Management of choroid plexus tumors-an institutional experience

Developing a nomogram based on SEER database for predicting prognosis in choroid plexus tumors

Choroid plexus tumors (CPT) are rare and highly vascularized neoplasms that have three histologically confirmed diagnoses, including choroid plexus papilloma, atypical choroid plexus papilloma, and choroid plexus carcinoma (CPC). This study aimed to determine the epidemiology and survival of patients with CPTs and develop a nomogram to quantify the prognosis of the patients with CPT. Data of 808 patients who were diagnosed as CPT between 2000 and 2020 was obtained from the surveillance, epidemiology, and end results database. Descriptive analysis was used to assess the distribution and tumor-related characteristics of the patients with CPT. Independent prognostic factors for patients with CPT were identified by univariate and multivariate Cox regression analysis. The nomogram was established and evaluated by receiver operating characteristic curve, and decision curve analysis (DCA), calibration curves. The independent prognostic factors for patients with CPT are age, tumor size, surgery, chemotherapy, tumor number, pathologies, and race. For the prognostic nomogram, the area under the curve (AUC) of 60-, 120-, and 180-months were 0.855, 0.869 and 0.857 in the training set and 0.836, 0.864 and 0.922 in the test set. The DCA and calibration curve indicated the good performance of the nomogram. Patients with CPTs can be diagnosed at any age. Among the three histopathological tumors, patients with CPC had the worst prognosis. The nomogram was established to predict the prognosis of patients with CPT, which had satisfactory accuracy, and clinical utility may benefit for clinical decision-making.

A rare trifocal presentation of a choroid plexus papilloma: Case report and review of the literature

Introduction

CPP's present as slow-growing intraventricular neoplasms arising from epithelium of choroid plexus. They account for approximately 0.5-4% of intracranial neoplasms in adults and children, respectively. A trifocal presentation is exceedingly rare.

Research question

We describe the case of a trifocal presentation of a CPP and explored the importance of genetic analyses.

Material and methods

We present the case of an 18-year old adolescent who was treated for a fourth ventricular and suprasellar neoplasm. Brain MRI revealed an intraventricular lesion in the fourth ventricle, as well as a suprasellar lesion and a lesion located in the left internal auditory meatus. An adult-subtype CPP (WHO grade 1) was confirmed by means of histological and genetic analyses in the first two regions.

Results

Optimal treatment strategy remains controversial, although it is accepted that surgical resection alone remains the gold standard, whereas chemoradiotherapy is reserved for specific cases. There are only a few articles reporting on a multifocal presentation or the coexistence of synchronous histologically different primary brain neoplasms. Reports on genetic examination are scarce.

Discussion and conclusion

CPP's should be included in the differential diagnosis of posterior fossa tumors, both in children and adults. Genetic analyses (TP53/TERT mutations) should be considered, since they entail important diagnostic, prognostic and therapeutic implications. When a TERT mutation is present, adjuvant radiotherapy should be used with caution, since it plays a role in tumorigenesis, even when GTR could not be achieved. There is an association between TERT methylation status and malignant transformation, indicating that these patients should be followed more closely.

Clinical rarity: simultaneous choroid plexus papilloma and extraventricular neurocytoma presenting as intraventricular hemorrhage in an adolescent

We present a patient with an intraventricular hemorrhage. Imaging identified a left atrial intraventricular mass and a vague adjacent second periventricular cystic lesion. A guided trans-sulcal approach via a left parietal craniotomy resulted in a gross total resection of both lesions. These represented two distinct lesions, the periventricular cystic lesion was an extraventricular neurocytoma (EVN) and a World Health Organization grade 1 choroid plexus papilloma (CPP). The neurocytoma required methylation studies for confirmatory diagnosis. The patient had an uneventful recovery with a normal neurological exam at 12-weeks. This documents the occurrence of two distinct central nervous system tumors, a CPP and an EVN presenting with an intraventricular hemorrhage.

Posterior fossa choroidplexus papilloma in the pediatric population: case series and literature review

Choroid plexus papillomas (CPPs) are rare benign neoplasms which are particularly uncommon in the posterior fossa in children. We herein present a case series of five patients treated at a tertiary care hospital. A comprehensive literature review was also carried out. The patients treated at the tertiary care hospital were aged between 4 and 16 years. Gross total resection (GTR) was initially achieved in two patients. All patients showed clinical improvement. Moreover, 27 articles published between 1975 and 2021 were selected for the literature review, totaling 46 patients; with the 5 patients previously described, the total sample was composed of 51 cases, With a mean age was 8.2 years. The lesions were located either in the fourth ventricle (65.3%) or the cerebellopontine angle (34.7%). Hydrocephalus was present preoperatively in 66.7% of the patients, and a permanent shunt was required in 31.6% of the cases. The GTR procedure was feasible in 64.5%, and 93.8% showed clinical improvement. For CPPs, GTR is the gold standard treatment and should be attempted whenever feasible, especially because the role of the adjuvant treatment remains controversial. Neuromonitoring is a valuable tool to achieve maximal safe resection. Hydrocephalus is common and must be recognized and promptly treated. Most patients will need a permanent shunt. Though there is still controversy on its efficacy, endoscopic third ventriculostomy is a safe procedure, and was the authors' first choice to treat hydrocephalus.

