Myxopapillary ependymoma with pleuropulmonary metastases and high plasma glial fibrillary acidic protein levels

Treatment of Extraneural Metastases of Myxopapillary Ependymomas With Dose-Dense Temozolomide and Lapatinib

Myxopapillary ependymomas (MPEs) are rare tumors of the central nervous system, and outcomes are generally worse with recurrent disease. These tumors can rarely metastasize outside the neuraxis. We present a case of a 35-year-old female with a history of MPEs who developed extraneural metastases 11 years after her initial gross total resection. Sites of metastases included multiple bilateral intrapulmonary and pleural-based masses with pleural effusion and a pelvic mass. The patient was treated with dose-dense TMZ and lapatinib and had a mixed radiographic response after 12 cycles of treatment. This is the first known case of extraneural metastases of MPEs to demonstrate a radiographic response to dose-dense TMZ and lapatinib. This case presentation discusses the need to establish optimal treatment of extraneural ependymal metastases, duration of treatment, and strategy for the management of recurrent diseases.

Convolutional neural network-based magnetic resonance image differentiation of filum terminale ependymomas from schwannomas

PURPOSE

Preoperative diagnosis of filum terminale ependymomas (FTEs) versus schwannomas is difficult but essential for surgical planning and prognostic assessment. With the advancement of deep-learning approaches based on convolutional neural networks (CNNs), the aim of this study was to determine whether CNN-based interpretation of magnetic resonance (MR) images of these two tumours could be achieved.

METHODS

Contrast-enhanced MRI data from 50 patients with primary FTE and 50 schwannomas in the lumbosacral spinal canal were retrospectively collected and used as training and internal validation datasets. The diagnostic accuracy of MRI was determined by consistency with postoperative histopathological examination. T1-weighted (T1-WI), T2-weighted (T2-WI) and contrast-enhanced T1-weighted (CE-T1) MR images of the sagittal plane containing the tumour mass were selected for analysis. For each sequence, patient MRI data were randomly allocated to 5 groups that further underwent fivefold cross-validation to evaluate the diagnostic efficacy of the CNN models. An additional 34 pairs of cases were used as an external test dataset to validate the CNN classifiers.

RESULTS

After comparing multiple backbone CNN models, we developed a diagnostic system using Inception-v3. In the external test dataset, the per-examination combined sensitivities were 0.78 (0.71-0.84, 95% CI) based on T1-weighted images, 0.79 (0.72-0.84, 95% CI) for T2-weighted images, 0.88 (0.83-0.92, 95% CI) for CE-T1 images, and 0.88 (0.83-0.92, 95% CI) for all weighted images. The combined specificities were 0.72 based on T1-WI (0.66-0.78, 95% CI), 0.84 (0.78-0.89, 95% CI) based on T2-WI, 0.74 (0.67-0.80, 95% CI) for CE-T1, and 0.81 (0.76-0.86, 95% CI) for all weighted images. After all three MRI modalities were merged, the receiver operating characteristic (ROC) curve was calculated, and the area under the curve (AUC) was 0.93, with an accuracy of 0.87.

CONCLUSIONS

CNN based MRI analysis has the potential to accurately differentiate ependymomas from schwannomas in the lumbar segment.

Anaplastic myxopapillary ependymoma: A case report and review of literature

BACKGROUND

Myxopapillary ependymoma (MPE) is a pathological grade I tumor that arises in the filum terminale. MPE with anaplastic features is extremely rare, and only 5 cases have shown malignancy at the time of recurrence.

CASE SUMMARY

The patient (a 46-year-old woman) had undergone a MPE operation 30 years ago. After subtotal resection of the tumor located in L4-S1, it had a solid component that extended to the adjacent subcutaneous region. Histologically, the tumor consisted of a typical MPE with anaplastic features. The anaplastic areas of the tumor showed hypercellularity, a rapid mitotic rate, vascular proliferation, and connective tissue proliferation. Pleomorphic cells and atypical mitotic figures were occasionally observed. The MIB-1 index in this area was 12.3%. The immunohistochemical study showed immunoreactivity for vimentin, glial fibrillary acidic protein and S100. The morphological pattern and immunohistochemical profile were consistent with anaplastic MPE. The patient tolerated surgery well without new neurological deficits. She underwent local irradiation for the residual tumor and rehabilitation.

CONCLUSION

Although extremely rare, anaplastic MPE occurs in both pediatric and adult patients, similar to other ependymomas. At a minimum, close monitoring is recommended, given concerns about aggressive biological potential. In the future, further study is needed to determine the WHO classification criteria and genetic indicators of tumor progression. The possibility of malignant transformation of MPE should be taken into account, and patients with MPE should be treated with care and follow-up.

