Origin of chordoid glioma of the third ventricle

Pediatric CNS tumors and 2021 WHO classification: what do oncologists need from pathologists?

The fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS), published in 2021, established new approaches to both CNS tumor nomenclature and grading, emphasizing the importance of integrated diagnoses and layered reports. This edition increased the role of molecular diagnostics in CNS tumor classification while still relying on other established approaches such as histology and immunohistochemistry. Moreover, it introduced new tumor types and subtypes based on novel diagnostic technologies such as DNA methylome profiling. Over the past decade, molecular techniques identified numerous key genetic alterations in CSN tumors, with important implications regarding the understanding of pathogenesis but also for prognosis and the development and application of effective molecularly targeted therapies. This review summarizes the major changes in the 2021 fifth edition classification of pediatric CNS tumors, highlighting for each entity the molecular alterations and other information that are relevant for diagnostic, prognostic, or therapeutic purposes and that patients' and oncologists' need from a pathology report.

Endoscope-assisted Trans-lamina Terminalis Resection of Chordoid Glioma at the Third Ventricle: A Case Report

As per the 2021 World Health Organization (WHO) Classification of Tumors of the Central Nervous System, chordoid glioma (CG) is defined as a slow-growing glial neoplasm categorized as grade II tumor. This tumor is primarily located in the anterior part of the third ventricle, often adheres to important surrounding structures, and is hemorrhagic in nature. Therefore, dissecting this tumor is extremely difficult. In this study, we present the case of a 44-year-old man who initially complained of mild headache and was diagnosed with a homogeneous gadolinium-enhanced lesion in the third ventricle via magnetic resonance imaging. The pathological diagnosis based on his biopsy at the previous hospital was CG. The patient demonstrated no neurological deficit at that time, but the tumor had gradually grown, hydrocephalus appeared 2 years after the tumor was detected, and the patient developed short memory disorder and daytime sleepiness. We resected the tumor via the anterior interhemispheric trans-lamina terminalis approach using a microscope and an endoscope. The residual tumor at the blind spot of the microscopic view was resected under an angled rigid endoscopic view using dedicated tools for transsphenoidal surgery. The tumor was grossly resected, and the histopathological diagnosis was CG. Postoperative neurological findings included slight memory disorder and hypothalamic adrenal dysfunction. No tumor recurrence was reported 3 years post resection. The endoscope-assisted anterior interhemispheric trans-lamina terminalis approach was determined useful for CG resection with minimal surgical complications and without tumor recurrence.

Pediatric diencephalic tumors: a constellation of entities and management modalities

The diencephalon is a complex midline structure consisting of the hypothalamus, neurohypophysis, subthalamus, thalamus, epithalamus, and pineal body. Tumors arising from each of these diencephalic components differ significantly in terms of biology and prognosis. The aim of this comprehensive review is to describe the epidemiology, clinical symptoms, imaging, histology, and molecular markers in the context of the 2021 WHO classification of central nervous system neoplasms. We will also discuss the current management of each of these tumors.

[Chordoid gliomas of the third ventricle]

BACKGROUND

Chordoid glioma is a rare slow-growing tumor of the central nervous system. Available world experience includes no more than 200 cases (lesion of the third ventricle in absolute majority of cases). Recognition and treatment of chordoid glioma are currently difficult problems due to small incidence of this disease.

OBJECTIVE

To describe clinical manifestations and surgical treatment of chordoid glioma of the third ventricle considering literature data and own experience.

MATERIAL AND METHODS

There were 12 patients (6 men and 6 women) with chordoid glioma between 2004 and 2023 (10 patients with lesion of the third ventricle, 1 - lateral ventricle, 1 - pineal region). Only patients with tumors of the third ventricle were analyzed.

RESULTS

Total and subtotal resection was performed in 1 and 3 cases, respectively. Five patients underwent partial resection, 1 patient underwent biopsy. The follow-up data were available in 7 out of 10 patients (mean 25 months). Radiotherapy was performed in 4 patients (continued tumor growth in 2 cases). One patient died.