Choroid plexus tumors: A spectrum from benign to malignant

Choroid plexus tumors (CPT) are believed to originate from outgrowths of the choroid plexus. Despite their broad spectrum of symptoms, invasive nature, and prognosis, most CPTs typically exhibit similar presentations due to their relationship with the cerebral ventricles, as well as the mechanical obstruction and mass effect associated with their growth. In addition, these tumors mainly affect the pediatric population, further complicating the differentiation between benign and malignant subtypes. The World Health Organization classifies CPTs into three grades, namely, grades I, II, or III, based on their mitotic activity, which determine the benign or malignant nature of the tumors. CPTs classified by the World Health Organization (WHO) include choroid plexus papillomas (CPP), atypical CPPs (aCPP), and malignant choroid plexus carcinomas (CPC). Choroid plexus adenomas represent an additional category of benign CPTs not officially classified by the WHO. Despite the variations in histology, immunohistochemistry, imaging, treatment, and prognosis, CPTs cannot be reliably distinguished based solely on clinical presentation. Therefore, in this review, we aim to provide a comprehensive overview of each tumor subtype, along with the current management approach and emerging treatments.

Preclinical validation of a novel therapeutic strategy for choroid plexus carcinoma

Choroid plexus carcinoma (CPC) is a rare infantile brain tumor with an aggressive clinical course that often leaves children with debilitating side effects due to aggressive and toxic chemotherapies. Development of novel therapeutical strategies for this disease have been extremely limited owing to the rarity of the disease and the paucity of biologically relevant substrates. We conducted the first high-throughput screen (HTS) on a human patient-derived CPC cell line (Children Cancer Hospital Egypt, CCHE-45) and identified 427 top hits highlighting key molecular targets in CPC. Furthermore, a combination screen with a wide variety of targets revealed multiple synergistic combinations that may pave the way for novel therapeutical strategies against CPC. Based on in vitro efficiency, central nervous system (CNS) penetrance ability and feasible translational potential, two combinations using a DNA alkylating or topoisomerase inhibitors in combination with an ataxia telangiectasia mutated and rad3 (ATR) inhibitor (topotecan/elimusertib and melphalan/elimusertib respectively) were validated in vitro and in vivo. Pharmacokinetic assays established increased brain penetrance with intra-arterial (IA) delivery over intra-venous (IV) delivery and demonstrated a higher CNS penetrance for the combination melphalan/elimusertib. The mechanisms of synergistic activity for melphalan/elimusertib were assessed through transcriptome analyses and showed dysregulation of key oncogenic pathways (e.g. MYC, mammalian target of rapamycin mTOR, p53) and activation of critical biological processes (e.g. DNA repair, apoptosis, hypoxia, interferon gamma). Importantly, IA administration of melphalan combined with elimusertib led to a significant increase in survival in a CPC genetic mouse model. In conclusion, this study is, to the best of our knowledge, the first that identifies multiple promising combinatorial therapeutics for CPC and emphasizes the potential of IA delivery for the treatment of CPC.

Durability of an endoscopic management strategy for recurrent choroid plexus carcinoma with a comprehensive molecular characterization: illustrative case

OBJECTIVE

Choroid plexus carcinoma (CPC) is a rare, primarily intraventricular neoplasm. Extent of resection correlates with improved outcomes but is limited due to tumor vascularity and size. Evidence on optimal surgical management and molecular drivers of recurrence remains limited. Here the authors characterize a case of multiply recurrent CPC treated with sequential endoscopic removals over 10 years and highlight its genomic properties.

OBSERVATIONS

Five years after standard treatment, a 16-year-old female presented with a distant intraventricular recurrence of CPC. Whole exome sequencing revealed NF1, PER1, and SLC12A2 mutations, FGFR3 gain, and no TP53 alterations. Repeat sequencing on recurrences 4 and 5 years later showed persistent NF1 and FGFR3 alterations. Methylation profiling was consistent with plexus tumor, subclass pediatric B. Short-term magnetic resonance imaging detected four total isolated recurrences, all treated with complete endoscopic resections at 5, 6.5, 9, and 10 years after initial diagnosis. Mean hospital stay for all recurrences was 1 day with no complications.

