Cervicomedullary Tumor Research Articles

HGG-44. BRAINSTEM HIGH-GRADE ASTROCYTOMA WITH PILOID FEATURES (HGAP) WITH AN NTRK FUSION: A HISTOLOGICAL MIMICKER AND RARE PEDIATRIC BRAIN TUMOR

Abstract BACKGROUND HGAP is a recently defined rare glial neoplasm, whose classification requires pathognomonic epigenetic signatures. HGAP can arise anywhere within the central nervous system but most have been reported in the cerebellum (74%). Rarely seen in children, the diagnosis of HGAP can be challenging due to morphologic overlap with other glial neoplasms, especially pilocytic astrocytoma (PA). CASE We present an 11-year male with history of poor weight gain and bilateral sensorineural hearing loss detected on routine screening. Examination showed ataxia, with nystagmus on lateral gaze. MRI brain showed a solid/cystic, dorsally exophytic, cervicomedullary tumor with extension into the 4th ventricle, and hydrocephalus. The tumor showed heterogeneous enhancement with no restricted diffusion, nor intracranial or spinal metastases. Histologic sections from the biopsy suggested classic biphasic PA, with abundant Rosenthal fibers, vascular sclerosis, and no obvious mitoses. Ki67 index was low (<5%; hotspots up to 5-10%+). ATRX mostly retained, even within the most atypical nuclei. The histological impression was classic PA. Comprehensive molecular analysis with DNA methylation showed a high confidence match (0.9883) for HGAP. Paired exome sequencing revealed CDKN2A/2B biallelic loss, missense variant and copy number loss involving NF1, loss of function splice variant in ATRX with no germline alterations detected. Interestingly, fusion panel revealed a BCR::NTRK2 fusion. He received focal photon radiation (54Gy) and adjuvant therapy with Larotrectinib. He remains well with stable disease (EFS 7months). CONCLUSION A comprehensive 2023 review of literature revealed only 14 pediatric cases (range 4-18yo) out of 144 reported cases. Including our patient, 9 were male; 8 posterior fossa, 4 supratentorial, 1 spinal cord, and 2 of unknown location. Molecular analysis of the previously reported 14 pediatric cases showed only one case with a different NTRK fusion. We herein present a unique pediatric HGAP, with entirely classic biphasic and benign PA-like features, brainstem location, and targetable NTRK2 fusion.

Reliability and Predictors of Intraoperative Neuromonitoring Changes During Intramedullary Tumor Resection: A Multicenter Experience

INTRODUCTION: Intraoperative neuromonitoring (IONM) is used in real-time to alert neurosurgeons of potential neurological changes when resecting intramedullary spinal cord tumors (IMSCTs). Previous studies have reported variable reliability of IONM. METHODS: A multicenter retrospective study was performed on patients undergoing IMSCTs surgery with neuromonitoring at the three Mayo Clinic sites between 2005 to 2022. Demographics, SSEP, MEP changes and postoperative outcomes were recorded. Specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Variables found significant on univariate analysis (p < 0.05) were applied to a multivariate model to identify predictors for IONM SSEP and MEP changes. RESULTS: 135 patients underwent surgical resection for IMSCTs using IONM. The mean age at diagnosis was 45 ± 17.9 years. Laminectomy was the most frequent index operation (96.3%). A total of 8.9% of patients presented with short-term improvement, while 70.4% presented long-term improvement on their baseline McCormick Scale. Sensitivity, specificity, PPV, NPV, accounted for 86.2%, 51%, 5.2%, 99.2% for MEP; 77.8%, 48.2%, 4.4%, 98.6% for SSEP. We found predictors of IONM changes: poorly defined MEP baseline (OR 3.004, 95% CI 1.22-7.397, p = 0.017), WHO grade II tumors (OR 2.334, 95% CI 1.043-5.223, p = 0.039), cervicomedullary junction location (OR 0.103, 95% CI 0.011-0.983, p = 0.048). Only WHO grade II tumors (OR 2.85, 95% CI 1.208-6.727, p = 0.017) was a predictor for SSEP changes. CONCLUSIONS: Our study represents the largest cohort describing sensitivity, specificity, and predictive factors for intraoperative changes and postoperative outcomes of resection of IMSCTs. A poorly defined baseline and cervicomedullary tumor location were predictors of IONM MEP changes, whiIe WHO grade II tumors were a predictor for both IONM SSEP and MEP changes.

