Intraoperative Magnetic Resonance Imaging Assisted Endoscopic Endonasal Resection of Clival Chordomas

BackgroundCranial base chordomas are typically indolent and usually appear as encapsulated tumors. They slowly grow by infiltrating the bone, along with the lines of least resistance. Due to its relationship with important neurovascular structures, skull base chordoma surgery is challenging.ObjectiveThe usefulness of intraoperative magnetic resonance imaging (IO-MRI) in achieving the goal of surgery, is evaluated in this study.MethodsBetween March 2018 and March 2020, 42 patients were operated on for resection of skull base chordomas in our institution. All of them were operated on under IO-MRI. Patients were analyzed retrospectively for identifying common residue locations, complications and early post-operative outcomes.ResultsIn 22 patients (52,4%) gross total resection was achieved according to the final IO-MRI. In 20 patients (47,6%) complete tumor removal was not possible because of extension to the petrous bone (8 patients), pontocerebellar angle (6 patients), prepontine cistern (4 patients), temporobasal (1 patient), cervical axis (1 patient). In 13 patients, the surgery was continued after the first IO-MRI control was performed, which showed a resectable residual tumor. 7 of these patients achieved total resection according to the second IO-MRI, in the other 6 patients all efforts were made to ensure maximal resection of the tumor as much as possible without morbidity. Repeated IO-MRI helped achieve gross total resection in 7 patients (53.8%).ConclusionsOur study proves that the use of IO-MRI is a safe method that provides the opportunity to show the degree of resection in skull base chordomas and to evaluate the volume and location of the residual tumor intraoperatively. Hence IO-MRI can improve the life expectancy of patients because it provides an opportunity for both gross total resection and maximal safe resection in cases where total resection is not possible.

Multivariate Analysis of Associations between Clinical Sequencing and Outcome in Glioblastoma

Background Many factors impact survival in patients with glioblastoma, including age, Karnofsky Performance Status, post-operative chemoradiation, IDH1/2 mutation status, MGMT promoter methylation status, and extent of resection. High-throughput next generation sequencing is a widely available diagnostic tool, but the independent impact of tumors harboring specific mutant genes on survival and the efficacy of extent of resection are not clear. Methods We utilized a widely available diagnostic platform (FoundationOne CDx) to perform high-throughput next generation sequencing on 185 patients with newly diagnosed glioblastoma in our tertiary care center. We performed multivariate analysis to control for clinical parameters with known impact on survival to elucidate the independent prognostic value of prevalent mutant genes and the independent impact of gross total resection. Results When controlling for factors with known prognostic significance including IDH1/2 mutation and after multiple comparisons analysis, CDKN2B and EGFR mutations were associated with reduced overall survival while PTEN mutation was associated with improved overall survival. Gross total resection, compared to other extent of resection, was associated with improved overall survival in patients with tumors harboring mutations in CDKN2A, CDKN2B, EGFR, PTEN, TERT promoter, and TP53. All patients possessed at least one of these six mutant genes. Conclusions This study verifies the independent prognostic value of several mutant genes in glioblastoma. Six commonly found mutant genes were associated with improved survival when gross total resection was achieved. Thus, even when accounting for known predictors of survival and multiple mutant gene comparisons, extent of resection continues to be strongly associated with survival.

Solitary bone plasmacytoma as posterior fossa cranial neoplasia, presentation of two clinical cases

Background: Solitary bone plasmacytoma is a plasmatic cell dyscrasia; its presentation in the posterior fossa is very rare. Case Description: We present two cases, a 59-year-old male and a 50-year-old female, both with heterogeneous clinical presentation. One had symptoms compatible with endocranial hypertension, and the other presented with a hemispheric cerebellar syndrome and ipsilateral trigeminal neuralgia. They were both related to an intraosseous tumor of the occipital region near the torcula with large extension to the posterior fossa. The diagnosis of a plasma cell neoplasm arising from the diploe of the squamous portion of the occipital bone was confirmed with immunohistochemistry. Conclusion: The treatment for a cranial tumor that is suspected to be a solitary bone plasmacytoma requires a multidisciplinary team to diagnose, plan a total resection, and after surgery continue with the follow-up of the patient. Solitary bone plasmacytoma should be considered as a differential diagnosis for a tumor that produces cancellous bone widening without sclerotic borders.