LESSONS

The authors describe a patient with four isolated recurrences of CPC over a decade, each treated with complete endoscopic removal, and identify unique molecular alterations that persisted without TP53 alterations. These outcomes support frequent neuroimaging to facilitate endoscopic surgical removal following early detection of CPC recurrence.

Intracranial Subdural Fluid Accumulation Associated with a Choroid Plexus Carcinoma in a Dog

Choroid plexus tumors are commonly described as intraventricular mass lesions and account for 7-10% of intracranial, primary tumors in dogs. A 3-year-old Shetland sheepdog was presented with a history of slowly progressive lethargy, vision impairment and cognitive deficits. On magnetic resonance imaging, a subdural fluid accumulation (SFA) overlying and compressing the left parietotemporal lobe as well as multifocal changes consisting of cyst-like lesions, supposed intra-axial brain lesions and mild, multifocal meningeal thickening and generalized contrast enhancement were identified. Cerebrospinal fluid (CSF) analysis showed a mononuclear pleocytosis with negative results for infectious agents. The dog was treated with prednisolone followed by burr hole craniotomy with puncture of the SFA, which macroscopically appeared to be CSF-like fluid. After initial improvement, the dog deteriorated despite continuation of prednisolone and cytarabine therapy and was euthanized four weeks after surgery. Histopathology was consistent with a disseminated, neuroinvasive choroid plexus carcinoma (CPC) that involved the entire neuroaxis including the meninges of the brain and spinal cord. Immunohistochemical examination showed a strong Kir7.1 and a heterogenous cytokeratin-immunoreactivity in neoplastic cells. In conclusion, a CPC should be considered as a possible cause of a SFA even in the absence of an intraventricular mass lesion.

Cystic dissemination of choroid plexus papilloma: illustrative cases

BACKGROUND

Choroid plexus papillomas are benign tumors of the choroid plexus. Although typically focal, they can metastasize. Rarely, patients may present with numerous cystic lesions throughout the craniospinal axis.

OBSERVATIONS

The authors present three cases of pathologically confirmed fourth ventricular World Health Organization (WHO) grade 1 choroid plexus papillomas presenting with numerous cystic lesions throughout the craniospinal axis. Two cases were treated with only resection of the fourth ventricular mass; one was treated with a partial cyst fenestration. During follow-up, there was only mild interval growth of the cystic lesions over time, and all patients remained asymptomatic from their cystic lesions. The authors summarize five additional cases of cystic dissemination in the published literature and discuss hypotheses for the pathophysiology of this rare presentation.

LESSONS

Choroid plexus papillomas may present with numerous, widely disseminated cystic lesions within the craniospinal axis. Thus, the authors recommend preoperative and routine imaging of the entire neuroaxis in patients with choroid plexus tumors, regardless of WHO grade. Although the role of adjuvant therapy and cyst fenestration in the treatment of these lesions remains unclear, watchful waiting may be indicated, especially in asymptomatic patients, because the lesions often demonstrate slow, if any, growth over time.

Final results of the Choroid Plexus Tumor study CPT-SIOP-2000

Introduction

Standards for chemotherapy against choroid plexus tumors (CPT) have not yet been established.

Methods

CPT-SIOP-2000 (NCT00500890) was an international registry for all CPT nesting a chemotherapy randomization for high-risk CPT with Carboplatin/Etoposide/Vincristine (CarbEV) versus Cyclophosphamide/Etoposide/Vincristine (CycEV). Patients older than three years were recommended to receive irradiation: focal fields for non-metastatic CPC, incompletely resected atypical choroid plexus papilloma (APP) or metastatic choroid plexus papilloma (CPP); craniospinal fields for metastatic CPC/APP and non-responsive CPC. High risk was defined as choroid plexus carcinoma (CPC), incompletely resected APP, and all metastatic CPT. From 2000 until 2010, 158 CPT patients from 23 countries were enrolled.

Results

For randomized CPC, the 5/10 year progression free survival (PFS) of patients on CarbEV (n = 20) were 62%/47%, respectively, compared to 27%/18%, on CycEV (n = 15), (intention-to-treat, HR 2.6, p = 0.032). Within the registry, histological grading was the most influential prognostic factor: for CPP (n = 55) the 5/10 year overall survival (OS) and the event free survival (EFS) probabilities were 100%/97% and 92%/92%, respectively; for APP (n = 49) 96%/96% and 76%/76%, respectively; and for CPC (n = 54) 65%/51% and 41%/39%, respectively. Without irradiation, 12 out of 33 patients with CPC younger than three years were alive for a median of 8.52 years. Extent of surgery and metastases were not independent prognosticators.

