Chordoid glioma of the third ventricle: confirmatory report of a new entity

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 of the third ventricle: four cases including one case with papillary features

Chordoid glioma is a rare, slowly growing tumor of the CNS, which is always located in the third ventricle of adults. Chordoid glioma has classic histological features consisting of clusters and cords of epithelioid tumor cells embedded within a mucinous stroma with rich lymphoplasmacytic infiltrate. The important distinctive immunohistochemical feature of this neoplasm is strong and diffuse reactivity for GFAP. Here, we report four cases of chordoid glioma that occupied the anterior portion of the third ventricle or suprasellar region. These four cases were all adult females with almost typical clinical, radiological, histologic and immunohistochemical characteristics of chordoid glioma. However, in one case there was an unusual histologic finding with regard to the papillary region. In this region, elongated tumor cells were observed radiating toward a central vessel to form characteristic papillary structures. Immunohistochemically, three cases showed strong reactivity for GFAP, and one exhibited weak reactivity. All cases were focally positive for epithelial membrane antigen, CD34 and D2-40, but negative for neurofilament protein (NFP). Several ultrastructural investigations have supported the ependymal origin of chordoid glioma. In some cases of immunoreactivity for NFP, some authors have supposed that chordoid glioma originates from a multipotential stem cell with glial and neuronal cell differentiation. With regard to the present four cases with immunoreactivity for D2-40 (an ependymal marker) and CD34 (undifferentiated neural precursors) and based on previously published data, we considered that the majority of chordoid gliomas had an ependymal origin, and that a small minority might have originated from a multipotential stem cell having ependymal and neuronal cell differentiation.

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.

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.

Chordoid glioma of the third ventricle: immunohistochemical and molecular genetic characterization of a novel tumor entity

Chordoid glioma of the third ventricle was recently reported as a novel tumor entity of the central nervous system with characteristic clinical and histopathological features (Brat et al., J Neuropathol Exp Neurol 57: 283-290, 1998). Here, we report on a histopathological, immunohistochemical and molecular genetic analysis of five cases of this rare neoplasm. All tumors were immunohistochemically investigated for the expression of various differentiation antigens, the proliferation marker Ki-67, and a panel of selected proto-oncogene and tumor suppressor gene products. These studies revealed a strong expression of GFAP, vimentin, and CD34. In addition, most tumors contained small fractions of neoplastic cells immunoreactive for epithelial membrane antigen, S-100 protein, or cytokeratins. The percentage of Ki-67 positive cells was generally low (<5%). All tumors showed immunoreactivity for the epidermal growth factor receptor and schwannomin/merlin. There was no nuclear accumulation of the p53, p21 (Waf-1) and Mdm2 proteins. To examine genomic alterations associated with the development of chordoid gliomas, we screened 4 tumors by comparative genomic hybridization (CGH) analysis. No chromosomal imbalances were detected. More focussed molecular genetic analyses revealed neither aberrations of the TP53 and CDKN2A tumor suppressor genes nor amplification of the EGFR, CDK4, and MDM2 proto-oncogenes. Our data strongly support the hypothesis that chordoid glioma of the third ventricle constitutes a novel tumor entity characterized by distinct morphological and immunohistochemical features, as well as a lack of chromosomal and genetic alterations commonly found in other types of gliomas or in meningiomas.

Third Ventricular Chordoid Glioma With Unusual Aggressive Behavior-Case Report-

A 50-year-old woman presented with a rare chordoid glioma manifesting as an approximately 4-year history of decreased cognitive function and recent decreased visual acuity. Magnetic resonance imaging showed a 4.5 x 3.5 cm multilobulated strongly enhanced mass in the suprasellar cistern and third ventricle associated with hydrocephalus. The tumor was subtotally removed via a transcallosal approach. Histological examination showed chordoid glioma. Two months later, ventriculoperitoneal shunting was performed for hydrocephalus. The tumor and hydrocephalus recurred after 3 months. She died after 4 months because of deepened mentality and combined pneumonia. This very short duration before recurrence suggests that neuroimaging follow up may be necessary in patients with subtotally removed choroid glioma.