CONCLUSION

Chordoid glioma is a benign tumor predominantly localized in the third ventricle. Preoperative MRI and CT in some cases make it possible to suspect chordoid glioma and differentiate this tumor from craniopharyngioma, meningioma and pituitary adenoma by such signs as isointense signal in T1WI, hyper- or isointense signal in T2WI, homogeneous contrast enhancement and edema of basal ganglia in T2 FLAIR images. The only effective treatment for chordoid glioma is surgery. Total resection is often impossible or extremely dangerous due to location of tumor, large size and invasion of the third ventricle. Postoperative mental disorders and diabetes insipidus, including severe hypernatremia, are common that requires mandatory monitoring of water and electrolyte balance.

Magnetic resonance imaging of a third ventricular chordoid glioma

Chordoid gliomas are uncommon neoplasms located within the anterior portion of the third ventricle. In this article, we aimed to describe the clinical presentation, magnetic resonance imaging characteristics, histological findings, and surgical treatment applied to a case of chordoid glioma. Chordoid gliomas are typically observed as solid masses within the anterior segment of the third ventricle, characterized by homogenous and vivid enhancement. Despite being classified as a low-grade neoplasm, the outcome of choroid glioma is often uncertain.

Occurrence of Chordoid Glioma With Sodium Ion Metabolism Disorder 5 Years After Meningioma Surgery and Whole-Exome Sequencing: A Case Report and Literature Review

Chordoid glioma (CG), a rare slow-growing brain tumor, mainly occurs in the region of the third ventricle. Although its degree of malignancy is relatively low, its clinical prognosis is poor due to obscure clinical manifestations and the particular growing position. Currently, gross total resection is the best available method for treatment of CG. However, the tumor is located in the deep structure of the brain and close to neurovascular structure so it is difficult to remove completely. This study reported a case of CG of the third ventricle 5 years after surgery of right frontal parietal fibrous meningioma, accompanied with peri and post-operative sodium ion metabolism disorder. Whole-exome sequencing (WES) revealed 25 gene mutations shared by meningioma and CG. In addition, the PRKCA ^D463H CG marker gene mutation also existed in this patient. We reviewed the latest literature on this rare brain tumor, summarized its clinical manifestations, imaging and pathological characteristics, and discussed the mechanism related to its occurrence and the reasons for sodium ion disorder.

Chordoid Glioma With Dot-Like Immunoreactivity for Synaptophysin

Chordoid gliomas arise near the third ventricle and commonly present around 40 years of age. These rare tumors are non-invasive and often present with headaches and visual disturbances. Contrast enhancement on MRI is typical for these tumors and immunohistochemical (IHC) staining is positive for glial fibrillary acidic protein (GFAP). Surgical resection is the treatment of choice. We present this case of chordoid glioma because of its unique characteristics. The tumor lacked contrast enhancement on MRI and demonstrated juxtanuclear dot-like immunoreactivity for synaptophysin which is a feature not previously reported in the literature. It is important for pathologists and radiologists to be on the lookout for atypical presentations of these rare tumors.

One of a kind-chordoid glioma in the fourth ventricle: a case report and literature review

Chordoid glioma (CG) is a rare brain tumor that is known for its characteristic location in the third ventricle. A wide spectrum of radiological presentations has been described, with few common features among them. Its radiological diagnosis is mainly suggested by location. However, several cases of CG with atypical locations have been described, illustrating that CG is not limited to the third ventricle, and should be considered in the list of radiological differential diagnosis for intraventricular masses. We present here a case of CG that was found in the fourth ventricle.

Intracranial chordoid glioma: A clinical, radiological and pathological study of 14 cases

BACKGROUND

Chordoid gliomas (CGs) are rare neuroepithelial tumors, which commonly arise from the anterior part of the third ventricle. Most studies on CGs included only one or two cases. To better understand the disease, we report 14 patients with pathologically confirmed CGs.

METHOD

The clinical characteristics, including radiological and histological examination, operative records, and prognoses were analyzed and reviewed.