An Insight into Pathophysiological Features and Therapeutic Advances on Ependymoma

Simple Summary

Although biological information and the molecular classification of ependymoma have been studied, the treatment systems for ependymoma are still insufficient. In addition, because the disease occurs infrequently, it is difficult to obtain sufficient data to conduct large-scale or randomized clinical trials. Therefore, this study is intended to emphasize the importance of understanding its pathological characteristics and prognosis as well as developing treatments for ependymoma through multilateral studies.

Abstract

Glial cells comprise the non-sensory parts of the central nervous system as well as the peripheral nervous system. Glial cells, also known as neuroglia, constitute a significant portion of the mammalian nervous system and can be viewed simply as a matrix of neural cells. Despite being the “Nervenkitt” or “glue of the nerves”, they aptly serve multiple roles, including neuron repair, myelin sheath formation, and cerebrospinal fluid circulation. Ependymal cells are one of four kinds of glial cells that exert distinct functions. Tumorigenesis of a glial cell is termed a glioma, and in the case of an ependymal cell, it is called an ependymoma. Among the various gliomas, an ependymoma in children is one of the more challenging brain tumors to cure. Children are afflicted more severely by ependymal tumors than adults. It has appeared from several surveys that ependymoma comprises approximately six to ten percent of all tumors in children. Presently, the surgical removal of the tumor is considered a standard treatment for ependymomas. It has been conspicuously evident that a combination of irradiation therapy and surgery is much more efficacious in treating ependymomas. The main purpose of this review is to present the importance of both a deep understanding and ongoing research into histopathological features and prognoses of ependymomas to ensure that effective diagnostic methods and treatments can be developed.

Subcutaneous Sacro Coccygeal Myxopapillary Ependymoma: A Case Report and a Comprehensive Review of the Literature Reappraising Its Current Diagnostic Approach and Management

Sacrococcygeal myxopapillary ependymoma (MPE) is an uncommon type I glial tumor detected most frequently in the lumbosacral area of adolescents and children. It is usually presented as an intradural ependymal tumor that originates from the filum terminale and other locations within the ventricular system along the craniospinal axis. In rare cases, however, MPE may develop as a primary subcutaneous tumor in the sacrococcygeal area. Tumors can also appear as a dorsal sacrococcygeal growth or subcutaneous nodule. In this case report, we describe a rare case presenting as a subcutaneous sacrococcygeal mass in an elderly female that was subsequently resected and confirmed as subcutaneous MPE. The current standard treatment for MPE is maximal surgical resection with or without postoperative radiotherapy based on the locoregional extent and histological grading. However, there is limited evidence that radiotherapy for oligometastatic foci improves longevity or extends the time to recurrence. In addition to this case report, we provide a comprehensive review of similar cases and case series in the medical literature. Prospective studies evaluating the efficacy of resection and/or radiotherapy are required for improved management of extradural MPE.

Anaplastic Transformation in Myxopapillary Ependymoma: A Report of 2 Cases and Review of the Literature

Myxopapillary ependymoma (MPE) is a relatively common neoplasm arising primarily in the filum terminale/lumbosacral region of the spinal cord. It is designated as a grade I tumor in the most recent WHO Classification of Tumours of the CNS, although aggressive clinical behavior can be observed, especially in cases arising in an extradural location. Anaplastic transformation in MPE is exceedingly rare with <20 examples reported in the English literature, and consensus on diagnostic features and definitive grading remain to be determined. Here, we present 2 cases of recurrent MPE with anaplastic features, both of which had histology consistent with conventional MPE as well as areas with significant atypia, frequent mitotic figures, elevated Ki-67 proliferation indices (>10%-50%), necrosis, and focal vascular proliferation. Targeted next-generation sequencing panels revealed no definitive pathogenic mutations or fusion proteins in either case. Copy number profiling, methylation profiling, and t-Distributed Stochastic Neighbor Embedding were performed to investigate the molecular characteristics of these tumors. To the best of our knowledge, these are the first reported cases of MPE with anaplastic features with methylation profiling data. In addition, we review the literature and discuss common histologic and molecular findings associated with anaplastic features in MPE.