Pediatric low grade focal brainstem glioma: outcomes of different treatment strategies and prognostic factors

Background: This study explores the prognostic factors and outcomes of different treatment modalities in focal brain stem glioma (FBSG). Materials & methods: Pediatric FBSG patients diagnosed during 2010-2017 were retrospectively reviewed for clinical and therapeutic data. Results: A total of 71 cases were identified and the median age was 6.4 years. The 5-year overall- and progression-free survival were 74.5 and 70.6%, respectively. Radiotherapy was the main line of treatment (66.2%) and there were no survival differences between radiotherapy, chemotherapy and surveillance groups. Two independent poor prognostic factors were identified on multivariate analysis: age <8 years and cervicomedullary tumor site (p = 0.02 for both). Conclusion: Surveillance, radiotherapy and chemotherapy have comparable clinical outcomes in pediatric FBSG.

Microsurgery for Cervicomedullary Tumor: 2-Dimensional Operative Video.

The treatment of brainstem tumors are challenging for the neurosurgeons due to the delicate nature of this region. These tumors present a bimodal incidence, with one peak occurring during childhood, where up to 18% of all tumors manifest, while the other occurs during the fourth decade of life. The classic clinical presentation for brainstem tumors is the involvement of cranial nerves. About 90% of the cases have glial etiology, allowing the radiological classification of these tumors into 4 different types: type 1, diffuse; type II, focal, limited, and slow-growing tumors; type III, exophytic tumors, mostly low-grade gliomas, and type IV, cervicomedullary tumors, which may commonly present as an exophytic lesion. We present a 52-yr-old patient with a type IV tumor. The patient reported a history of high cervical pain, which started about 2 mo after admission, and was associated with lower right limb paresthesia. Examination of the cervical and encephalic regions using magnetic resonance imaging revealed a tumor located in the posterior medulla oblongata medial line, near the fourth oblique ventricle. Resection of the lesion was performed using a median suboccipital approach, with subsequent entrance to the oblong medulla via the median posterior sulcus. The lesion was successfully resected. Following surgery, the patient maintained the initial evocated potentials and previous paresthesia in the lower right limb. Pathologic examination revealed that the tumor was a grade II ependymoma. Herein, we present a video demonstrating the microsurgical steps that were required to perform the cervicomedullary tumor resection. The patient signed the Institutional Consent Form, which allows the use of his/her images and videos for any medical publications in conferences and/or scientific articles.Watch now at https://academic.oup.com/ons/article-lookup/doi/10.1093/ons/opy024 {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Microsurgery for Cervicomedullary Tumor: 2-Dimensional Operative Video","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_x4kowbwi"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} Disclosure The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.

P.083 Trigeminal neuralgia caused by an intra-axial glioma in a child: first surgical case report and systematic review

Background: Trigeminal neuralgia (TGN) is usually caused by arterial compression of the trigeminal nerve. There are very few cases caused by intra-axial brainstem masses. Little information is therefore available regarding the response to incomplete resection of offending lesions. We present one such case, and systematically review the published in the literature. Methods: Case report and systematic review of MEDLINE and EMBASE Results: Case report: A seven year-old girl is referred with typical TGN pain. MRI revealed a cervicomedullary tumor with no abnormalities of the pons or trigeminal nerve. Subtotal resection under neurophysiologic monitoring was achieved, leaving a small residual attached near the expected location of the trigeminal spinal nucleus and tract.Patient recovered well with resolution of her TGN pain. She is asymptomatic seven years post-operatively. Literature Review: We found no other published cases in children or secondary to gliomas. Among reviewed cases, only two underwent surgery. Both were adults with brainstem cavernomas and both reported substantial improvement despite incomplete resection. Conclusions: Our case as well as literature review both show that surgical resection is beneficial in such cases and, even if subtotal, can result in substantial pain relief. This suggests intra-axial compression of the trigeminal spinal nucleus and tract as the possible cause of TGN pain in such cases.

