Atypical Choroid Plexus Tumor of the Cauda Equina With Metastases to the Spinal Cord and Brain.

We report a case of a 57-year-old man with a tumor arising from the cauda equina with spinal cord and intracranial metastases in the basal cisterns and along the cranial nerves. He presented with severe lower back pain and mild gait imbalance. His imaging revealed a large mass in the lumbosacral region with involvement of the cauda equina, intradural extramedullary enhancing metastases in the thoracic spinal canal, and intracranial metastases in the suprasellar cistern and along both trigeminal and facial/vestibulocochlear nerve complexes. Pathological examination of the resected thoracic spinal cord mass showed an atypical papillary proliferation with moderate nuclear pleomorphism and rare mitotic figures. While the morphologic and immunophenotypic features were consistent with the diagnosis of a choroid plexus tumor, the atypical location for this entity required the exclusion of other epithelioid tumors with papillary architecture. Additional immunohistochemical markers were used to exclude a metastatic adenocarcinoma, a papillary variant of a meningioma, and a papillary variant of an ependymoma. Ultimately, methylation-based tumor profiling determined that the methylation class was a match for "plexus tumor" resulting in the integrated diagnosis of the tumor with features of choroid plexus papilloma. This is a unique presentation for both the location and the metastatic spread. The methylation profile was instrumental in establishing this diagnosis.

Molecular genetics and diversity of choroid plexus tumors.

Choroid plexus tumors are rare intraventricular brain tumors predominantly arising in children but also affecting adults. Chromosome-wide copy-number alterations and TP53 mutations do occur, but in most choroid plexus tumors, driver mutations have not been identified. Here we give a brief overview of the histopathological and clinical diversity of choroid plexus tumors and their genetic and epigenetic heterogeneity. Preliminary data indicate that choroid plexus carcinomas comprise at least 2 epigenetic subgroups, one of which is associated with TP53 mutation status. These findings strongly encourage us to further investigate the genetic and epigenetic heterogeneity in a larger cohort and to align molecular subgroup status with clinical annotations, in order to identify prognostic markers that may also aid stratification within future international trials.

Comprehensive multiomics analysis reveals distinct differences between pediatric choroid plexus papilloma and carcinoma.

Choroid plexus tumors (CPTs) are intraventricular tumors derived from the choroid plexus epithelium and occur frequently in children. The aim of this study was to investigate the genomic and epigenomic characteristics of CPT and identify the differences between choroid plexus papilloma (CPP) and choroid plexus carcinoma (CPC). We conducted multiomics analyses of 20 CPT patients including CPP and CPC. Multiomics analysis included whole-genome sequencing, whole-transcriptome sequencing, and methylation sequencing. Mutually exclusive TP53 and EPHA7 point mutations, coupled with the amplification of chromosome 1, were exclusively identified in CPC. In contrast, amplification of chromosome 9 was specific to CPP. Differential gene expression analysis uncovered a significant overexpression of genes related to cell cycle regulation and epithelial-mesenchymal transition pathways in CPC compared to CPP. Overexpression of genes associated with tumor metastasis and progression was observed in the CPC subgroup with leptomeningeal dissemination. Furthermore, methylation profiling unveiled hypomethylation in major repeat regions, including long interspersed nuclear elements, short interspersed nuclear elements, long terminal repeats, and retrotransposons in CPC compared to CPP, implying that the loss of epigenetic silencing of transposable elements may play a role in tumorigenesis of CPC. Finally, the differential expression of AK1, regulated by both genomic and epigenomic factors, emerged as a potential contributing factor to the histological difference of CPP against CPC. Our results suggest pronounced genomic and epigenomic disparities between CPP and CPC, providing insights into the pathogenesis of CPT at the molecular level.

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.

An Illustrated Scoping Review of the Magnetic Resonance Imaging Characteristics of Canine and Feline Brain Tumors.