Recurrent Extradural Myxopapillary Ependymoma With Oligometastatic Spread

Myxopapillary ependymomas are a slow-growing, grade I type glial tumor in the lumbosacral region. More rarely, they can present as extradural, subcutaneous sacrococcygeal, or perisacral masses, and it is under these circumstances that they are more likely to spread. Here, we report the presentation of a sacrococcygeal mass in patient that was initially resected confirming extradural myxopapillary ependymoma. At initial resection, multiple small pulmonary nodules were detected. This mass recurred 2 years later at the resection site with an interval increase in the previously imaged pulmonary nodules. Resection of both the post-sacral mass and largest lung metastasis confirmed recurrent myxopapillary ependymoma with oligometastatic spread. Because these tumors are rare, with extradural presentation being even more infrequent, to this date there are no definitive therapeutic guidelines for initial treatment and continued surveillance. For myxopapillary ependymoma, current standard of care is first-line maximal surgical resection with or without postoperative radiotherapy depending on the extent of disease and extent of resection. However, there remains insufficient evidence on the role of radiotherapy to oligometastatic foci in providing any further survival benefit or extending time to recurrence. Thus, prospective studies assessing the role of upfront treatment of oligometastases with local resection and adjuvant radiotherapy are needed for improved understanding of extradural myxopapillary ependymoma.

Glial Fibrillary Acidic Protein and Ubiquitin C-Terminal Hydrolase-L1 Are Not Specific Biomarkers for Mild CT-Negative Traumatic Brain Injury

Glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase-L1 (UCH-L1) have been studied as potential biomarkers of mild traumatic brain injury (mTBI). We report the levels of GFAP and UCH-L1 in patients with acute orthopedic injuries without central nervous system involvement, and relate them to the type of extracranial injury, head magnetic resonance imaging (MRI) findings, and levels of GFAP and UCH-L1 in patients with CT-negative mTBI. Serum UCH-L1 and GFAP were longitudinally measured from 73 patients with acute orthopedic injury on arrival and on days 1, 2, 3, 7 after admission, and on the follow-up visit 3-10 months after the injury. The injury types were recorded, and 71% patients underwent also head MRI. The results were compared with those found in patients with CT-negative mTBI (n = 93). The levels of GFAP were higher in patients with acute orthopedic trauma than in patients with CT-negative mTBI (p = 0.026) on arrival; however, no differences were found on the following days. The levels of UCH-L1 were not significantly different between these two groups at any measured point of time. Levels of GFAP and UCH-L1 were not able to distinguish patients with CT-negative mTBI from patients with orthopedic trauma. Patients with orthopedic trauma and high levels of UCH-L1 or GFAP values may be falsely diagnosed as having a concomitant mTBI, predisposing them to unwarranted diagnostics and unnecessary brain imaging. This casts a significant doubt on the diagnostic value of GFAP and UCH-L1 in cases with mTBI.

Spinal myxopapillary ependymomas: a retrospective clinical and immunohistochemical study

BACKGROUND

Myxopapillary ependymoma (MPE) is a rare subtype of ependymoma that develops almost exclusively within the spinal cord. Despite its benign biological nature, MPE has a propensity to recur locally or distantly. Although variables influencing the prognosis, such as age, the extent of surgery and radiotherapy, have been widely discussed, no definitive standard has been established. Compared to other spinal tumors, many fewer histological markers have been elucidated to assist the determination of the prognosis.

METHODS

Twenty-seven patients who underwent resection of MPE were enrolled. We determined their demographic features, imaging characteristics, clinical presentations and outcomes, surgical procedures and histological properties by chart review, telephone contact, reviewing of surgical notes, pre-/postoperative imaging and immunohistological staining.

RESULTS

GTR (gross total resection) was achieved in 18 patients (66.7 %) and STR (subtotal resection) in 9 (33.3 %). Although GTR rendered a better disease control rate, the difference was not significant. Pediatric patients suffered from a greater risk of recurrence as well as a shorter period to disease relapse. In the majority of cases, we observed the overexpression of platelet-derived growth factor receptor α (PDGFRα), matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-14 (MMP14). Epidermal growth factor receptor (EGFR) was observed in the tumors of 7 of 23 nonrecurrent patients, but not in any recurrent tumors.

CONCLUSIONS

The results of the present study indicate that the extent of resection and age are major factors related to tumor recurrence. Therefore, gross total resection is recommended whenever possible unless following neurological dysfunction is predictable. Moreover, pediatric patients need considerable attention after surgery, particularly in the early stages. PDGFRα, MMP2 and MMP14 may be new diagnostic and therapeutic targets and EGFR a potential predictor of improved prognosis for MPE.

Spinal Myxopapillary Ependymomas Demonstrate a Warburg Phenotype

PURPOSE

Myxopapillary ependymoma (MPE) is a distinct histologic variant of ependymoma arising commonly in the spinal cord. Despite an overall favorable prognosis, distant metastases, subarachnoid dissemination, and late recurrences have been reported. Currently, the only effective treatment for MPE is gross-total resection. We characterized the genomic and transcriptional landscape of spinal ependymomas in an effort to delineate the genetic basis of this disease and identify new leads for therapy.