Third ventricular chordoid glioma: clinicopathological study of two cases with evidence for a poor clinical outcome despite low grade histological features

Chordoid glioma of the third ventricle is a rare glial tumour whose precise histogenesis remains uncertain. We describe two cases that presented recently to our department and review the background literature. The neoplasm tends to occur in women and its clinical presentation is variable, resulting from acute hydrocephalus or impingement upon local structures. However, the radiological appearance is distinct, with an ovoid shape, hyperdensity and uniform contrast enhancement on computerized tomography and magnetic resonance imaging. Intraoperative smear diagnosis is difficult because of the lack of specific features, although the presence of metachromatic extracellular mucin may be useful. The characteristic histological appearance is that of cords and clusters of cohesive, oval-to-polygonal epithelioid cells with abundant eosinophilic cytoplasm and a mucinous background. There is often a mixed chronic inflammatory infiltrate with lymphocytes and plasma cells with Russell bodies. The main differentials for histological diagnosis include chordoid meningiomas, pilocytic astrocytomas and ependymomas. An immunohistochemical panel including antibodies to glial fibrillary acidic protein, CD 34, epithelial membrane antigen, pan cytokeratin, S100 and vimentin can be used to distinguish between these possibilities. Ultrastructurally the tumour cells have basal lamina and microvilli, reminiscent of ependymomas. The clinical outcome in our cases was poor because of the location of the lesion and its close relation to the hypothalamus. Limited follow-up after surgery with or without radiotherapy suggests that as-full-as-possible resection favours a better outcome, although surgery in this area carries significant operative risks.

Newly defined central nervous system neoplasms

In recent years, numerous new entities or variants of recognized central nervous system tumors have been described in the literature, and the morphologic spectrum of these neoplasms is delineated incompletely. The accurate diagnosis and classification of these lesions is important to ensure that patients receive adequate therapy and prognostic information. The clinicopathologic features and differential diagnosis of 4 new entities, including the chordoid glioma of the third ventricle, cerebellar liponeurocytoma, atypical teratoid/rhabdoid tumor, and papillary glioneuronal tumor, are discussed in this review.

Chordoid glioma: clinicopathologic profile and differential diagnosis of an uncommon tumor

Chordoid glioma is an uncommon low-grade brain neoplasm arising in the third ventricular region, predominantly in middle-aged women. It characteristically shows chordoma-like histologic features and glial fibrillary acidic protein immunoreactivity. We present a case of chordoid glioma in a previously healthy 56-year-old woman admitted to our hospital because of a cranial trauma subsequent to an incidental fall. Radiologic examinations revealed a well-demarcated, partially cystic, enhancing mass at the level of the lamina terminalis. The lesion was surgically removed. The patient remained alive and well 8 months after the surgery. Histologically, the tumor consisted of clusters and cords of epithelioid cells embedded in a mucinous matrix. Lymphoplasmacytic infiltrates and Russell bodies were prominent. Immunohistochemically, the tumor cells were positive for glial fibrillary acidic protein, neurofilaments, and neuron-specific enolase, suggesting a divergent neuronal and glial differentiation. The Ki-67 index was low. The clinicopathologic profile and the differential diagnosis of this tumor are discussed.

Suprasellar chordoid glioma combined with Rathke's cleft cyst

Chordoid glioma has been recently described as a slow-growing neoplasm with chordoid appearance, occurring exclusively in the regions of the third ventricle and hypothalamus of middle-aged women. We experienced a case of a 48-year-old woman with a suprasellar tumor composed of chordoid glioma and Rathke's cleft cyst, which was confirmed by histopathological, immunohistochemical and electron microscopic examinations. Histologically, chordoid glioma comprised the major part of the tumor, and the prominent Rathke's cleft cysts were distributed focally in the same tumor tissue without any transitions. Chordoid glioma was immunoreactive for glial fibrillary acidic protein, S-100 protein and vimentin, and focally positive for epithelial membrane antigen and CD34, while cytokeratin highlighted epithelial cells lining Rathke's cleft cysts. Ultrastructural examination of the chordoid glioma revealed short cytoplasmic processes, intermediate filaments, intercellular junctions of zonular adherens type, basal lamina, secretory granules and pinocytic vesicles. The ultrastructural observations of the current case are similar to those of the subcommisural organ, although cell body zonation or microvilli were not evident. The coexistence of chordoid glioma and Rathke's cleft cyst has not been reported previously and may represent a collision tumor.

