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

Intracranial Dermoid in Patients With Fibrous Dysplasia

OBJECTIVES

Intracranial epidermoid cyst (EC) and craniofacial fibrous dysplasia (CFD) were histogenetically different rare congenital benign diseases. The coexistence of intracranial EC and CFD was extremely rare and had not been reported yet.

MATERIALS AND METHODS

We retrospectively reviewed the clinical and radiologic information of 3 patients diagnosed with concomitant EC and CFD at Beijing Tiantan Hospital from January 2003 to January 2021 and summarized their clinicopathological features, treatment modalities, and outcomes. In addition, we performed a systematic review of cases of the coexisting intracranial EC and other intracranial abnormalities to explore the potential connections.

RESULTS

There were 2 women and 1 man with the mean age of 31 years old. Satisfactory resection was fulfilled for all the 3 ECs. CFD, however, was managed with watchful waiting. During the mean follow-up time of 58 months, all the ECs showed no sign of recurrence, and all the CFD lesions remained stable. Two EC specimens underwent genetic study, showing no GNAS mutations and negative Gsα protein expression. In the literature review of concomitant intracranial EC and other intracranial abnormalities, 23 studies were included. With 5 reported cases, the intracranial aneurysm was found to be the most common intracranial disease that coexisted with EC.

CONCLUSIONS

The coexistence of intracranial EC and CFD was extremely rare. However, no convincing mechanism and evidence underlying such coexistence had been found. To provide more profound understanding about these 2 diseases and improve diagnosis and treatment strategy, further research and verification should be considered.

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: an entity occurring not exclusively in the third ventricle

Chordoid gliomas are extremely rare entities, which are generally considered occurring exclusively in the third ventricle. Despite the low-grade histological grade, aggressive behaviors have been reported in literatures. Due to the low morbidity, the origins, clinical, and radiological features, management and prognosis are still yet to be well elucidated. We retrospectively reviewed the clinical profiles from a series of 6 patients with chordoid gliomas. All patients underwent surgical treatment, and the diagnoses were based on histopathological examinations. Magnetic resonance imaging (MRI) was performed perioperatively. Follow-up outcomes were presented. This case series consisted of three male and three female patients (age range 27-67 years; mean age 43.3 years). MRI results showed tumors in the third ventricle (4/6), temporal-parietal-occipital lobe involving the lateral ventricle (1/6), and cerebellar hemisphere (1/6). Three tumors were solid, and the others were cystic-solid. Hydrocephalus was present in one patient. The T1-weighted imaging showed hypo- to isointensity, and T2-weighted imaging showed iso- to hyperintensity; enhancement was homogeneous (4/6) or heterogeneous (2/6). Diffusion-weighted imaging showed no evidence of restricted diffusion. Magnetic resonance spectrum showed an elevated choline value and reduced N-acetylaspartate value. Gross total resection was achieved in all patients, and during an average follow-up period of 35.8 months, no recurrence was noted. Chordoid gliomas can occur outside the third ventricle with a great diagnostic challenge. The MRI characteristics suggest a low-grade tumor, and the accurate diagnosis depends on pathological criteria. Complete surgical resection is associated with a favorable outcome.

Glioblastoma formation in a recurrent intracranial epidermoid cyst: a case report

Background:

Transformation to glioblastoma following recurrent epidermoid cyst resection has not been reported. Chronic inflammation can underlie malignant transformation of epidermoid cysts. Astrogliosis following repeated resections may have induced the rare transformation to glioblastoma.

Clinical presentation:

A patient presenting with left lower extremity weakness was found to harbor a parietal mass lesion. Histopathology demonstrated an epidermoid cyst. Following multiple re-resections, an intra-axial mass was discovered within the operative bed, confirmed as glioblastoma.

Conclusion:

This is the first report of glioblastoma associated with a resected epidermoid cyst. Subsequent to resection, the chronic inflammatory milieu propagated by astrogliosis is thought to have induced malignancy. The progression to glioblastoma draws attention to neoplastic transformation in the context of recurrent epidermoids.