RESULT

The case series included six male and eight female patients with an average age of 44.4 years. The most common preoperative symptom was headache (64.3%) and visual deterioration (57.1%). Radiological results showed that the third ventricle (12/14) was the most common site of the brain involved, and the lesions presented with solid (n = 9, 64.3%) or cystic-solid (n = 5, 35.7%) appearance. All patients were misdiagnosed as non-CG tumors. The operation approach was mainly determined by tumor location, thus trans-callosal approach (9/14) and trans-laminar terminalis approach were commonly used. Gross total resection (GTR) was achieved in all cases and none of them received any adjuvant therapy postoperatively. The most frequent postoperative complications were diabetes insipidus, electrolyte disturbance, hypopituitarism, cognitive dysfunction, and obstructive hydrocephalus. During an average follow-up period of 40.1 months, 2 cases (14.3%) were died of refractory hypopituitarism and pulmonary embolism, respectively. The preoperative symptoms and postoperative complications were all significantly improved in other 12 patients, and MRI showed no tumor recurrence.

CONCLUSION

According to our experience, we recommend GTR as the primary goal, which is associated with improved rates of tumor control and without increasing rates of postoperative complications.

Chordoid Glioma of the Third Ventricle: A Case Report and a Treatment Strategy to This Rare Tumor

Chordoid glioma (CG) of the third ventricle is a rare type of brain tumor. Here, we present a case, review of the literature and proposed a treatment strategy for this rare tumor. Here, A 33-years-old woman presented with the menstrual disorder and progressive obesity. Magnetic resonance imaging showed a large irregularly circular tumor in the third ventricle. The tumor was subtotally resected by microsurgery via the right modified port approach. Immunohistochemical staining was positive for glial fibrillary acidic protein (GFAP), Vimentin and transcription termination factor-1 (TTF-1), and the Ki-67 proliferation index was low (5%), which indicating CG. Residual tumor decreased after treated by Gamma Knife radiosurgery (GKRS) with a dose of 15 Gy. During 30 months of follow-up, the tumor did not recur, and the patient suffered no complications. The diagnosis of CG requires a combination of clinical presentation, neuroimaging, and pathology. The ideal therapy is gross total resection (GTR) of the tumor. However, GTR is usually difficult and carries a high risk of postoperative complications because of the tumor location. This case indicates that planed subtotal resection followed by GKRS with a proper marginal dose could be a good treatment strategy for CG.

Chordoid glioma of the third ventricle: a patient presenting with SIADH and a review of this rare tumor

INTRODUCTION

Chordoid glioma of the third ventricle is a rare and recently described tumor characterized by a unique histomorphology and exclusive association with the suprasellar/third ventricular compartment. Its clinical, radiological and histological features may vary. Despite the fact that chordoid glioma is a low-grade tumor, its prognosis has been relatively poor because of its insidious presentation and the difficulty in obtaining complete surgical resection.

MATERIALS AND METHODS

Here, we report on a new case of chordoid glioma occurring in a 48-year-old woman, presented with hyponatremia, and on the initial work-up with a diagnosis of hyponatremia due at least in part to SIADH. We review the current literature on this rare pathology, discuss the radiological and histopathologic findings, and discuss the optimal management of chordoid glioma in general.

CONCLUSION

Based on this new case and the previous literature reports, we suggest that chordoid glioma should be included in the differential diagnosis of uncommon masses of the third ventricle, especially in middle-aged women, and we emphasize current management guidelines.

Chordoid Glioma of Third Ventricle With an Epidermoid Cyst: Coexistence or Common Histogenesis?

Chordoid glioma (CG) is a World Health Organization classified grade II tumor located exclusively in the region of anterior third ventricle. Association of CG with other lesions is extremely rare. We report a case of CG in a 45-year-old male coexisting with an epidermoid cyst in the third ventricle. Ultrastructural examination of the CG revealed microvilli, junctional complexes, and intermediate filaments within the cytoplasm suggesting origin from specialized ependyma. The association of the 2 lesions appears coincidental as convincing evidence for a common histogenesis was not found.