Chordoid glioma: report of a case with unusual histologic features, ultrastructural study and review of the literature

Chordoid gliomas are an uncommon primary brain tumor with histologic features of a chordoma and immunolabeling for glial fibrillary acid protein. We report the 32nd case with a review of the literature. The clinical, radiographic and pathologic features of the tumor are presented with new pathologic findings adding support that this lesion may be of ependymal origin. Treatment and long term outcome are limited but chordoid gliomas appear to be indolent lesions that may be cured with gross total resection.

Third ventricular chordoid glioma: case report and review of the literature

BACKGROUND

Chordoid glioma of the third ventricle is a rare type of brain tumor that was recently characterized as a novel tumor entity. We present a case and review of the literature.

CASE REPORT

A 49-year-old woman presented with progressive headache, memory impairment and urinary incontinence. MRI showed a large well-circumscribed tumor in the third ventricle. The tumor was partially removed via a trans-lamina terminalis approach. The histologic findings indicated chordoid glioma. Residual tumor was treated by stereotactic radiosurgery and showed no regrowth at 2-year follow-up.

CONCLUSIONS

The ideal therapy is total removal of the tumor. However, according to the literature, total removal of the tumor carries a high risk because of its location, and conventional radiation therapy has little effect on the residual tumor. On the other hand, stereotactic radiosurgery appears more promising, and to date, no regrowth has been reported after gamma-knife therapy.

Chordoid glioma of the third ventricle: a report of two new cases, with further evidence supporting an ependymal differentiation, and review of the literature

The term chordoid glioma of the third ventricle was first used to describe a rare and slowly growing neoplasm of uncertain histogenesis, with chordoid appearance, occurring preferentially in middle-aged women. Herein we report two additional examples of this novel entity together with a literature review based on the 25 cases previously published. Our review fully confirms the strikingly stereotyped clinical, neuroradiologic, and pathologic features of this unique tumor. The female/male ratio was 1.7:1, and the age range was 24-70 years (mean 44.9 years). In all 27 cases imaging findings were similar showing a well-defined mass (mean 2.8 cm in largest dimension), ovoid in shape, hyperdense on CT scans, with uniform and intense contrast enhancement, arising in the hypothalamic/suprasellar/third ventricular region. Histologically, the main consistent characteristics were cords and clusters of epithelioid cells within an abundant mucinous and often vacuolated background. Mitoses were sparse or absent and anaplastic features, endothelial proliferation, and necrosis were not identified. Lymphoplasmacytic infiltrates with Russell bodies were frequent throughout the tumor and its interface with adjacent brain parenchyma. Most of the tumor cells revealed a strong and diffuse expression of vimentin and glial fibrillary acidic protein. Additionally, the vast majority of tumors showed focal coexpression of cytokeratins, CD34, S-100 protein, and epithelial membrane antigen; the MIB-1 labeling indices were uniformly low. Surprisingly for a glioma assigned WHO grade II, the 19 patients with an available but short follow-up (mean 22.5 months; range 6-68 months) experienced a rather poor outcome (three recurrences and seven deaths), probably reflecting the anatomic site of the neoplasm that precludes a complete surgical excision rather than its histologic composition. Ultrastructural examination of 10 cases demonstrated findings in line with a glial derivation and a putative ependymal origin such as cytoplasmic intermediate filaments, microvilli, intermediate junctions or desmosomes, and focal basal lamina formation. In our case no. 1, and for the first time in this tumor, we observed sparse and abnormal cilia in an aberrant juxtanuclear location, a further argument for considering chordoid glioma as a subtype of ependymoma. However, a better understanding of the biologic behavior and histogenesis of this distinctive clinicopathologic entity needs to be investigated with a larger series. Nevertheless, taking into account its strikingly consistent anatomic localization, its unique histopathologic and immunohistochemical profile, in conjunction with the most recent and convincing ultrastructural arguments, we suggest that chordoid glioma of the third ventricle could be better classified as chordoid ependymoma of the lamina terminalis area.