Magnetic resonance imaging (MRI) is used pervasively in veterinary practice for the antemortem diagnosis of intracranial tumors. Here, we provide an illustrated summary of the published MRI features of primary and secondary intracranial tumors of dogs and cats, following PRISMA scoping review guidelines. The PubMed and Web of Science databases were searched for relevant records, and input from stakeholders was solicited to select data for extraction. Sixty-seven studies of moderate to low-level evidence quality describing the MRI features of pathologically confirmed canine and feline brain tumors met inclusion criteria. Considerable variability in data inclusion and reporting, as well as low case numbers, prohibited comparative data analyses. Available data support a holistic MRI approach incorporating lesion number, location within the brain, shape, intrinsic signal appearances on multiparametric sequences, patterns of contrast enhancement, and associated secondary changes in the brain to prioritize differential imaging diagnoses, and often allows for accurate presumptive diagnosis of common intracranial tumors. Quantitative MRI techniques show promise for improving discrimination of neoplastic from non-neoplastic brain lesions, as well as differentiating brain tumor types and grades, but sample size limitations will likely remain a significant practical obstacle to the design of robustly powered radiomic studies. For many brain tumor variants, particularly in cats, there remains a need for standardized studies that correlate clinicopathologic and neuroimaging data.

Pediatric-Like Brain Tumors in Adults.

Pediatric brain tumors are different to those found in adults in pathological type, anatomical site, molecular signature, and probable tumor drivers. Although these tumors usually occur in childhood, they also rarely present in adult patients, either as a de novo diagnosis or as a delayed recurrence of a pediatric tumor in the setting of a patient that has transitioned into adult services.Due to the rarity of pediatric-like tumors in adults, the literature on these tumor types in adults is often limited to small case series, and treatment decisions are often based on the management plans taken from pediatric studies. However, the biology of these tumors is often different from the same tumors found in children. Likewise, adult patients are often unable to tolerate the side effects of the aggressive treatments used in children-for which there is little or no evidence of efficacy in adults. In this chapter, we review the literature and summarize the clinical, pathological, molecular profile, and response to treatment for the following pediatric tumor types-medulloblastoma, ependymoma, craniopharyngioma, pilocytic astrocytoma, subependymal giant cell astrocytoma, germ cell tumors, choroid plexus tumors, midline glioma, and pleomorphic xanthoastrocytoma-with emphasis on the differences to the adult population.

Tractography Navigated Endoscopic En-Bloc Excision of Pediatric Giant Choroid Plexus Tumor.

Giant choroid plexus (CP) tumors in children pose a formidable surgical challenge due to extensive vascularity/blood loss, tumor size impeding early visualization of the pedicle, hydrocephalus/mass effect distorting cerebral localization, considerable prevalence of atypical tumors and carcinoma demanding excision without tumor spillage, and retraction-associated morbidity. However, total resection of CP papilloma has excellent potential for cure. This is probably the first report in the literature of diffusion tensor imaging navigation-guided tumor pedicle targeting, endoscopic devascularization and division of pedicle followed by en bloc delivery in optimally tackling most of these challenges in a 6-year-old girl presenting with a giant lateral ventricular CP tumor. Giant CP tumors pose a formidable challenge. Extensive vascularity can cause life-threatening blood loss in children.1 Large tumor size makes it impractical during microsurgery to achieve early visualization of pedicle.2 Hydrocephalus and mass effect can distort sulcal anatomy, with potentially devastating deficits.3 Still, prevalence of atypical tumors and carcinoma warrants excision without tumor spillage.4 In Video 1, we demonstrate our "10-D" steps of en-bloc excision, exploiting panoramic visualization of endoscope5: 1. Diagnosis, 2. Diffusion tensor imaging guided pedicle targeting, 3. Design position & exposure, 4. Durotomy, 5. Dissection of sulcus, 6. Delineation of pedicle, 7. Devascularization, 8. Division of pedicle, 9. Delivery of tumor, and 10. Dural & skin closure. The conventional superior parietal lobule approach to get the tumor en-bloc would have been from the posterosuperior direction, where the tumor is likely to conceal the pedicle. The trajectory to first get to the pedicle must be from an anterosuperior direction but will violate corticospinal fibers. Hence entry point was chosen in between, just posterior to the post-central sulcus. To accommodate the 'en-bloc' excision avoiding ventricular seedlings, a 5 cm mini-craniotomy was fashioned centered on the entry point planned in the navigation system. Ventricle was entered perpendicular to the sulcus through the roof of the atrium, with least cortical transgression and avoiding injury to laterally placed optic radiation and speech areas.6 A 30-degree, 4-mm endoscope was inserted anterolateral to the tumor and fixed. The wide-angled vision offered by endoscopes enhancing meticulous dissection is the likely cause of better neurological outcomes, as noted in other ventricular lesions.7 Pedicular attachment of the tumor is coagulated thoroughly and cut, ensuring initial sparing of venous drainage. The draining vein is then coagulated and divided. 'En-bloc' excision is also known in other vascular lesions to decrease the risk of bleeding.8 The angled optics & panoramic visualization helps to identify any possible tumor seedlings.9 This is probably the first report of endoscopic en-bloc excision of a giant choroid plexus tumor in literature.