The clinicopathological features of pituicytoma and the differential diagnosis of sellar glioma

Pituicytoma is rare and difficult to diagnose. This study explored the clinicopathological features, immunophenotype and differential diagnosis of pituicytoma. We compared 11 cases of pituicytoma and 26 cases of sellar glioma (16 pilocytic astrocytomas, four diffuse astrocytomas, three pilomyxoid astrocytomas, and three third ventricle chordoid gliomas). The 11 pituicytoma cases involved six men and five women (age: 33-65 years). Three of the 11 patients experienced recurrence due to a residual tumor, and one patient underwent three surgeries during a 6-month period. Imaging findings revealed tumors were in the intrasellar region (four cases), suprasellar region (four cases) and intra-suprasellar regions (three cases). The tumor diameters were 1.3-3.8 cm, and the preoperative diagnoses were pituitary adenoma, craniopharyngioma and meningioma. The tumors were solid and contained spindle or slightly chubby cells that were densely arranged with visible cleft-like or expanded sinusoid structures. The cells had vague boundaries, circular nuclei, fine chromatin, and a small nucleolus. Immunohistochemical staining of the pituicytomas revealed positive expression of thyroid transcription factor-1 (TTF-1) and S-100 protein (S-100), positive focal expression of glial GFAP;(five of 11 cases), and negative oligodendrocyte transcription factor 2 (Olig2), CD34 and neurofilament expression. The Ki67 index was 6% in one case and 1-2% in the other cases. Unlike pituicytoma, most sellar glioma cases exhibited GFAP and Olig2 expression, and negative TTF-1 expression. Third ventricle chordoid gliomas expressed TTF-1, GFAP and CD34, and were negative for Olig2. Our results indicate that pituicytoma typically involves dense arrangements of spindle or slightly chubby cells. The morphology is occasionally atypical, with ependymoma-like or meningioma-like structures, and occasionally exhibits pilomyxoid degeneration. Abundant sinusoids are characteristic of hemorrhagic tumors. The dense spindle cell arrangement is a relatively specific morphology, and staining for GFAP, TTF-1, Olig2 and CD4 may help differentiate pituicytoma from sellar glioma.

Prognostic factors for recurrence and complications in the surgical management of primary chordoid gliomas: A systematic review of literature

OBJECTIVE

Chordoid gliomas (CG) are rare neoplasms which frequently arise within the third ventricle. Surgery remains the mainstay treatment for CG. The present study comprehensively reviews all reported cases of CG within the literature in order to identify risk factors for surgical complications and tumor recurrence.

METHODS

A comprehensive search on MEDLINE (OVID and PubMed), Scopus, Embase, and Web of Science was conducted following PRISMA guidelines to identify all reported cases of CG.

RESULTS

A total of 81 patients met the study criteria which comprised of 33 males and 48 females. Median age at diagnosis was 48 years with a range from 5 to 72 years, and mean tumor size was 3.1cm. Biopsy, subtotal resection (STR), and gross total resection (GTR) were achieved in 8, 34, and 33 patients, respectively, with six cases not reporting extent of resection (EOR). Thirteen patients underwent adjuvant radiotherapy. Postoperative complications were noted in 30 cases (37%), with new onset diabetes insipidus being the most common. Postoperative morbidity was not associated with age, tumor size, or extent of resection. A trans-lamina terminalis approach demonstrated a strong trend towards decreased overall rates of postoperative morbidity compared to other approaches (p=0.051). GTR was associated with improved progression-free survival (PFS; p=0.028), while adjuvant radiotherapy, age, tumor size and proliferative index were not predictive of patient outcomes.

CONCLUSION

GTR should be the primary goal for the management of CG, as it is associated with improved rates of tumor control without an increased rate of postoperative complications. Surgical approach was a stronger predictor of complication rates than extent of resection. Morbidity remains high, and future studies to further elaborate on factors predictive of postoperative complications are critical.