Conclusions

Chemotherapy for Choroid Plexus Carcinoma is feasible and effective. CarbEV is superior to CycEV. A subset of CPC can be cured without irradiation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-021-03942-0.

Avoidance or adaptation of radiotherapy in patients with cancer with Li-Fraumeni and heritable TP53-related cancer syndromes

The management of patients with cancer and Li-Fraumeni or heritable TP53-related cancer syndromes is complex because of their increased risk of developing second malignant neoplasms after genotoxic stresses such as systemic treatments or radiotherapy (radiosusceptibility). Clinical decision making also integrates the risks of normal tissue toxicity and sequelae (radiosensitivity) and tumour response to radiotherapy (radioresistance and radiocurability). Radiotherapy should be avoided in patients with cancer and Li-Fraumeni or heritable TP53 cancer-related syndromes, but overall prognosis might be poor without radiotherapy: radioresistance in these patients seems similar to or worse than that of the general population. Radiosensitivity in germline TP53 variant carriers seems similar to that in the general population. The risk of second malignant neoplasms according to germline TP53 variant and the patient's overall oncological prognosis should be assessed during specialised multidisciplinary staff meetings. Radiotherapy should be avoided whenever other similarly curative treatment options are available. In other cases, it should be adapted to minimise the risk of second malignant neoplasms in patients who still require radiotherapy despite its genotoxicity, in view of its potential benefit. Adaptations might be achieved through the reduction of irradiated volumes using proton therapy, non-ionising diagnostic procedures, image guidance, and minimal stray radiation. Non-ionising imaging should become more systematic. Radiotherapy approaches that might result in a lower probability of misrepaired DNA damage (eg, particle therapy biology and tumour targeting) are an area of investigation.

Choroid Plexus Tumors in Children: Long-Term Follow-Up of Consecutive Single-Institutional Series of 59 Patients Treated over a Period of 8 Decades (1939-2020)

OBJECTIVE

To present long-term follow-up of a consecutive single-institutional series of patients treated for choroid plexus tumors over 8 decades.

METHODS

From 1939 to 2020, 59 children were treated for choroid plexus tumors. Median age at diagnosis was 1.7 years.

RESULTS

Gross total resection was achieved in 51 patients (86%). Ten patients (17%) underwent >1 resection. During the first 4 decades of the study (1939-1979), 14 patients with plexus papillomas were treated. Operative mortality was 50%, with 6 of the remaining 7 patients experiencing excellent survival with follow-up periods of 41-81 years. In the last 4 decades (1980-2020), 38 patients had low-grade tumors, and all were alive at the latest follow-up (range, 0.5-39 years). Observed 5-year survival in this subgroup was 100% (n = 30), as was observed 10-year survival (n = 26). One of 7 (14%) patients with atypical choroid plexus papilloma and 3 of 31 patients (10%) with choroid plexus papilloma underwent a second resection owing to recurrent tumor. At last follow-up, 47 patients (80%) were alive; 45 (96%) had a Barthel Index score of 100 and 2 had a Barthel Index score of 50. Today 25 patients are adults (20-59 years old); 17 work full-time, 4 work part-time, and 4 are unable to work.

CONCLUSIONS

Low-grade choroid plexus tumors can be cured with gross total resection alone, with excellent long-term survival and functionality. The vast majority of survivors live independently as adults and work full-time. Recurrences are uncommon (8.7%), appear within the first few years after primary surgery, and can be treated with repeat resections.

Primary intraventricular tumors - Imaging characteristics, post-treatment changes and relapses

Primary intraventricular neoplasms are rare tumors that originate from the ependymal or subependymal, septum pellucidum, choroid plexus and the supporting arachnoid tissue. Knowledge of the common locations of these tumors within the ventricular system, together with key imaging characteristics and presentation age, can significantly narrow the differential diagnosis. In 2016, the WHO reorganized the classification of several primary CNS tumors by combining histopathological and molecular data. This study highlights the imaging characteristics, histopathological and molecular data, treatment strategies and post-treatment changes of primary intraventricular tumors. Molecular-based diagnosis can not only aid in patient stratification and personalized treatment, but it can also provide prognostic and predictive value independent of WHO classification.

Choroid Plexus Carcinomas With TP53 Germline Mutations: Management and Outcome

Background

Choroid plexus carcinomas (CPCs) are rare pediatric tumors commonly associated with Li-Fraumeni syndrome (LFS), which involves a germline mutation of the tumor suppressor gene TP53.

Materials and Methods

We retrospectively analyzed the corresponding information of 12 cases, including the effects of surgery and radiotherapy and TP53 germline mutations, to analyse the management strategies. Kaplan-Meier curves and the log-rank test were used to evaluate the progression-free survival (PFS).

