece of the complex Alzheimer's disease puzzle.

Due to the aging of the population and despite the enormous scientific effort, Alzheimer’s disease remains one of the biggest medical and pharmaceutical challenges in current medicine. Novel insights highlight the importance of neuroinflammation as an undeniable player in the onset and progression of Alzheimer’s disease. Tumor necrosis factor is a master inflammatory cytokine that signals via tumor necrosis factor receptor 1 and tumor necrosis factor receptor 2, but that also regulates several brain functions in health and disease. However, clinical trials investigating drugs that interfere with the tumor necrosis factor pathway in Alzheimer’s disease led to inconclusive results, partially because not only the pro-inflammatory tumor necrosis factor/tumor necrosis factor receptor 1, but also the beneficial tumor necrosis factor/tumor necrosis factor receptor 2 signaling was antagonized in these trials. We recently found that tumor necrosis factor is the main upregulated cytokine in the choroid plexus of Alzheimer’s disease patients, signaling via tumor necrosis factor receptor 1. In agreement with this, choroidal tumor necrosis factor/tumor necrosis factor receptor 1 signaling was also upregulated in different Alzheimer’s disease mouse models. Interestingly, both genetic and nanobody-based pharmacological blockage of tumor necrosis factor receptor 1 signaling was accompanied by favorable effects on Alzheimer’s disease-associated inflammation, choroidal morphology and cognitive functioning. Here, we briefly summarize the detrimental effects that can be mediated by tumor necrosis factor/tumor necrosis factor receptor 1 signaling in (early) Alzheimer’s disease, and the consequences this might have on the disease progression. As the main hypothesis in Alzheimer’s disease clinical trials is still based on the amyloid beta-cascade, the importance of Alzheimer’s disease-associated neuroinflammation urge the development of novel therapeutic strategies that might be effective in the early stages of Alzheimer’s disease and prevent the irreversible neurodegeneration and resulting memory decline.

Clinical Features and Prognostic Risk Factors of Choroid Plexus Tumors in Children.

Background:Decision-making concerning the treatment of choroid plexus tumor (CPT) in pediatric patients remains a topic of considerable debate. The aim of this work was to describe clinical features and prognostic risk factors of CPT in the pediatric population and to provide theoretical opinions regarding clinical decisions for CPT.Methods:The data of 96 patients with CPT and younger than 14 years were retrospectively analyzed. Clinical characteristics such as pathological type of CPTs, rate and severity of hydrocephalus, treatment and outcome, and recurrence were investigated. For categorical variables, the Pearson's Chi-square test was performed. The Mann–Whitney U-test was used for comparisons between nonnormally distributed parameters. Log-rank test was used for progression-free survival (PFS).Results:The study included 70 choroid plexus papilloma (CPP) cases, 17 atypical choroid plexus papilloma (aCPP) cases, and 9 choroid plexus carcinoma (CPC) cases. Compared with patients with CPP or aCPP, patients with CPC had a shorter disease course (median: CPP, 4 months; aCPP, 2 months; CPC, 1 month; H: 23.5, P < 0.001), higher rate of acute hydrocephalus (CPP, 27.1%; aCPP, 52.9%; CPC, 77.8%; χ2 = 10.9, P < 0.05), and lower incidence of cure rate (CPP, 85.7%; aCPP, 70.5%; CPC, 33.3%; χ2 = 13.5, P < 0.05). The severity of hydrocephalus with tumor in the lateral or third ventricle was significantly higher than that with tumors in the fourth ventricle (severe hydrocephalus: lateral ventricle, 51.7%; third ventricle, 47.0%; fourth ventricle, 11.1%; χ2 = 26.0, P < 0.001). Patients with gross total surgical resection had no better PFS than those with partial resection because of the use of adjuvant therapy in the latter (χ2 = 4.0, P > 0.05). Patients with CPC experienced shorter time for recurrence than those with CPP or aCPP (χ2 = 40.1, P < 0.0001).Conclusions:Our results indicated that CPP in the fourth ventricle could trigger serious clinical symptoms at an early stage, requiring early intervention. Adjuvant treatment might be necessary for patients with partially resected CPP, aCPP, and CPC to achieve a favorable outcome.

Microsurgical Resection of Cerebellopontine Angle Choroid Plexus Papilloma by Far-Lateral Approach. Case Report

Introduction: Choroid plexus tumors (CPTs) are rare papillary neoplasms derived from choroid plexus epithelium. They account for only approximately 0.4%-0.6% of all intracranial tumors, but 10%-20% of brain tumors occurring throughout the first year of life. Objective: The present study describes the case of an adult man presenting a cerebellopontine angle choroid plexus papilloma (CPP) microsurgically treated through suboccipital far-lateral approach. Case report: A 67-years-old-man was admitted presenting progressive headaches and left lower limb weakness. Magnetic resonance images showed a large tumor on the left cerebellopontine angle with heterogeneous contrast enhancement. Total surgical resection was achieved through a right suboccipital far-lateral craniotomy on lateral position with neurophysiological monitoring of lower cranial nerves. No alterations on cranial nerves function was observed during tumor resection. The patient presented an uneventful recovery and was discharged home on the fifth post-operative day. On the six months follow-up, he was asymptomatic. Anatomopathological analysis confirmed the diagnosis of CPP, WHO grade I. Conclusion: Cerebellopontine angle’s cpp is an extremely rare neoplasm that challenges a neurosurgeon ability to deal with tumor in close relation to lower cranial nerves. Appropriate neurosurgical route, surgeons experience and adequate anatomical knowledge of important neural and vascular structures are fundamental to safely remove CPP of the posterior fossa. Suboccipital far-lateral craniotomy gives enough view with minimal retraction to manage the tumor.