Chordoid glioma: a rare radiologically, histologically, and clinically mystifying lesion

Chordoid glioma (CG) is a rare central nervous system neoplasm (WHO grade II) of uncertain origin whose typical localization is in the anterior part of the third ventricle. Its clinical, radiological, and histological features may vary and furthermore mimic other kind of benign lesions usually associated with a better outcome. We report a case of a 43-year-old female who underwent gross total removal of a lesion of the third ventricle causing hydrocephalus. The imaging studies and the intraoperative examination led at first to a hypothesis of meningioma. Early surgical and neurological outcomes were good. The patient underwent multiple complications related to hypothalamic dysfunctions and thrombohemorragic issues and eventually died because of systemic infections. Definitive examination was of chordoid glioma of the third ventricle. Reviewing literature, we evaluated possible pitfalls in radiological and histological diagnosis as well as in surgical and medical treatment of CGs. Despite their benign presentation, a high incidence of multiple possible severe complications is reported. Early alertness and combined treatment strategies could improve overall CGs treatment strategies.

Suprasellar chordoid neoplasm with expression of thyroid transcription factor 1: evidence that chordoid glioma of the third ventricle and pituicytoma may form part of a spectrum of lineage-related tumors of the basal forebrain

Chordoid glioma of the third ventricle is a rare neuroepithelial tumor characterized by a unique histomorphology and exclusive association with the suprasellar/third ventricular compartment. Variously interpreted as either astrocytic- or ependymal-like, and speculatively ascribed to the lamina terminalis/subcommissural organ, its histogenesis remains, nevertheless, unsettled. Here, we report on a suprasellar chordoid glioma occurring in a 52-year-old man. Although displaying otherwise typical morphological features, the tumor was notable for expression of thyroid transcription factor 1, a marker of tumors of pituicytic origin in the context of the sellar region. We furthermore found overlapping immunoprofiles of this example of chordoid glioma and pituicytic tumors (pituicytoma and spindle cell oncocytoma), respectively. Specifically, phosphorylated ribosomal protein S6, a marker of mTOR pathway activation, was expressed in both groups. Based on these findings, we suggest that chordoid glioma and pituicytic tumors may form part of a spectrum of lineage-related neoplasms of the basal forebrain.

Anatomical, molecular and pathological consideration of the circumventricular organs

BACKGROUND AND PURPOSE

Circumventricular organs (CVOs) are a diverse group of specialised structures characterized by peculiar vascular and position around the third and fourth ventricles of the brain. In humans, these organs are present during the fetal period and some become vestigial after birth. Some, such as the pineal gland (PG), subcommissural organ (SCO) and organum vasculosum of the lamina terminalis (OVLT), which are located around the third ventricle, might be the site of origin of periventricular tumours. In contrast to humans, CVOs are present in the adult rat and can be dissected by laser capture microdissection (LCM).

METHODS

In this study, we used LCM and microarrays to analyse the transcriptomes of three CVOs, the SCO, the subfornical organ (SFO) and the PG and the third ventricle ependyma of the adult rat, in order to better characterise these organs at the molecular level. Furthermore, an immunohistochemical study of Claudin-3 (CLDN3), a membrane protein involved in forming cellular tight junctions, was performed at the level of the SCO.

RESULTS

This study highlighted some potentially new or already described specific markers of these structures as Erbb2 and Col11a1 in ependyma, Epcam and CLDN3 in the SCO, Ren1 and Slc22a3 in the SFO and Tph, Anat and Asmt in the PG. Moreover, we found that CLDN3 expression was restricted to the apical pole of ependymocytes in the SCO.