Results

Twelve CPC patients were included, of which TP53 germline mutations were found in eight cases. All patients underwent surgical resection, and six patients received radiotherapy following with operation after initial diagnosis, one patient received radiotherapy following relapse. It was significantly different (P=0.012 and 0.028) that patients with TP53 germline mutation receiving the gross total resection (GTR) without radiotherapy showed survival advantages. Without TP53 germline mutations also showed survival advantages, but there is no statistical significance (P=0.063)

Conclusions

These findings provide evidence for the therapeutic strategy that radiotherapy should not be considered for patients with TP53 germline mutations.

Paediatric atypical choroid plexus papilloma: is adjuvant therapy necessary?

INTRODUCTION

Choroid Plexus Tumours (CPTs) account for 1-4% of all brain tumours in children. Atypical choroid plexus papillomas (aCPPs) are a subset of these tumours, defined over a decade ago, yet no consensus exists on the optimal approach to their management.

METHODS

We conducted a retrospective analysis of all patients treated for CPTs at the Hospital for Sick Children between January 1, 2000, and December 31, 2018, and focused on patients with aCPP. Data extracted from the patient records for analysis included: demographic and clinical features, radiological imaging, surgical and adjuvant therapies, key pathological features, immunohistochemical staining for TP53 and tumour karyotype. Six of seven aCPP samples were profiled using Illumina HumanMethylationEPIC arrays and the top 10,000 most variably methylated probes were visualized using tSNE. Copy number inferencing was also performed.

RESULTS

Twenty-nine patients were diagnosed with CPT, seven of whom had a diagnosis of aCPP as confirmed by histological review. Methylation profiling demonstrated that aCPPs clustered with both choroid plexus papillomas (CPPs) and choroid plexus carcinomas (CPCs). Complete resection of the tumour was pursued in all cases of aCPP and no patient received adjuvant therapy. All aCPP patients were alive at last follow up.

CONCLUSIONS

This limited case series suggests that paediatric aCPP can be successfully managed with surgical resection alone, followed by a 'watch and wait' approach thus avoiding adjuvant therapies. A deeper understanding of the biology of aCPP is required to identify objective markers which can help provide robust risk stratification and inform treatment strategies.

Long-Term Outcome After Surgical Resection of a Spinal Choroid Plexus Tumor in a Dog

A 6 yr old castrated male Clumber spaniel was referred for evaluation of acute paraplegia. MRI of the thoracolumbar spine demonstrated an intradural-extramedullary mass lesion at the level of T12 and extradural spinal cord compression at L1-L2. A hemilaminectomy was performed to achieve gross total resection of the mass lesion and removal of extruded disc material. A diagnosis of spinal choroid plexus tumor (CPT) and intervertebral disc extrusion was made. At 4 mo postoperatively, MRI demonstrated a mass lesion at the right lateral aperture of the fourth ventricle. Spinal drop metastasis from a primary intracranial CPT was suspected. The dog was ambulating independently and neurologically normal at that time. At 17 mo postoperatively, a third MRI was performed owing to decreased postural reactions in both hind limbs and vision loss in the right eye, and it demonstrated an increase in size of the intracranial mass lesion. These two additional MRI studies of the entire central nervous system showed no other metastatic lesions nor any evidence of local recurrence. At 25 mo postoperatively, the dog died at home. This is the first case report of surgical intervention and antemortem histopathological diagnosis of a spinal CPT in a dog.

Extraventricular Choroid Plexus Carcinoma with Spinal Metastasis: A Case Report

We report a case of extraventricular choroid plexus carcinoma (CPC) accompanied by spinal metastasis in a pediatric patient. A 15-year-old female patient presented with chronic progressive headache and blurry vision. Magnetic resonance imaging (MRI) revealed an intra-axial mass in the left frontal lobe. A gross total resection was performed, and the histopathological examination revealed the diagnosis of CPC, confirmed with immunohistochemical (IHC) analysis of GFAP, S100, EM, P53 and Ki67. Eleven months later, MRI result identified another mass in the left frontal lobe. Spinal MRI showed drop metastasis to the spine, accompanied by leptomeningeal seeding. This case demonstrated the importance of IHC and spinal MRI in the management of CPC. This case report may provide more insight into extraventricular CPC cases, which is important for the adequate management of patients with CPC in the future.

Stereotactic Radiosurgery for Choroid Plexus Tumors: A Report of the International Radiosurgery Research Foundation

BACKGROUND

Choroid plexus tumors (CPT) are rare epithelial tumors of the choroid plexus. Gross total resection (GTR) may be curative, but it is not always possible.