EXPERIMENTAL DESIGN

Gene expression profiling was performed on 35 spinal ependymomas, and copy number profiling was done on an overlapping cohort of 46 spinal ependymomas. Functional validation experiments were performed on tumor lysates consisting of assays measuring pyruvate kinase M activity (PKM), hexokinase activity (HK), and lactate production.

RESULTS

At a gene expression level, we demonstrate that spinal grade II and MPE are molecularly and biologically distinct. These are supported by specific copy number alterations occurring in each histologic variant. Pathway analysis revealed that MPE are characterized by increased cellular metabolism, associated with upregulation of HIF1α. These findings were validated by Western blot analysis demonstrating increased protein expression of HIF1α, HK2, PDK1, and phosphorylation of PDHE1A. Functional assays were performed on MPE lysates, which demonstrated decreased PKM activity, increased HK activity, and elevated lactate production.

CONCLUSIONS

Our findings suggest that MPE may be driven by a Warburg metabolic phenotype. The key enzymes promoting the Warburg phenotype: HK2, PKM2, and PDK are targetable by small-molecule inhibitors/activators, and should be considered for evaluation in future clinical trials for MPE.

High plasma-GFAP levels in metastatic myxopapillary ependymoma

Myxopapillary ependymoma (MPE) is a rare tumor of the distal spinal cord. Despite benign histopathology, local recurrences occur in ~30 % of patients and distant metastases have been described in few cases. MPE tumor cells typically express glial fibrillary acidic protein (GFAP), which could be released to the circulation. In this current report, we investigated circulating plasma-GFAP in a series of MPE patients. We analyzed circulating plasma-GFAP using a commercially available ELISA kit in 3 patients with completely resected MPE, 1 patient with locally advanced MPE and 2 patients with pleuropulmonary metastases of MPE. As controls we used blood samples of age and gender-matched healthy volunteers (n = 3), 6 glioblastoma patients with known plasma-GFAP status (positive for 3 and negative for 3 patients) and 3 brain metastases patients with known plasma-GFAP negativity. We found very high concentrations of plasma-GFAP in two MPE patients with pleuropulmonary metastases, while in none of the other MPE patients circulating plasma-GFAP was detectable. Circulating GFAP could be useful as marker for early detection or follow-up of distant metastases in MPE patients.

Circulating biomarkers of CNS tumors: an update

CNS tumors comprise approximately 120 histological subtypes. Advances of surgical resection, radiation and systemic therapy have increased the survival rates of distinct types of CNS tumor patients. There is growing interest in identification of diagnostic, prognostic or predictive blood biomarkers in CNS tumor patients, and emerging studies indicate that certain brain tumors are indeed associated with distinct profiles of circulating factors such as proteins (e.g., glial fibrillary acidic protein), DNA fragments (e.g., containing mutated IDH) or miRNAs (e.g., miRNA-21). However, blood biomarker research in neurooncology is, for the most part, at an exploratory level, and adequately powered and well-designed studies are needed to translate the available interesting but preliminary findings into actual clinical use. In this review, the current knowledge on circulating biomarkers of CNS tumors is briefly summarized.

Spinal cord ependymomas in children and adolescents

BACKGROUND

Spinal cord ependymomas are very rare among children and adolescents. Due to their rarity, our current knowledge of these tumors is based on case reports and few retrospective case series.

METHODS

The present review summarizes the currently available literature on childhood spinal cord ependymomas.

RESULTS

Although overall survival rates are favorable, relapse incidence is high, particularly in myxopapillary ependymomas. Since long-term follow-up data are provided in a limited number of studies only, the true relapse incidence is unknown. Maximal safe radical surgery is the backbone of treatment for children with spinal cord ependymomas, but the impact of adjuvant treatment on progression and survival is still unclear. Presently, the decision to initiate non-surgical treatment depends primarily on the WHO grade of the tumor and the extent of resection. In terms of the known side effects, early radiotherapy should be avoided in children with WHO grade II spinal cord ependymomas irrespective of the extent of resection but is indicated in anaplastic spinal cord ependymomas both after complete and incomplete resection. The high relapse incidence in myxopapillary ependymomas argue for the use of early radiotherapy, but its definitive impact on progression has to be proven in larger series. Close surveillance is important due to the high recurrence rate in all patients with spinal cord ependymomas.

CONCLUSION

Prospective collection of both clinical and molecular data from a greater number of patients with spinal cord ependymomas within an international collaboration is the prerequisite to establish standardized management guidelines for these rare CNS tumors.