The goal in this study was to retrospectively evaluate the safety and feasibility of purely neuroendoscopic removal of choroid plexus tumors (CPTs) in children using a monoportal or biportal technique. The clinical, radiological, and surgical data of all children with CPTs removed via purely endoscopic or microsurgical approaches in the last 12 years at two centers were retrospectively reviewed. Both centers were fully equipped with advanced neuroendoscopic technology, and surgical teams were fully trained in complex neuroendoscopic intraventricular surgical procedures. The study involved 32 patients, divided into two groups: 13 undergoing endoscopic procedures and 19 undergoing microsurgical procedures. In the endoscopic group, the mean age was 2.11 years. Eight tumors were located in the lateral ventricles, and 5 in the third ventricle. The mean tumor volume was 6.59 cm3 (range 0.25-15.4 cm3); 9 patients had hydrocephalus at presentation. The monoportal technique was used in 9 patients, and the biportal technique was used in 4 patients. Gross-total removal was achieved in all patients-within a single procedure in 11 patients, and in a two-stage procedure in 2 patients. In the microsurgical group the mean age was 3.75 years. Seventeen tumors were located in the lateral ventricles, and 2 in the third ventricle. The mean tumor volume was 15.07 cm3 (range 1.2-84.35 cm3). The following microsurgical approaches were used: transcortical (n = 11), transcallosal (n = 5), and interhemispheric transprecuneal (n = 3). There was no statistically significant difference between the cases treated via microsurgical and endoscopic approaches with regard to CPT volume (p = 0.06), presence of hydrocephalus (p = 0.22), need for shunt surgery (p = 0.78), or complications (p = 0.06). Furthermore, a statistically significant difference was found in surgery time and blood loss: in endoscopic procedures there was significantly lower blood loss and a shorter surgery time (p < 0.005). The present study conducted at two hospitals has demonstrated that neuroendoscopic removal of the CPT is a safe and feasible alternative to the conventional microsurgical procedure. The lower blood loss, lower rates of serious complications, and full resolution of hydrocephalus are the main points in favor of neuroendoscopic surgery to obtain gross-total removal of intraventricular CPT in infants and children.

Brain metastases are the most common type of brain tumors, typically presenting as intraparenchymal lesions. Intraventricular or choroid plexus involvement is very rare, posing a significant diagnostic challenge. This case report describes a rare instance of a solitary choroid plexus metastasis from a highly well-differentiated lung adenocarcinoma in a 41-year-old woman. The metastatic tumor's close morphological resemblance to a primary choroid plexus tumor added to the diagnostic difficulty, initially leading to a misdiagnosis of choroid plexus carcinoma. However, further investigation, including detailed immunohistochemistry and the detection of a BRAFV600E mutation, ultimately identified the tumor as a metastatic lung adenocarcinoma. Notably, this choroid plexus metastasis served as the index diagnosis, revealing the previously undiagnosed metastatic lung cancer. This case highlights the critical need to consider metastasis in the differential diagnosis of solitary choroid plexus tumors in adults. Recognizing the cytokeratin staining patterns in choroid plexus tumors, along with the use of organ-specific antibodies and molecular analysis, is essential for achieving an accurate diagnosis and ensuring that patients receive the most appropriate and effective treatment.

The patient is a 25-year-old female transferred from an outside facility with week-long complaints of a headache, nausea, and vomiting. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed obstructive hydrocephalus and a large cystic mass of the posterior fossa. Subsequent external ventricular drain placement and surgical resection were performed. The patient was discharged six days postoperatively with resolution of symptoms. Pathological examination of the fleshy component within the cystic structure after surgical resection was relatively inconclusive, with findings suggestive of a choroid plexus tumor. However, the lesion demonstrates the immunohistochemical characteristics of a choroid plexus papilloma (CPP) but with a cystic structure surrounding it. CPPs are rare and typically benign tumors that originate from the choroid plexus, which is responsible for cerebrospinal fluid (CSF) production. These growths can occur throughout the ventricular system of the brain, more commonly in the lateral ventricles and less commonly in the third and fourth ventricles. Differential diagnosis based on imaging is broad due to the shared visual characteristics of various brain tumors. Consequently, immunohistochemical markers are essential for the identification and diagnosis of CPPs. In the case of our patient, the small enhancing nodule is unusual in that it is surrounded by a large cystic lesion. We present the unusual case of a cystic tumor of the posterior fossa with a small nodular component located within, suggestive of a CPP by immunohistochemical and morphological characteristics. A multidisciplinary diagnostic approach is necessary to exact a proper classification of lesions such as this one, including identification by neuroradiology, resection by neurosurgery, and immunohistochemical and morphological analysis by pathology.