Choroid plexus cyst and chordoid glioma. Report of two cases

Several types of mass lesions may occur in the third and lateral ventricles. Typically they arise from the lining of the ventricular cavity or from contiguous structures, by extension into the ventricle. The authors describe two patients, each of whom presented with a different rare lesion of the ventricular system. The first was a 53-year-old woman with a history of hypertension who sustained a blunt traumatic injury to the occipital region and subsequently developed a progressively worsening right-sided headache. Radiological examinations over the next 2 years revealed an enlarged right lateral ventricle and, ultimately, a choroid plexus cyst in its anterior and middle third, near the foramen of Monro, which is a rare location for these lesions. The cyst was removed en bloc, and follow-up examinations showed a significant improvement in her headache and a minimal differences in size between right and left ventricles. The authors also describe a 57-year-old man with hypertension, diabetes mellitus, and an old mycardial infarct, who presented to an outside institution with a progressively worsening headache, generalized malaise, and loss of olfactory sensation. Diagnostic imaging revealed a 1.5-cm oval lesion centered in the lamina terminalis region, an open craniotomy was performed, and evaluation of a biopsy sample demonstrated the mass to be a chordoid glioma of the third ventricle, a recently described glioma subtype. Two days after surgery, he suffered a left parietal stroke and an anterior mycardial infarction. After convalescing, he presented to The University of Texas M. D. Anderson Cancer Center for radiotherapy and follow up; 7 months later he was readmitted complaining of headache, short-term memory loss, and worsening confusion and disorientation. Neuroimaging revealed progression of the tumor (now 2 cm in diameter), which was removed by gross-total resection. His headache resolved immediately, and 2 months later his only complaint was of episodes of confusion. Three weeks later he died of a massive myocardial infarction. These two patients represent the sixth case of an adult with a choroid plexus cyst in the anterior lateral ventricle and the 19th case of an adult with a chordoid glioma of the third ventricle, respectively.

Chordoid glioma of the third ventricle: an ultrastructural study of three cases with a histogenetic hypothesis

Chordoid glioma is a rare neoplasm occurring in the third ventricle and, as the name implies, having a chordoid appearance. It is currently considered a glial neoplasm of uncertain histogenesis with distinct clinicopathologic features. We report three cases of chordoid glioma with a focus on the ultrastructural appearance. The patients were two men and one woman aged, respectively, 34, 40, and 43 years. Immunohistochemically, all tumors showed strong and diffuse reactivity for glial fibrillary acidic protein and vimentin, whereas immunoreactivity for epithelial membrane antigen and cytokeratin was focal. Ultrastructurally, they showed features of ependymal differentiation for the presence of an apical pole with microvilli and a basal pole characterized, as in normal ependyma, by many hemidesmosomelike structures connecting cell membranes to the underlying basal lamina. Constant features were a submicroscopic cell body zonation (i.e., perinuclear, intermediate, subapical, and apical regions) and the presence of secretory granules. These findings were similar to those described for the secretory ependymal cells of the subcommissural organ, a small structure located in a dorsocaudal region of the third ventricle that undergoes regression after birth in humans. Our observations suggest that chordoid glioma may represent a subtype of ependymoma whose cells resemble the highly specialized ependyma of the subcommissural organ.

Chordoid glioma of the third ventricle: CT and MR findings

We present a case of chordoid glioma involving the third ventricle in a 42-year-old woman. CT and MR showed a homogeneously enhancing mass occupying the third ventricle, with a cystic component. Chordoid glioma should be included in the differential diagnosis of uncommon masses of the third ventricle in middle-aged women.