Clinical, magnetic resonance imaging, and histological description of a choroid plexus papilloma with disseminated intraventricular and spinal cerebrospinal fluid drop metastases in a young adult dog: a case report.

A 2-year-old male entire Cane Corso was presented for investigations into a 1-week history of ambulatory paraparesis and pelvic limb ataxia gradually deteriorating. Magnetic resonance imaging (MRI) revealed intraventricular space-occupying lesions affecting the fourth ventricle and lateral apertures and intradural-extramedullary space-occupying lesions at the level of C7 vertebra, L4-L5, and L7-S1 intervertebral disk spaces. Due to poor quality of life, the patient was euthanized. A post-mortem examination revealed partially encapsulated, multifocally infiltrative, and moderately cellular neoplastic masses. The histological description was similar for all masses. The cells appeared cuboidal with round central nuclei and a moderate amount of eosinophilic cytoplasm and were arranged almost exclusively in single-layered papilliform patterns supported by a fibrovascular stroma. Mitoses were rarely observed (1/2.37 mm2). The primary neoplasm was morphologically most consistent with a choroid plexus papilloma despite drop metastases. This is the first report of a histologically confirmed primary ventricular choroid plexus papilloma causing disseminated MRI-apparent intraventricular and spinal drop metastases.

Choroid plexus papilloma in a mature cystic teratoma of ovary: A rare case report.

Mature cystic teratoma of the ovary is the most common type of germ cell tumor. It constitutes approximately 20% of all ovarian neoplasms. As a rare occurrence, however, several types of benign and malignant tumours developing secondarily in dermoid cysts have been reported. Those of central nervous origin are almost exclusively gliomas of astrocytic, ependymal or oligodendroglial lineage. Choroid plexus tumors are unusual intracranial tumors which comprised of only 0.4-0.6% of all brain tumors. These are neuroectodermal in origin and similar in structure to a normal choroid plexus in the form of multiple papillary fronds mounted on a well vascularized connective tissue stroma. The present case report highlights the presence of a choroid plexus tumor in a mature cystic teratoma of the ovary in a 27-year-old woman who came for safe confinement and cesarean section.

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.

Solitary intraventricular tumors in dogs and cats treated with radiotherapy alone or combined with ventriculoperitoneal shunts: A retrospective descriptive case series.

BACKGROUND: Intraventricular tumors are rare, optimal treatment is not defined. Symptomatic patients often exhibit life-threatening hydrocephalus. With several months time-to-effect after radiotherapy (RT), increased intracranial pressure is concerning. This increase in pressure can be overcome by ventriculoperitoneal shunting (VPS). OBJECTIVES: Retrospective evaluation of outcome and complications in dogs and cats with intracranial tumors treated with either RT or VPS/RT. ANIMALS: Twelve client-owned cats and dogs. METHODS: Dogs and cats with symptomatic intraventricular tumors treated with definitive-intent RT or VPS/RT were included in a retrospective, descriptive case series. Complications, tumor volume evolution, time-to-progression, and survival time were determined. RESULTS: Twelve animals were included: 1 cat and 5 dogs treated with single-modality RT and 4 cats and 2 dogs treated with VPS/RT. Neurological worsening seen in 4/6 animals during single-modality RT and 2/6 died during RT (suspected brain herniation). All dogs with VPS normalized clinically by the end of RT or earlier. Complications occurred in 4/6 animals, all but 1 were successfully managed surgically. Imaging follow-up in 8 animals surviving RT showed a marked decrease in tumor volume. Median survival time was 162 days (95% confidence interval [CI]: 16; infinity) for animals treated with RT and 1103 days (95%CI: 752; infinity) for animals treated with VPS/RT. Median time-to-progression was 71 days (95%CI: 7; infinity) and 895 days (95%CI: 704; infinity) for each group, respectively. Two dogs died because of intraventricular metastasis 427 and 461 days after single-modality RT. CONCLUSIONS AND CLINICAL IMPORTANCE: Ventriculoperitoneal shunting led to rapid normalization of neurological signs and RT had a measurable effect on tumor volume. Combination of VPS/RT seems to be beneficial.

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.