Cranial Fasciitis in Children: Expanding the Spectrum of USP6-Associated Clonal Transient Neoplasms

Background: Cranial fasciitis (CF) is a benign (myo)fibroblastic proliferation of children. Typical presentation consists of a rapidly growing solitary mass on the temporal or parietal cranium in the first 2 years of age. CF is characterized by a rapid growth followed by a relative slowdown and even growth arrest. The finding of somatic USP6 gene rearrangements demonstrating clonality in CF together with its clinical behavior places it in the category of diseases recently termed “transient neoplasia.” Methods: Histological, immunohistochemical, and molecular findings of 18 patients with CF were retrospectively studied. Results: The tumor typically presented as a painless rapidly enlarging mass in the temporal region. Sixty-six percent of the cases harbored USP6 gene rearrangement. Nine patients were treated with gross total resection (GTR) and 9 with subtotal tumor resection (STR). Two patients treated with GTR had recurrence. Five patients treated with STR had progression-free disease for at least 10 months after surgery and in four patients the tumor regressed spontaneously a median 16 months after surgery. Conclusions: In this largest series to date, we reported the clinicopathological, immunohistochemical, and molecular findings of 18 pediatric cases of CF with emphasis on the clinical growth pattern of these tumors.

Endoscopic Endonasal Intraconal Approach for Orbital Tumor Resection: Case Series and Systematic Review

Intraorbital tumor could be approached by numerous surgical methods. The neuroendoscopic endonasal approach could provide a feasible corridor for indicated tumors. Herein we present a series of 6 consecutive intraorbital tumors from April 2018 to October 2020, which received endonasal endoscopic resection. Cadaveric dissection was performed for the intraconal approach, and the literature was also reviewed. Five tumors were located intraconally, while one extraconally. The pathology revealed 1 angioleiomyoma, 1 cavernous hemangioma, 1 pilocytic astrocytoma, 1 meningioma, and 2 schwannomas. Five of the six achieved gross total resection, including 3 tumors with lateral extension beyond the optic nerve. Preoperative visual deterioration was observed in 4 of the 6 patients, and all got improvement postoperatively. Transient oculomotor nerve palsy was presented in one patient postoperatively. No cerebrospinal fluid leakage, enophthalmos, or strabismus was observed. The median follow-up time is 27 months (11~41 months). At the 6-month follow-up, the visual acuity remained unchanged compared with that at discharge. Proptosis was resolved in 2 of the 3 patients; diplopia was improved in one patient. In conclusion, endoscopic endonasal intraconal approach could be suitable for selected pathological conditions, and for both medial or beyond medial extraconal and intraconal orbital tumors.

The association of ectopic craniopharyngioma in the fourth ventricle with familial adenomatous polyposis: illustrative case

BACKGROUND Craniopharyngioma (CP) often arises in the sellar and suprasellar areas; ectopic CP in the posterior fossa is rare. Familial adenomatous polyposis (FAP) is a genetic disorder involving the formation of numerous adenomatous polyps in the gastrointestinal tract, and it is associated with other extraintestinal manifestations. OBSERVATIONS The authors reported the case of a 63-year-old woman with FAP who presented with headache and harbored a growing mass in the fourth ventricle. Magnetic resonance imaging (MRI) findings revealed a well-circumscribed mass with high intensity on T1-weighted images and low intensity on T2-weighted images and exhibited no contrast enhancement. Gross total resection was performed and histopathology revealed an adamantinomatous CP (aCP). The authors also reviewed the previous reports of ectopic CP in the posterior fossa and found a high percentage of FAP cases among the ectopic CP group, thus suggesting a possible association between the two diseases. LESSONS An ectopic CP may be reasonably included in the differential diagnosis in patients with FAP who present with well-circumscribed tumors in the posterior fossa.

Contralateral interhemispheric transfalcine approach to precuneal glioblastoma: fluorescein guided microsurgical resection and endoscopic microinspection tool

Maximum safe resection remains a primary goal in the treatment of glioblastoma, with gross-total resection conveying additional survival benefit. Multiple intraoperative visualization techniques have been developed to improve the extent of resection. Herein, the authors describe the use of fluorescein and endoscopic assistance with a novel microinspection device in achieving a gross-total resection of a deep seated precuneal glioblastoma. An interhemispheric transfalcine approach was utilized and microsurgical resection was completed with fluorescein guidance. A 45° endoscope was then used to inspect the resection bed, and remaining areas of concern were then resected under endoscopic visualization. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21195

Unveiling a Ghost Proteome in the Glioblastoma Non-Coding RNAs

Glioblastoma is the most common brain cancer in adults. Nevertheless, the median survival time is 15 months, if treated with at least a near total resection and followed by radiotherapy in association with temozolomide. In glioblastoma (GBM), variations of non-coding ribonucleic acid (ncRNA) expression have been demonstrated in tumor processes, especially in the regulation of major signaling pathways. Moreover, many ncRNAs present in their sequences an Open Reading Frame (ORF) allowing their translations into proteins, so-called alternative proteins (AltProt) and constituting the “ghost proteome.” This neglected world in GBM has been shown to be implicated in protein–protein interaction (PPI) with reference proteins (RefProt) reflecting involvement in signaling pathways linked to cellular mobility and transfer RNA regulation. More recently, clinical studies have revealed that AltProt is also involved in the patient’s survival and bad prognosis. We thus propose to review the ncRNAs involved in GBM and highlight their function in the disease.