OBJECTIVE

To evaluate the role of Gamma Knife stereotactic radiosurgery (GKSRS) as either a primary or adjuvant management option for WHO grade I-III CPT through a multicenter project.

METHODS

A total of 32 patients (20 females) with a total of 43 treated tumors were included in the analysis. A total of 25 patients (78%) had undergone initial surgical resection. The median total tumor volume was 2.2 cc, and the median margin and maximum doses were 13 and 25.5 Gy, respectively.

RESULTS

Local tumor control was achieved in 69% of cases. Local tumor progression-free survival (PFS) rate for low-grade tumors at 1, 3, and 5 yr was 90%, 77%, 58%, respectively. The actuarial local tumor PFS rate for high-grade tumors at 1, 3, and 5 yr was 77%, 62%, and 62%, respectively. There was no significant difference in local tumor control rates between low- and high-grade CPT (P = .3). Gender, age, and degree of resection were not associated with treated tumor PFS. Distant intracranial spread developed in 6 patients at a median of 22 mo after initial SRS. Actuarial distant brain tumor PFS rate at 1, 2, 5, and 10 yr was 93%, 88%, 78%, and 65%, respectively. Three patients (9%) developed persistent symptomatic adverse radiation effects at a median of 11 mo after the procedure.

CONCLUSION

GKSRS represents a minimally invasive alternative management strategy for imaging defined or surgically recurrent low- and high-grade CPT.

CSF Rhinorrhea: A Rare Clinical Presentation of Choroid Plexus Papilloma

Choroid plexus papilloma (CPP) is a rare brain tumour occurring mostly in infants and children. Most CPPs are intraventricular and present with symptoms and signs of increased intracranial pressure (ICP). This case report describes a middle-aged female who presented with spontaneous cerebrospinal fluid (CSF) rhinorrhea from a tumour located in the cerebellopontine angle (CPA). She underwent craniotomy with subtotal tumour resection and remained progression and rhinorrhea-free for several years. Upon clinical progression, the patient was treated with Cyberknife stereotactic radiosurgery. The patient clinically improved and demonstrated a favourable radiologic response to radiosurgery.

Management of choroid plexus tumours: A comprehensive study from a tertiary hospital

OBJECTIVE

Choroid plexus tumours (CPT) are rare intraventricular tumours representing less than 0.5 % of brain tumours. The tumour is commonly located in the supratentorial region, but the location varies depending on the age. We present our experience of managing these tumours in a tertiary hospital.

METHODS

Retrospectively, we reviewed our operative database and recruited 80 cases of CPT who underwent surgical treatment in our institute from 1995 to 2018. We analysed the factors affecting the outcome and the perioperative complications of the choroid plexus tumour.

RESULTS

A total of 80 choroid plexus tumours were recruited in our retrospective review, of which 44 were choroid plexus papilloma (CPP), 13 were atypical choroid plexus tumours (ACPP), 23 were choroid plexus carcinomas (CPC). The mean age was 16.75 (SD 16.71) in the overall cohort. Males were found to be predominant in all tumour groups (M/F: 46/34). Headache was the most common symptom (52.5 %). Hydrocephalus was seen in 53.8 % of cases. The median overall survival was 89.88 months. Gross total resection was achieved in 62.5 % cases (n = 50/80), and near-total resection in 27. 5 % cases (n = 22/80). The median overall survival was 89.88 months. The median overall survival for CPP, ACPP, CPC was 106.83, 37.37, 36.19 months, respectively. Median Event-free survival was 65.83 months. A Cox regression analysis of predictors of overall survival of atypical CPP and CPC was done, in which age, sex, location, size, the extent of the resection, and complications were considered. The extent of the resection (p = 0.01) and the size (p = 0.02) were related to overall survival CONCLUSION: CPT's are the rare intraventricular tumours, which requires aggressive resection strategies. The extent of resection offers survival benefit based on the histological grades.

Pediatric atypical choroid plexus papilloma: Clinical features and diagnosis

OBJECTIVE

Atypical choroid plexus papilloma (aCPP) is a newly introduced subtype of choroid plexus tumors (CPTs) defined by the World Health Organization (WHO) in 2007 and is characterized by intermediate characteristics between choroid plexus papilloma (CPP) and choroid plexus carcinoma (CPC). Currently, the available data describing the clinical features of aCPP in children are limited.

METHODS

We performed a retrospective review of 24 pediatric patients with CPTs in our institute and focused on the clinical, radiological and histopathological features of 9 patients with aCPP.