Virulence factor-dependent basolateral invasion of choroid plexus epithelial cells by pathogenic Escherichia coli in vitro.

Escherichia coli is the most common Gram-negative causative agent of neonatal meningitis and E. coli meningitis is associated with high morbidity and mortality. Previous research has been carried out with regard to the blood-brain barrier and thereby unveiled an assortment of virulence factors involved in E. coli meningitis. Little, however, is known about the role of the blood-cerebrospinal fluid (CSF) barrier (BCSFB), in spite of several studies suggesting that the choroid plexus (CP) is a possible entry point for E. coli into the CSF spaces. Here, we used a human CP papilloma (HIBCPP) cell line that was previously established as valid model for the study of the BCSFB. We show that E. coli invades HIBCPP cells in a polar fashion preferentially from the physiologically relevant basolateral side. Moreover, we demonstrate that deletion of outer membrane protein A, ibeA or neuDB genes results in decreased cell infection, while absence of fimH enhances invasion, although causing reduced adhesion to the apical side of HIBCPP cells. Our findings suggest that the BCSFB might constitute an entry point for E. coli into the central nervous system, and HIBCPP cells are a valuable tool for investigating E. coli entry of the BCSFB.

Endoscopic Resection of an Intraventricular Tumor With Second Window Indocyanine Green: 2-Dimensional Operative Video.

A 26-year-old woman presented to our clinic with years of headaches and mental clouding. She had a nonfocal neurological examination including benign ophthalmological examination. Head computed tomography and brain magnetic resonance imaging (MRI) demonstrated asymmetry of the lateral ventricles due to a lesion arising from the foramen of Monro. At the top of our differential diagnosis were choroid plexus tumor and colloid cyst. We offered the patient treatment via an endoscopic approach. Here, we demonstrate the feasibility of using tumor-localizing dyes such as indocyanine green (ICG) in conjunction with endoscopes equipped with lasers to localize and treat intraventricular lesions. While ICG is FDA approved, the technique presented here is investigational and the dye is being used off-label. The laser-equipped endoscope is also being used off-label. To treat the ventricular asymmetry, we performed an endoscopic septostomy between the frontal horns of the lateral ventricles. For our tumor-localizing dye technique, we injected the patient with ICG 24 hours before the planned surgery. We were able to clearly visualize the lesion at the foramen of Monro as it was intensely fluorescent. The dye also appeared to localize to the presumably normal choroid plexus. We resected the lesion endoscopically and permanent pathology revealed that the lesion was a choroid plexus papilloma. The postoperative MRI showed improvement in her ventricular asymmetry and complete resection of the enhancing lesion at the foramen of Monro. The patient recovered well and was uneventfully discharged. She was seen in follow-up and has had improvement in her headaches.Consent for surgery was obtained from the patient. Consent for publication of the operative video was also obtained from the patient.

Radiation therapy for intracranial tumours in cats with neurological signs.

The aim of this study was to evaluate the outcome of cats with intracranial tumours presenting with neurological signs treated with radiation therapy. This study comprised a retrospective multicentre case series. Medical records of a total of 22 cats with intracranial space-occupying lesions, presenting with neurological signs and/or epileptic seizures and treated with external beam radiation therapy, were reviewed. In the treated cats, patient-, tumour- and treatment-related variables were investigated, including age, sex, tumour location, tumour volume, total radiation dose, equivalent dose in 2 Gy fractions (EQD2), corticosteroid dose, overall treatment time and institution for influence on local tumour control and survival. Based on advanced imaging characteristics, the 22 treated cats presented with meningioma (n = 11), pituitary tumour (n = 8), choroid plexus tumour (n = 2) or glioma (n = 1). Allocated to the neuraxis, 11 lesions were extra-axial, three were intra-axial and eight were located in the pituitary region. At diagnosis, 21 cats exhibited altered neurological status. One cat presented with epileptic seizures and another cat had both seizures and altered neurological status. The mean total physical dose of radiation was 41.63 Gy (± 4.33), range 24-45 Gy. In all but one cat (95.5%), neurological signs improved after radiation therapy. The median progression-free survival was 510 days (95% confidence interval [CI]: 51-969). The proportion free of progression at 1 year was 55.7% (95% CI: 33-78). Fourteen cats died (only in five cases was death related to the intracranial tumour) and eight cats were still alive or lost to follow-up. The median overall survival time was 515 days (95% CI: 66-964). None of the tested variables influenced outcome. Radiation therapy seems to represent a viable treatment option in cats with intracranial tumours, relieving neurological signs and improving local tumour control. Radiation therapy may be considered for cats with tumours in complicated/inoperable localisations or for cases with a high peri- and postoperative risk.