From the radiologic pathology archives: intraventricular neoplasms: radiologic-pathologic correlation

A variety of neoplasms may arise in the ventricular system. Intraventricular neoplasms may be discovered as an incidental finding at cross-sectional imaging or may manifest with varied symptoms depending on their location, including symptoms of increased intracranial pressure. These lesions may arise from various ventricular structures, including the ependymal lining (eg, ependymoma), subependymal layer (eg, subependymoma), or choroid plexus (eg, choroid plexus neoplasms), or they may have a cell of origin that has yet to be determined (eg, chordoid glioma). Other neoplasms involving the ventricular system include central neurocytoma, subependymal giant cell tumor, meningioma, rosette-forming glioneuronal tumor, and metastases. The differential diagnosis for intraventricular neoplasms can be broad, and many of them have similar patterns of signal intensity and contrast enhancement at imaging. However, the location of the lesion in the ventricular system-along with knowledge of the patient's age, gender, and underlying conditions-will help narrow the differential diagnosis.

Molecular characterization of circumventricular organs and third ventricle ependyma in the rat: potential markers for periventricular tumors

Circumventricular organs (CVOs) are specialized ventricular structures around the third and fourth ventricles of the brain. In humans, these structures are present during the fetal period and some become vestigial after birth. Some of these organs, such as the pineal gland (PG), subcommissural organ (SCO), and organum vasculosum of the lamina terminalis, might be the sites of origin of periventricular tumors, notably pineal parenchymal tumors, papillary tumor of the pineal region and chordoid glioma. In contrast to the situation in humans, CVOs are present in the adult rat and can be dissected by laser capture microdissection (LCM). In this study, we used LCM and microarrays to analyze the transcriptomes of three CVOs, the SCO, the subfornical organ (SFO), and the PG and the third ventricle ependyma in the adult rat, in order to better characterize these organs at the molecular level. Several genes were expressed only, or mainly, in one of these structures, for example, Erbb2 and Col11a1 in the ependyma, Epcam and Claudin-3 (CLDN3) in the SCO, Ren1 and Slc22a3 in the SFO and Tph, Aanat and Asmt in the PG. The expression of these genes in periventricular tumors should be examined as evidence for a possible origin from the CVOs. Furthermore, we performed an immunohistochemical study of CLDN3, a membrane protein involved in forming cellular tight junctions and found that CLDN3 expression was restricted to the apical pole of ependymocytes in the SCO. This microarray study provides new evidence regarding the possible origin of some rare periventricular tumors.

Chordoid glioma: ten years of a low-grade tumor with high morbidity

We report two new cases of chordoid glioma of the third ventricle and review all previously published cases of this rare tumor with regard to presentation, optimum management, and outcome. Two new cases are reported with the radiological and histopathologic findings. We searched and cross-referenced PubMed and published reports of this tumor to retrieve an additional 51 cases of this tumor, which were then analyzed according to a proforma. Chordoid glioma has consistent radiological features, although some atypical elements including a cystic component are well described. The insidious presentation and morbidity of attempted surgical resection combine to give high overall morbidity. There is a high incidence of postoperative thromboembolic disturbance. Adjuvant radiosurgery has a promising role. The morbidity of this condition is likely to remain high but may be minimized by a less aggressive surgical approach together with surveillance and early use of radiosurgery.

Chordoid glioma : a case report of unusual location and neuroradiological characteristics

Since the World Health Organization (WHO) classification for central nervous system neoplasms was declared in 2000, chordoid glioma of the third ventricle has been noted as a newly recognized tumor for central nervous system neoplasms. Although there is not enough universal experience to know the nature of this tumor due to its rarity, the origin of chordoid glioma was guardedly proposed to be the ependymal cells of the third ventricle. Such an idea has been primarily based on the specific location of the tumor, that is, third ventricle, suprasellae, and hypothalamus. However, we report a rare case of histologically confirmed chordoid glioma located in the left thalamus, not attached to any of the midline structures having unusual neuroradiological characteristics.

