Surgical Management of Craniovertebral Junction Schwannomas: A Systematic Review

Surgical Management of Extradural Tumors at the Craniovertebral Junction - Insights from a Tertiary Care Center

BACKGROUND

Craniovertebral junction (CVJ) tumors are challenging due to their unique anatomical location. This study aimed to evaluate the complexities in dealing with such precarious CVJ extradural lesions over the decade.

METHODS

Twenty-seven patients of extradural CVJ tumors operated between 2009 and 2018 were included. The demographic details, neurological status, surgical approach, extent of resection, type of fixation, complications, and outcome at final follow-up were recorded for each patient.

RESULTS

The mean age of the patients was 39.5 ± 20 years. Most (17/27) of the patients had involvement of a single level. Clivus was the most common (9/17) involved region followed by atlas (7/17) vertebrae. Majority of the patients (13/27) were operated through the posterior-only approach. About 15 patients (55.5%) had instability or extensive lesions that necessitated posterior fixation. None of the patients underwent anterior fixation. Gross and near total excision were achieved in 10 patients (37%) and 3 patients (11%) respectively while 14 patients underwent subtotal excision of tumor. On histopathological analysis, clival chordoma (8/27) was found to be the most common pathology followed by giant cell tumor (6/27), plasmacytoma (4/27), and multiple myeloma (2/27). Most patients (13 out of 27) had the same neurological status after the surgery. Six patients (22%) improved post-operatively with decreased weakness and spasticity. Thirteen (48%) patients underwent adjuvant radiotherapy.

CONCLUSIONS

This retrospective study provides valuable insights into managing extradural CVJ tumors and highlights the importance of individualized approaches for optimal outcome.

Tumor-Like Lesions in the Craniovertebral Junction: A Case Series, Systematic Review, and Meta-Analysis

Background: Tumor-like lesions at the craniovertebral junction mimic tumors in clinical presentation and imaging. Our study focuses on three common developmental pathologies-epidermoids, dermoids and neurenteric cysts. Methods: We conducted a retrospective analysis of a case series and a meta-analysis of 170 patients from 119 reports. Results: Neurenteric cysts predominated (81.2%). Anterior cysts were linked to neurenteric cysts, while posterior ones correlated with dermoid/epidermoid cysts (p < 0.001). Complications occurred in 27.2% of cases, with cranial nerve paresis being the most common. Most patients had excellent outcomes (75.2%) with low recurrence rates (12%). Dermoid cysts were more associated with anomalies (p < 0.001). Among 138 neurenteric cyst cases, 15 experienced recurrence, with predictors including ages 51-60 and over 70, subtotal resection, complications, and poor outcomes (p < 0.001). Cysts with total resection were significantly less likely to adhere to surrounding brain tissue (p < 0.001). CSF diversion was correlated with older age (p = 0.010) and various complications (p < 0.001). Age affected outcomes, and the hydrocephalus was linked to poor outcomes (p = 0.002). Conclusions: This meta-analysis underscores the importance of total resection in minimizing recurrence rates and emphasizes meticulous preoperative planning and imaging. Our results indicate that rim enhancement (p = 0.047) and poor outcome (p = 0.007) are significant factors associated with recurrence. Additionally, associated anomalies, as well as the patient's age and overall health, significantly influence the surgical outcomes and the likelihood of recurrence.

Accessory Nerve Schwannoma with Medulla Oblongata Compression: Microsurgical Resection by Far Lateral Suboccipital Transcondylar Approach: 2-Dimensional Operative Video

Schwannomas overall account for approximately 8% of primary brain tumors, with the majority of them arising from the vestibular nerves.1,2 Non-vestibular schwannomas are considered rare, particularly ones arising from the accessory nerve, constituting only around 4% of craniovertebral junction schwannomas.3,4 The far lateral approach and its variations is an important tool in the armamentarium of skull base neurosurgeons. It allows adequate exposure for accessing ventral and ventrolateral lesions of the craniocervical junction.5-13 A 60-year-old female patient presented with a 3-month history of difficulty walking and progressive right-sided weakness. Magnetic resonance imaging demonstrated an extra-axial solid lesion at the craniocervical junction with significant enhancement on post-contrast imaging. The lesion was ventrolateral to the medulla, causing compression, displacement, and peritumoral edema. The patient consented to the procedure and underwent a far lateral suboccipital craniotomy with C1 hemilaminectomy in a lateral position. Tumor origins were identified at the left accessory nerve rootlet. The patient's postoperative course was uneventful. Follow-up magnetic resonance imaging revealed gross total resection and complete resolution of hemiparesis 3 months after the surgery. Microsurgical resection of tumors at the craniocervical junction is challenging. Preoperative planning and tailoring the approach are essential in the decision-making process to safely perform surgery. This video demonstrates, in detail, the steps, relevant anatomy, and technical nuances for accessory nerve schwannoma ressmoval. To the best of our knowledge, this is the first operative video showing the resection of a pure accessory nerve schwannoma with compression of the medulla. Under our institutional ethical review board regulations, approval was not necessary.