Choroid plexus tumors (CPT), especially in pediatric patients, present a major surgical challenge due to their hypervascularity and frequent intraventricular location. Preoperative embolization has emerged as a strategy to minimize intraoperative blood loss and improve surgical outcomes, yet its application in large-volume tumors via the anterior choroidal artery (AChA) remains limited. We report a case of a 10-month-old infant with a giant choroid plexus carcinoma (CPC) measuring 189 cm³, treated with superselective embolization through the AChA using Squid™ prior to surgical resection. A systematic review was also conducted, including 9 studies on preoperative embolization via AChA for CPTs, with attention to technique, tumor volume, agents used, and outcomes. Microcatheterization beyond the plexal point of the AChA enabled safe delivery of the embolic agent, achieving substantial tumor devascularization without ischemic or hemorrhagic complications. Surgical resection was completed without intraoperative blood transfusion or neurological sequelae. The systematic review confirmed the rarity of embolization in tumors exceeding 100 cm³, highlighting our case as one of the largest successfully treated using this approach. Superselective preoperative embolization of choroid plexus tumors via the anterior choroidal artery is technically feasible and safe when performed beyond the plexal point. In high-risk pediatric cases with large-volume tumors, this strategy can significantly improve surgical safety and should be considered as part of a multimodal treatment approach.

Choroid plexus papilloma (CPP) and atypical choroid plexus papilloma (aCPP) have excellent outcomes. However, some CPP/aCPP relapse and may qualify for postoperative adjuvant treatment. German patients from the International CPT-SIOP Registry diagnosed with CPP/aCPP between 2011 and 2023 were included and analysed according to initial staging (postoperative residual tumor [R+], metastases [M+]), biology, postoperative treatment strategy and outcome. Additionally, patients from the published CPT-SIOP-2000 trial (PMID34997889) were combined with the registry cohort for validation purpose. Ninety-three patients were identified (male: n = 53, female: n = 40). Median age at diagnosis was 1.9 (0.1–17.6) years. Initial staging was R0/M0 in n = 61, R+/M0 in n = 24, R0/M + in n = 5 and R+/M + in n = 3. aCPP was diagnosed in n = 38 patients. Molecular subgroup was available for n = 36: ”adult” n = 3, “pediatric A” n = 21 and “pediatric B” n = 12 (6/12 aCPP). Median follow-up was 5.5 (± 0.99) years. Twelve tumors relapsed: R0/M0 n = 4, R+/M0 n = 7, R+/M + n = 1. One patient with relapse died. Most patients did not receive postoperative treatment (n = 88). Five patients (R0/M + n = 2; R+/M + n = 1; R0/M0 n = 2) received postoperative chemotherapy. None was irradiated during first-line treatment. In the enlarged cohort (n = 197), histological diagnosis had a significant impact on PFS (5y-PFS: CPP 90 ± 3.1, aCPP 78.6 ± 4.6, PFS = 0.01). Both, R+ (5y-PFS: R0 90.6 ± 2.6, R + 69.1 ± 7.0, PFS = 0.01) as well as molecular subgroup “pediatric B” (5y-PFS: pediatric A 95.2%±3.3%, pediatric B: 69.5 ± 8.6%, PFS = 0.02), were associated with inferior PFS, especially in aCPP. Incomplete resection and biology impact on PFS especially in aCPP. These results extend the evidence for current stratification and treatment strategies. The online version contains supplementary material available at 10.1007/s11060-025-05136-4.