Glioma diagnosis: immunohistochemistry and beyond

Clinicians and pathologists have been inundated by published reports of new and potentially interesting diagnostic, prognostic, and putative predictive "markers" whose expression (or loss) holds great promise for more enlightened diagnoses and ultimately better patient care. Although an understanding of therapeutically (and possibly diagnostically) relevant pathways of glioblastoma may be at hand, significant challenges remain. Many immunohistochemical and genetic tests have proven to be useful in the stratification of clinical trials, whereas the utility of many others for the day-to-day practice of pathology awaits further study and validation. The importance of critical literature review and careful consideration of practical issues such as test standardization, compliance, cost-effectiveness, and availability must all be considered before implementing any new diagnostic test. This review will focus on the role of immunohistochemistry in the routine diagnosis of astrocytic and oligodendrocytic tumors and in assisting with the diagnosis of some less common gliomas that have ependymal-like features. It will conclude with a summary of molecular and genetic studies, which not only hold great promise for improved diagnosis, but also reveal prognostic information on disease outcome and predict response to treatment or provide biologic targets for novel therapies.

Chordoid glioma of the third ventricle

BACKGROUND

Chordoid glioma is a rare tumour (World Health Organisation grade II) originating from the third ventricle with both glial and chordoid features. It was first described by Brat in 1998. Since there is no detailed information available on the outcome after surgery and adjuvant treatment, we reviewed the literature.

METHODS

A literature search through PUBMED revealed 50 cases of chordoid glioma. Most reports were found in pathology journals. Information on the postoperative course was sometimes very limited. We reviewed the available literature and studied in detail the presenting symptoms, mortality and postoperative complications in relation to the extent of resective surgery, as well as the importance of adjuvant treatment.

CONCLUSIONS

Mortality in the immediate postoperative period is 32% and is higher after gross total resection as compared to subtotal resection. Non-fatal postoperative complications are hypothalamic disorders and mental alterations. Gross total resection is the treatment of choice since no recurrence has been reported after macroscopically complete resection, but this is often difficult because of the location and adherence to the hypothalamus. The role of postoperative radiotherapy is uncertain. There is some indication that radiosurgery with or without conventional irradiation is superior to conventional radiation alone. Planned subtotal resection followed by stereotactic radiosurgery can be a safe and effective alternative in a patient in whom gross total resection is considered to be too risky. There is no report on the use of chemotherapy in the treatment of chordoid gliomas. More information about the optimal treatment strategy is needed, and more reports are also needed.

Chordoid glioma: a case report and molecular characterization of five cases

Chordoid gliomas are rare, slow-growing neoplasms of the anterior third ventricle. We reported a case of chordoid glioma in a 41-year-old man with obstructive hydrocephalus. Histologically, the tumor consisted of polygonal epithelioid cells admixed with elongated cells in a myxoid stroma. A prominent lymphoplasmacytic infiltrate was present. The tumor cells expressed glial fibrillary acidic protein (GFAP), epithelial membrane antigen (EMA), vimentin, CD31, CD34, epidermal growth factor receptor (EGFR) and S100 but were negative for pankeratin and E-cadherin. The percentage of Ki67 positive cells was approximately 3%. Weak p53 immunoreactivity was seen in less than 10% of the cells. Array comparative genomic hybridization performed on this case, as well as on four other archived cases, showed losses at several loci. Fluorescence in situ hybridization (FISH) confirmed consistent genetic alterations at 9p21 and 11q13. These are the fifth through ninth reported cases of chordoid gliomas with molecular characterization suggesting a distinct genetic origin from other gliomas.

Chordoid glioma of the third ventricle attached to the optic chiasm. Successful removal through a trans-lamina terminalis approach

Chordoid glioma of the third ventricle constitutes a rare, very recently recognized histological entity. Most reports of this neoplasm, focused on its distinct histological features, have hypothesized about a probable origin of the lesion at the third ventricle floor and/or the lamina terminalis. We report on a new case, presenting neuroradiological and intraoperative pictorial evidences of the tumoral attachment, limited to the chiasm-lamina terminalis junction. A 53-year-old woman debuted with acute symptoms of obstructive hydrocephalus, visual disturbances and confusion. MRI investigation showed a large solid-cystic third ventricle mass bulging through the lamina terminalis and ventricular floor. After placing a ventriculoperitoneal shunt, the tumor was completely removed through a trans-lamina terminalis approach. A tight tumoral attachment to the junction of the posterior chiasm to the lamina terminalis was identified and dissected. No other adhesions to the third ventricle boundaries were found. A chordoid glioma was diagnosed on histological examination. One year after the surgical procedure the patient does not present new neurological deficits, and there are no signs of tumoral regrowth on the follow-up postoperative MRI. Chordoid glioma should be included in the differential diagnosis of third ventricle tumors. Preoperative neuroradiological suspicion of this lesion should alert the neurosurgeon about the presence of a tight tumoral adherence at the level of the chiasm-lamina terminalis junction. The trans-lamina terminalis approach provides a suitable route for an early control of this attachment under direct vision, allowing a safe dissection of the mass from the third ventricle.