18F-FDG PET/CT revealed sporadic schwannomatosis involving the lumbar spinal canal and both lower limbs: a case report

Schwannomatosis is a rare autosomal dominant hereditary syndrome disease characterized by multiple schwannomas throughout the body, without bilateral vestibular schwannoma or dermal schwannoma. The most common location of schwannomatosis is the head and neck, as well as the limbs, while multiple schwannomas in the lumbosacral canal and lower extremities are relatively rare. In this study, we report a 79-year-old woman diagnosed with schwannomatosis. MRI and contrast-enhanced imaging revealed multiple schwannomas in both lower extremities. An 18F-FDG PET/CT examination revealed that in addition to multiple tumors with increased 18F-FDG uptake in both lower extremities, there was also an increased 18F-FDG uptake in a mass in the lumbosacral canal. These masses were confirmed to be schwannomas by pathology after surgery or biopsy. 18F-FDG PET/CT findings of schwannomas were correlated with MRI and pathological components. Antoni A area rich in tumor cells showed significant enhancement on contrast-enhanced T1WI, and PET/CT showed increased uptake of 18F-FDG in the corresponding area, while Antoni B region rich in mucus showed low enhancement on contrast-enhanced T1WI, accompanied by a mildly increased 18F-FDG uptake.

Incidental craniovertebral junction schwannoma: Surgical or radiosurgical management?

Craniovertebral junction (CVJ) schwannomas are rare tumors, showing direct involvement of the atlanto-occipital and atlanto-axial joints. Microsurgical removal is the standard of care to improve symptoms and local control, but stereotactic radiosurgery (SRS) is an option. Both, surgery, and SRS, may show risks of severe complications. A 41-year-old male was referred to our department after incidental finding of a right-sided C1 tumor. A CT angiogram with 3D reconstructions showed the close relationship between the tumor and the right vertebral artery (VA). A post-contrast enhancement MRI revealed the presence of an extradural mass, sited at the level of the CVJ, mainly at the level of the right articular mass of C1. After multidisciplinary assessment, involving the gamma-knife and neurosurgical teams, we performed a microsurgical resection of the tumor. Histology confirmed the diagnosis of schwannoma. At 1 year follow-up the patient is stable, with no recurrence of the tumor. CVJ schwannoma's current standard of care is surgical resection, but longitudinal studies are required, and should promoted promptly since the recent introduction of the new version of GKSRS that allow the treatment of CVJ's lesions.

Prognostic significance of preoperative neutrophil-to-lymphocyte ratio in surgically resected schwannomas

Objective

The goal of schwannoma resection is to control the tumor while preserving neurological function. Schwannomas have a variable postoperative growth pattern, therefore preoperative prediction of a schwannoma's growth pattern is favorable. This study aimed to examine the relationship between preoperative neutrophil-to-lymphocyte ratio (NLR) and postoperative recurrence and retreatment in patients with schwannoma.

Methods

We retrospectively examined 124 patients who underwent schwannoma resection in our institution. Associations between preoperative NLR, other patient and tumor characteristics, and tumor recurrence and retreatment were analyzed.

Results

Median follow-up was 2569.5 days. Postoperative recurrence occurred in 37 patients. Recurrence that required retreatment occurred in 22. Treatment-free survival (TFS) was significantly shorter in patients with NLR ≥2.21 (P = 0.0010). Multivariate Cox proportional hazards regression showed that NLR and neurofibromatosis type 2 were independent predictors of retreatment (P = 0.0423 and 0.0043, respectively). TFS was significantly shorter in patients with NLR ≥2.21 in the following subgroups: sporadic schwannoma, primary schwannoma, schwannoma ≥30 mm in size, subtotal resection, vestibular schwannoma, and postoperative recurrence.

Conclusions

Preoperative NLR ≥2.21 before surgery was significantly associated with retreatment after schwannoma resection. NLR may be a novel predictor of retreatment and assist surgeons in preoperative surgical decision making.