Neurofibromatosis-2 and spinal cord ependymomas: Report of two cases and review of the literature

The incidence of ependymoma in patients with neurofibromatosis-2 (NF-2) is low and information regarding treatment and prognosis is lacking. We present two cases of cervicomedullary tumors in patients with NF-2 from our institution, and we provide a review of the literature in order to summarize the known clinical information about this rare occurrence. Patient #1 had histological confirmation of ependymoma and was treated with subtotal resection followed by observation and has had no evidence of progression for 11 months. Patient #2 has been observed for 4 1/2 years without treatment for a cervicomedullary tumor, which appears to be an ependymoma by imaging. Although it has increased in size very slowly, there have been no clinical symptoms. Among the additional 21 cases of NF-2 and ependymoma from the literature, the most common location is the cervical spine (70%), and the median age at diagnosis is 15 years. Surgical resection was performed in 85% of the cases and subtotal resection in 64% of cases. Fifteen patients (75%) were reported alive at the time of the published reports, with survival ranging from 0.1 to 10 years, and the 8-year survival estimated as 51%. Survival was related to the location of the tumor. We conclude from our two cases and review of the existing literature that NF-2 associated spinal ependymomas have an indolent course and typically can be observed or treated by surgical excision alone.

Endoscopic third ventriculocisternostomy for brainstem tumors

The authors retrospectively reviewed the charts of all patients harboring brainstem tumors treated at their institution, excluding those with tectal gliomas, who underwent an endoscopic third ventriculocisternostomy. Endoscopic third ventriculocisternostomy was performed in 13 patients with tumors involving the brainstem: nine patients with diffuse pontine gliomas, two with posterior fossa ependymomas, one with a cervicomedullary tumor, and one with a pontine primitive neuroectodermal tumor. No technical difficulties attributable to the location of the tumors or surgery-related complications were encountered. Immediate symptomatic relief of hydrocephalus was achieved in all patients, and there was an associated decrease in steroid and analgesic agent requirements. Only one patient eventually required a shunt. Endoscopic third ventriculocisternostomy can be used in the terminal treatment of patients with brainstem tumors, yielding good results without significant surgical morbidity.

Cervicomedullary Tumors

The perioperative course and outcome of 17 children who underwent surgical resection of an intra-axial cervicomedullary tumor between 1980-1992 are reported from the Departments of Pediatrics and Neurology, University of Michigan Medical Center, Ann Arbor, MI, and New York University Medical Center, New York, NY.

Intraoperative Localization of a Cervicomedullary Glioma from the Killed End Potential: Illustrative Case

Abstract We recorded the intraoperative somatosensory evoked potentials directly from the upper cervical cord and medulla in a patient with an intrinsic tumor at the region of the cervicomedullary junction. The killed end potential, a large positive potential, was obtained at the caudal end of the tumor. This type of potential occurs when an impulse approaches but never passes beyond the recording electrode. Myelotomy guided by the killed end potential enabled appropriate spinal and medullary dissection and led to early encounter with the cervicomedullary tumor.

Intraoperative localization of a cervicomedullary glioma from the killed end potential

We recorded the intraoperative somatosensory evoked potentials directly from the upper cervical cord and medulla in a patient with an intrinsic tumor at the region of the cervicomedullary junction. The killed end potential, a large positive potential, was obtained at the caudal end of the tumor. This type of potential occurs when an impulse approaches but never passes beyond the recording electrode. Myelotomy guided by the killed end potential enabled appropriate spinal and medullary dissection and led to early encounter with the cervicomedullary tumor.