RESULTS

The median age of aCPP patients was 12 (3-144) months, which was younger than the age of CPP patients (36 (5-132) months, P < 0.05). Of the 9 aCPPs, there were 4 cases of giant masses in the cerebral hemisphere, which was significantly higher than that in CPPs (44.4 % vs 0.0 %, P < 0.05). According to MRI analysis, cysts and necrosis (66.7 % vs 16.7 %, P < 0.05), peritumoral edema (55.6 % vs 8.3 %, P < 0.05) and blurred borders (55.6 % vs 8.3 %, P < 0.05) were more common in aCPPs than in CPPs. T1WI isointense signals were mainly observed in aCPPs and CPPs (aCPP66.7 % vs CPP58.3 %, P >0.05), while T2WI slightly low signals were more common in CPPs (CPP41.7 % vs aCPP0%, P < 0.05); moreover, the tumor volume of aCPPs was significantly larger than that of CPPs (aCPP78.3 cm3 vs 8.4 cm3, P < 0.05). For the DWI sequence scans, isointense signals were more common in aCPPs (aCPP77.8 %>CPP25.0 %, P < 0.05), while slightly low signals were more common in CPPs (CPP58.3 %>aCPP0%, P < 0.05). Both aCPPs and CPPs mainly showed homogeneously strong enhancement (aCPP66.7 % vs CPP91.7 %, P > 0.05). Interestingly, 1 aCPP showed annular enhancement. For the pathological and immunohistochemical studies, the Ki67 proliferation index was significantly higher in aCPPs than in CPPs (13 % vs 6%, P < 0.05), and the S-100(+)/Vim(+)/Syn(+) positive rate was higher in aCPPs (58.3 % vs 11.1 %, P < 0.05).

CONCLUSIONS

aCPP shows some distinctive clinical features compared with CPP, such as younger age, larger tumor size, more frequent necrosis and peritumoral edema, blurred borders, slightly low signals on T2WI and isointense signals on DWI, and a higher S-100(+)/Vim(+)/Syn(+) positive rate, which may provide more valuable evidence for differential diagnosis and clinical decisions surrounding aCPP.

Transcallosal Removal of a Choroid Plexus Tumor From the Lateral Ventricle in a Dog. Case Report

A 6-years-old female Staffordshire terrier was referred for periodic generalized seizures and asymmetric visual deficits. Magnetic resonance imaging revealed a 23.2 × 19.3 × 23.0 mm soft tissue mass within the right lateral ventricle and consequential dilatation of the lateral ventricles. Surgically, an interhemispheric approach was performed next to the marginal gyrus after a right parieto-parasagittal craniotomy, and a large choroid plexus tumor was transcallosally removed. After 3 days, the dog was discharged to home, and supportive treatment was continued. Histology revealed a choroid plexus papilloma, which was also confirmed by immunohistochemistry. One month after surgery, a control MRI showed that the ventricles were still dilated, but there was no sign of recurrent tumor. The dog had two additional seizures at home during the month following the intervention and one more grand mal episode was observed 4 months after the surgery. Nine months after the surgery, the dog showed no seizure activity, but her vision had not yet returned.

Role of available adjuvant therapies following surgical resection of atypical choroid plexus papilloma-a systematic review and pooled analysis

Background

Atypical choroid plexus papilloma is a recently introduced entity with intermediate pathological characteristics. These tumors are relatively rare and the optimal management of these tumors is a matter of debate. Therefore, we performed a systematic review and pooled analysis about the effects of adjuvant therapies on outcome measures of these patients. We also compared these effects on totally and partially resected tumors and pediatric and adult populations.

Methods

A systematic search of 3 databases based on inclusion/exclusion criteria was performed. Data extraction was separately performed by 2 authors, and the summarized data were presented in the form of tables. Pooled estimates of different outcome measures were calculated for each adjuvant therapy and presented separately for studies with pediatric, adult, or mixed populations.

Results

A review of 14 included studies consisting of 144 patients revealed the effect of adjuvant treatment on reduction of tumor recurrence, metastasis, and reoperation rates and increasing survival rates in patients with subtotal tumor resection. This advantage was not seen in the case of gross total tumor resection. Almost all outcome measures were more favorable in the pediatric population.

Conclusions

It can be concluded that whenever gross total resection is not feasible, the implementation of adjuvant therapy can improve the outcome and prognosis. In other cases, it should be decided on an individual basis. Also, more aggressive behavior and higher rates of recurrence and mortality in the adult population suggest the consideration of more aggressive adjuvant treatments for adult patients.