Case Report: Ventriculoperitoneal Shunting and Radiation Therapy Treatment in a Cat With a Suspected Choroid Plexus Tumor and Hypertensive Hydrocephalus.

A 14-year-old male neutered domestic short-hair cat was presented for a history of behavioral changes and episodes of urinary retention. Neurological examination was consistent with a multifocal intracranial neuroanatomical localization, with suspected right sided lateralisation and suspected raised intracranial pressure (ICP). Brain magnetic resonance imaging (MRI) revealed an intraventricular multilobulated well-defined T2W-hyperintense and T1W-isointense, markedly contrast enhancing mass lesion within the dorsal aspect of the III ventricle extending into the left lateral ventricle, causing hypertensive obstructive hydrocephalus. A ventriculoperitoneal shunt (VPS) was placed within the left lateral ventricle, followed by a radiation therapy (RT) course of 45 Gy total dose in 18 daily fractions. Six-months post-RT, computed tomography revealed mild reduction in mass size and resolution of the hydrocephalus. The patient was neurologically normal with no medical treatment. Raised ICP causes severe clinical signs, can lead to brain ischaemia and herniation, and significantly increases anesthetic risk during RT. Placement of a VPS in cats with hypertensive obstructive hydrocephalus may allow improvement of neurological signs due to raised ICP, and therefore making the patient a more stable candidate for anesthesia and radiation therapy.

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.

Solitary Metastasis of Colon Adenocarcinoma Mimicking Colloid Cyst of the Third Ventricle.

Metastatic lesions to the choroid plexus, although far less common than colloid cysts, can present very similarly both symptomatically and radiographically. Choroid plexus metastases are most common in the lateral ventricles, however, when they occur in the third and fourth ventricles they may cause obstructive hydrocephalus typical of a colloid cyst lesion. Renal cell carcinoma is the most common primary cancer, but many rare primaries have been reported. When patients are presenting with symptoms typical of colloid cysts it is important to consider past oncological history and if past medical history is significant for cancer using MR spectroscopy may be valuable in distinguishing between cystic and metastatic lesions.

Suboccipital Craniotomy and C1 Laminectomy for Atypical Choroid Plexus Papilloma.

Atypical choroid plexus papilloma is a rare pediatric brain tumor that has distinct clinical and pathologic features. In this case, we highlight the diagnosis and management of this rare disease. The details of case positioning and execution are discussed. The case review is utilized as an overview of histopathologic findings, to discuss clinical features of the disease, and to highlight areas warranting further investigation. In particular, we provide insight into the typical clinical course post-treatment.

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.

The genetic landscape of choroid plexus tumors in children and adults.

BACKGROUND: Choroid plexus tumors (CPTs) are intraventricular brain tumors predominantly arising in children but also affecting adults. In most cases, driver mutations have not been identified, although there are reports of frequent chromosome-wide copy-number alterations and TP53 mutations, especially in choroid plexus carcinomas (CPCs). METHODS: DNA methylation profiling and RNA-sequencing was performed in a series of 47 CPTs. Samples comprised 35 choroid plexus papillomas (CPPs), 6 atypical choroid plexus papillomas (aCPPs) and 6 CPCs plus three recurrences thereof. Targeted TP53 and TERT promotor sequencing was performed in all samples. Whole exome sequencing (WES) and linked-read whole genome sequencing (WGS) was performed in 25 and 4 samples, respectively. RESULTS: Tumors comprised the molecular subgroups "pediatric A" (N=11), "pediatric B" (N=12) and "adult" (N=27). Copy-number alterations mainly represented whole-chromosomal alterations with subgroup-specific enrichments (gains of Chr1, 2 and 21q in "pediatric B" and gains of Chr5 and 9 and loss of Chr21q in "adult"). RNA sequencing yielded a novel CCDC47-PRKCA fusion transcript in one adult choroid plexus papilloma patient with aggressive clinical course; an underlying Chr17 inversion was demonstrated by linked-read WGS. WES and targeted sequencing showed TP53 mutations in 7/47 CPTs (15%), five of which were children. On the contrary, TERT promoter mutations were encountered in 7/28 adult patients (25%) and associated with shorter progression-free survival (log-rank test, p=0.015). CONCLUSION: Pediatric CPTs lack recurrent driver alterations except for TP53, whereas CPTs in adults show TERT promoter mutations or a novel CCDC47-PRKCA gene fusion, being associated with a more unfavorable clinical course.

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.

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.