Chordoid glioma of the third ventricle: a report of two cases, one with ultrastructural findings

Chordoid glioma, which generally occurs in adults, is a rare CNS tumor arising in the anterior part of the third ventricle. We report two cases of chordoid glioma of the third ventricle in a 42-year-old woman and a 51-year-old man, respectively. Both tumors showed essentially the same histological and immunohistochemical features; the tumors were composed of cords and nests of epithelioid, GFAP-immunoreactive cells in a mucinous stroma with lymphoplasmacytic infiltrates at the tumor periphery. Ultrastructural examination in one case revealed that the tumor cells were characterized by the presence of hemidesmosomes and associated focal basal lamina formation, intermediate junctions, microvilli and cilia, and intercellular microrosettes with microvilli. Of interest was that small blood vessels with fenestrated endothelial cells were present in the stroma. In the brain, the presence of fenestrated endothelial cells is a feature of the circumventricular organs (except the subcommissural organ), among which the organum vasculosum of the lamina terminalis is located in the anterior part of the third ventricular floor that is lined by specialized ependymal cells known as tanycytes. These findings further strengthen the hypothesis that chordoid glioma may represent a peculiar clinicopathological subtype of ependymoma (chordoid ependymoma) originating from the lamina terminalis area.

Chordoid glioma with calcification and neurofilament expression: case report and review of the literature

BACKGROUND

Chordoid glioma of the third ventricle is a rare type of brain tumor that was recently categorized as a novel tumor entity. Despite low-grade histologic features, the clinical outcome in reported cases was poor.

CASE DESCRIPTION

A 61-year-old woman presented to our institution with a history of syncope. On presentation, she was alert and oriented, and her systemic examination was unremarkable. Computed tomographic scan showed a well-circumscribed, slightly hyperdense mass with calcification and a cystic component in the anterior part of the third ventricle. The mass was homogenously enhancing after the intravenous administration of contrast material, and its maximum diameter was 3.5 cm. The preoperative diagnosis was craniopharyngioma. Because the tumor seemed to invade the hypothalamus bilaterally, the operative plan was to reduce the tumor volume, followed by radiosurgery. The patient underwent partial removal of the tumor via a bifrontal basal interhemispheric approach. The histologic and immunohistochemical findings indicated CG. Surprisingly, tumor cells showed NFP expression. The residual tumor was treated by GKRS and showed no regrowth at 1-year follow-up.

CONCLUSIONS

Chordoid glioma is considered a glial neoplasm with distinct morphological and clinicopathologic features, but there may also be other unknown characteristics because of its rarity. To the best of our knowledge, this is the second reported case of CG with calcification and, at the same time, the second case with NFP expression in the English literature. Calcification and expression of NFP should not exclude CG in the differential diagnosis of a third ventricular tumor. The authors also suggest that the combination of microsurgery and GKRS is a safe and effective treatment strategy for CG.

Papillary tumor of the pineal region and spindle cell oncocytoma of the pituitary: new tumor entities in the 2007 WHO Classification

We have reviewed the features of two recently described intracranial tumors, which have been formally recognized as distinct entities by the 2007 WHO Classification of Brain Tumours: Papillary tumor of the pineal region and spindle cell oncocytoma of the pituitary gland. Their salient clinicopathological features, differential diagnosis, histogenetic hypothesis and outcome are discussed.