A Rare Case of Choroid Plexus Papilloma of the Third Ventricle in an Adult

Colloid cysts are the commonest masses of the third ventricle. Third ventricle neoplasms are uncommon. They include tumors arising from the choroid plexus (papillomas, carcinomas), tumors arising from other than the choroid plexus (ependymomas, meningiomas), metastases, and lymphoma. Choroid plexus tumors usually occur in the lateral ventricle in children and fourth ventricle in adults, and often present with hydrocephalus. We herein describe the extremely rare occurrence of third ventricle choroid plexus papilloma in a 35-year-old man who presented to the emergency department with a long history of intermittent headaches, occasionally associated with photophobia. CT and MR imaging revealed a lobulated ovoid lesion in the third ventricle with minimal extension into the right lateral ventricle through the foramen of Monro, causing mild ventricular dilatation. Surgical resection was performed and histopathology revealed choroid plexus papilloma.

Progress in rare central nervous system tumors

PURPOSE OF REVIEW

Although all primary central nervous system (CNS) tumors are rare, certain tumor types each represent less than 2% of the total and an annual incidence of about 1000 patients or less. Most of them are disproportionally diagnosed in children and young adults, but older adults can also be affected and are rarely recruited to clinical trials. Recent new molecular techniques have led to reclassification of some of these tumors and discovery of actionable molecular alterations.

RECENT FINDINGS

We review recent progress in the molecular understanding and therapeutic options of selected rare CNS tumors, with a focus on select clinical trials (temozolomide and lapatinib for recurrent ependymoma; vemurafenib for BRAFV600E-mutated tumors), as well as tumor-agnostic approvals (pembrolizumab, larotrectinib) and their implications for rare CNS tumors.

SUMMARY

Although rare CNS tumors are a very small fraction of the total of cancers, they represent a formidable challenge. There is a need for dedicated clinical trials with strong correlative component in patients of all ages with rare CNS tumors. Critical research questions include relevance of the selected target for specific tumor types, persistence of the actionable biomarker at recurrence, blood-brain barrier penetration, and analysis of mechanisms of primary and acquired resistance.

Infratentorial choroid plexus tumors in children

OBJECTIVE

Choroid plexus tumors (CPTs) are rare pediatric intracranial neoplasms, and mostly occur in the lateral ventricle. CPTs located in the infratentorial location are considered to be rare in the pediatric population. We present a series of eight patients treated in the last decade at our institution focusing on clinical presentations and their outcome after excision.

METHODS

We performed an institutional retrospective review of patients who underwent surgical resection of infratentorial CPTs during the period from 2008 to 2017. Patients' charts were reviewed for demographic data, clinical presentation, surgical treatment, and follow-up.

RESULTS

There were eight patients (6 females and 2 males), with mean age for the cohort at presentation was 9.0 years. They represent 75% of 12 CPTs of all locations treated at the same period in our institution. These 8 infratentorial CPTs were in the fourth ventricle in seven, and in the cerebellopontine angle (CPA) in one. Seven patients had choroid plexus papillomas (WHO grade I) and 1 had an atypical choroid plexus papilloma (WHO grade II). Gross total resection was attempted in all patients. However, two of 3 patients with fourth ventricle floor invasion had subtotal resection with a thin layer of tumor left on the floor. The remaining 6 had a gross total resection. Six patients with preoperative hydrocephalus had a perioperative external ventricular drainage but none required permanent shunting after tumor resection. None showed recurrence/tumor progression without adjuvant therapy during the follow-up period of 20 months to 11 years.

CONCLUSION

Infratentorial dominance among pediatric CPTs in this series contradicts previous reports. Infratentorial CPTs are amenable to surgical resection. Unresected small residuals due to invasion to the fourth ventricle floor showed no regrowth during 2 to 3 years follow-up without adjuvant therapy. However, these patients with incomplete resection need watchful observations.

ENDOSCOPIC ASSISTED, TRANSFONTANELLE EXCISION OF A LARGE THIRD VENTRICULAR ATYPICAL CHOROID PLEXUS PAPILLOMA IN AN INFANT

Choroid plexus papillomas are rare benign tumours, which are found in both adult and paediatric age groups. The 'atypical' histological subclass is rarer still. The commonest site of occurrence is in the lateral ventricles; rare locations are the cerebellopontine angle and the third ventricle. The goal of care is a gross total excision of the tumour. The histologic subtype determines further adjuvant care given to the patient. The outcome of the care of these patients depends on the histological grade, extent of surgical resection adjuvant care. We present a case of a 12 week-old infant with obstructive hydrocephalus, secondary to a third ventricular atypical choroid plexus papilloma. He had a 'two-staged' resection of the choroid plexus papilloma, using an endoscopic access via the right Kocher's point in the right anterior fontanelle, in the same position as that proposed for access in endoscopic third ventriculostomy because of the observed sutural diastasis. Histology confirmed an atypical choroid plexus papilloma. He made progressive recovery post-surgery but unfortunately there has been default with follow-up clinic visits.