Molecular insights into malignant progression of atypical choroid plexus papilloma

Foramen of Monro choroid plexus papilloma: An extremely rare location managed by endoscopic resection

Choroid plexus papillomas are rare brain neoplasms, primarily observed in children, and typically manifest with symptoms indicative of heightened intracranial pressure and cerebral irritation. In addition, the tumor's localization varies with the patient's age, and diagnostic and therapeutic approaches predominantly rely on imaging findings and surgical interventions, with histopathological examination being essential for confirmation. This study outlines a unique instance of choroid plexus papilloma in a 30-year-old female, who presented with severe headache and vomiting, subsequently revealing hydrocephalus on Brain CT. Remarkably, the tumor was identified in the Foramen of Monro, an exceedingly rare and unreported location in adults. Notably, the patient underwent successful endoscopic resection without complications, a technique sparsely documented in similar cases. Choroid plexus papilloma, predominantly afflicting children, displays varied tumor locations depending on the patient's age. Our report highlights an exceptional case with an atypical tumor location that was not reported before to our knowledge, and addressed through an innovative endoscopic resection method that was recently used in the management of such cases. This underscores the importance of considering diverse tumor presentations, as it has a favorable prognosis achievable through management, especially with the increasing number of reported cases. Moreover, it advocates for the adoption of emerging endoscopic approaches, which exhibit promising outcomes.

Diagnosis of choroid plexus papilloma: Current perspectives and future directions

Choroid plexus papilloma (CPP) is a rare, slow-growing, and typically benign brain tumor that predominantly affects children. CPP is characterized by well-defined circular or lobulated masses in the ventricles, leading to symptoms related to increased intracranial pressure and hydrocephalus. CPP diagnosis relies on a combination of clinical presentation, imaging findings, and histological examination. The World Health Organization (WHO) classification categorizes choroid plexus tumors into CPP (Grade І), atypical CPP (aCPP, Grade II), and choroid plexus carcinoma (CPC, Grade III). This article reviewed current diagnostics modalities and explored the emergence of new diagnostic methods for CPP. Research on molecular markers and genetic alterations associated with CPP is ongoing, and some potential markers have been identified. These results offered insights into potential therapeutic targets and personalized treatment approaches for CPP. Advancements in radiomics and liquid biopsy hold promise for improving diagnostic accuracy and monitoring treatment outcomes for choroid plexus tumors. Radiomics can provide quantitative data from imaging studies, whereas liquid biopsy can analyze tumor-derived genetic material and molecular markers from body fluids, such as cerebrospinal fluid (CSF) and blood. The rapidly evolving fields of molecular and genetic research and novel diagnostic methods require continuous updates and advancements before their application in clinical practice. We hope that these advancements will lead to earlier and more precise diagnoses, better treatment options, and improved outcomes in patients with CPP and other brain tumors.

Marrow-ablative consolidation chemotherapy and molecular targeted therapy delivered in a risk-adapted manner for newly diagnosed children with choroid plexus carcinoma: A work in progress

Choroid plexus carcinomas (CPC) are early childhood cancers characterized by loss of TP53 function and poor survival. We are analyzing data on TP53 status, survival, and second cancers from the largest cohort of CPC receiving chemotherapy followed by consolidation with marrow-ablative chemotherapy (HDCx). Additionally, we discuss the rationale for targeted therapies for CPC patients. Currently, 8 of the 13 with Li-Fraumeni Syndrome-associated CPC were treated and continued CPC-free, indicating that HDCx improves CPC-free survival in young children with TP53-mutated CPC. These data justify the inclusion of HDCx in the planned prospective international trial for children with TP53-mutated CPC.

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.

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.

Persistence of communicating hydrocephalus post choroid plexus tumor resection: Case reports and review of literature

Background

Hydrocephalus is the most common presentation of choroid plexus tumors; it is thought to be caused either by mass effect obstructing the cerebrospinal fluid pathways or secretory properties of the tumor. In these case reports, we present two cases of choroid plexus tumors with persistence of communicating hydrocephalus postoperatively and review similar reports in the literature.

Case Description

Case 1: a 2-month-old baby girl presented with bulging fontanelle, sunsetting eyes. Magnetic resonance imaging (MRI) showed large third ventricle mass with communicating hydrocephalus. She underwent complete excision of tumor through transcortical approach with perioperative intraventricular hemorrhage. Hydrocephalus persisted postoperatively and the patient required permanent ventriculoperitoneal (VP) shunt. Case 2: a 16-year-old boy presented decreased visual acuity, papilledema, and morning headaches. MRI showed a tumor in the right ventricle and communicating hydrocephalus. He underwent transparietal resection of the tumor. In both cases, hydrocephalus persisted postoperatively and patients required permanent VP shunt. Review of similar cases showed the majority of cases required permanent shunting.

Conclusion

Choroid plexus tumor patients can present with communicating hydrocephalus that may persist post tumor resection for different etiologies. Careful follow-up to determine the need for cerebrospinal fluid diversion through a permanent VP shunt is important.