The Role of Surgery in Spinal Intradural Metastases from Renal Cell Carcinoma: A Literature Review

Exoscopic-Endoscopic Resection of Intramedullary Spinal Cord Metastasis From Renal Cell Carcinoma With Ventral Exophytic Extension

Intramedullary spinal cord metastasis (ISCM) is a rare manifestation of renal cell carcinoma (RCC). A 73-year-old man presented with left shoulder pain and left upper extremity weakness for two months. Magnetic resonance imaging (MRI) revealed intramedullary and intradural extramedullary lesions at the C5 level, compressing the spinal cord from the center of the cord and the left ventral side. Contrast-enhanced CT revealed a right renal mass and brain MRI showed no other lesions. Digital subtraction angiography showed a tumor stain from the anterior spinal artery and subsequent angioarchitecture of the intra- and extramedullary tumors. Following exoscopic resection of the extramedullary tumor, the intramedullary tumor was removed via a posterior midline myelotomy. The tumor surrounding the anterior spinal artery was intentionally left to prevent neurological deficits. The histopathological examination revealed metastatic clear cell RCC. Postoperative MRI revealed a small residual tumor ventral to the spinal cord. The nephrectomy for the right RCC was performed one month after the initial spinal surgery. Within the subsequent one month, the residual tumor rapidly increased in size. Reoperation with exoscopic-endoscopic techniques achieved complete tumor resection. The patient underwent radiotherapy to the C3-6 levels (30 Gy in 10 fractions) and pembrolizumab therapy. Postoperative MRI demonstrated no recurrence for four months, and the patient's symptoms remained in the same preoperative state. This case highlights the successful use of advanced minimally invasive techniques for treating ventrally exophytic ISCM from RCC.

The "Pigmented Side" of Nerve Sheaths: Malignant Melanotic Nerve Sheath Tumor

Malignant melanotic nerve sheath tumor (MMNST) represents a highly aggressive neoplasm arising both in peripheral and cranial nerves. It accounts for < 1% of all nerve sheath tumors, but the real incidence may not be well defined yet because of the evolution of its nomenclature. To date, it is considered a distinct tumor type, no longer as the pigmented variant of schwannoma, with a different clinical course and biological behavior. MMNSTs exhibit a specific genetic hallmark related to the PRKAR1A gene, which explains the major incidence in Carney Complex-affected patients. One of the more frequent localizations is the paravertebral region, where it poses diagnostic concerns with both primary tumors arising from soft tissues and the meningeal covering, as well as metastatic ones (ie, melanoma). Herein we present a patient with an MMNST accompanied by the main clinical, radiological, histopathological, and molecular findings, stressing the need for a multidisciplinary diagnostic approach. To the best of our knowledge, this is the first report of proton beam therapy for MMNST. We also performed a literature review to collect and compare the more recent data in English literature and to highlight the "keep-in-mind" concepts to apply in a multidisciplinary diagnostic algorithm, with a focus on histopathology and related pitfalls.

Evolution of Thoracic Disc Herniation Surgery: Future Perspectives from a Systematic Review and Meta-Analysis

BACKGROUND

The neurosurgical treatment of thoracic disc herniation (TDH) has undergone dramatic changes over the years in terms of surgical approaches and intraoperative technological tools. There is still no unanimous consent on the criteria for approach selection, and the choice varies among Institutions. The aim of this study is to compare anterior and posterolateral approaches for TDH in terms of functional and surgical outcomes.

METHODS

A systematic literature review and meta-analysis according to PRISMA guidelines from EMBASE, PubMed, Cochrane Library, Web of Science, and Google Scholar online databases up to May 2024 incorporated studies that reported outcomes of thoracic disc herniation surgeries. Analyzed factors included major peri- and postoperative complications, intraoperative blood loss, hospital stay, neurological improvement, and complete hernia resection. Random-effect models were used to calculate pooled odds ratios and mean differences.

RESULTS

The posterolateral approach was associated with significantly lower rates of major medical (OR 0.14, 95% CI: 0.07 to 0.27) and surgical complications (OR 0.61, 95% CI: 0.38 to 0.99) compared to the anterior approach. Additionally, posterolateral approaches reduced intraoperative blood loss and shorter hospital stays. Posterolateral techniques were linked to higher odds of neurological improvement (OR 0.65, 95% CI: 0.43 to 0.99) and higher rates of complete hernia resection (OR 0.38, 95% CI: 0.21 to 0.71).

CONCLUSIONS

Posterolateral approaches offer advantages in terms of safety, recovery, neurological improvement, and complete hernia resection. More extensive prospective studies are needed to confirm these findings and refine surgical strategies. Emerging technologies, such as the exoscope and 45° endoscopy, may further enhance surgical outcomes.

Transpedicular Corpectomy in Minimally Invasive Surgery for Metastatic Spinal Cord Compression: A Single-Center Series

Introduction The role of separation surgery in managing symptomatic spinal metastases has been increasing in recent years, and it represents a crucial part of the definitive management of this condition. Methods We report on a series of seven patients treated at the National Cancer Institute in Mexico using minimally invasive approaches to perform transpedicular corpectomy. The goal was to obtain a margin of tumor-free tissue, enabling the completion of oncological treatment with radiotherapy. Results We collected data from six cases. The mean age was 61.2 years. Surgical outcomes were good in 83.3% of patients. Ranging from minimally invasive instrumentations to total or partial corpectomies, these procedures achieved their intended function of generating healthy neural tissue free of tumor. This ensures that the radiation gradient does not affect this tissue. No surgical complications were reported. The objective of these surgeries was to establish a radiotherapy or radiosurgery regimen as soon as possible, thereby improving patients' quality of life (QoL). Conclusions Low-cost transpedicular corpectomy via minimally invasive surgery (MIS) is a safe and effective method that meets the goals of separation surgery. However, prospective studies are needed to directly compare open techniques with minimally invasive methods.

Characteristics and Outcome of Surgically Treated Patients with Intradural Extra- and Intramedullary Spinal Metastasis-A Single-Center Retrospective Case Series and Review

OBJECTIVE

Intradural spinal metastases are considered rare. At present, limited information is available on incidence, surgical management, and outcomes.

METHODS

We conducted a retrospective patient chart review from 2002 to 2024, identifying all patients surgically treated for intradural spinal metastases. Clinical, surgical and survival data were collected and compared to literature data for patients surgically treated for extradural spinal metastases.

RESULTS

A total of 172 patients with spinal metastases were identified with 13 patients meeting inclusion criteria (7.6%). The mean age at diagnosis of intradural spinal metastases was 52 ± 22 years, with diverse primaries including lung (n = 3), breast (n = 2), sarcoma (n = 2), and six unique entities. Intradural spinal metastasis was diagnosed on average of 3.3 years after primary diagnosis. In total, we observed five (38%) intradural-extramedullary and eight (62%) intramedullary metastases, located in the cervical (38.5%), thoracic (46.1%) and lumbar spine (15.4%). The most common preoperative symptoms were pain, sensory changes, and gait ataxia (each 76.9%). Gross total resection was achieved in 54%, and local tumor control in 85%. Postoperatively, 92% exhibited clinical improvement or stability. Most frequent adjuvant treatment was radio- and/or chemotherapy in 85%. The average survival after operation for spinal intradural metastases was 5 months, ranging from 1 month to 120 months. The location of the intradural metastasis in the cervical spine was associated with a significantly more favorable survival outcome (compared to thoracic/lumbar location, p = 0.02).

CONCLUSIONS

Intradural location of spinal metastases is rare (7.6%). Even so, surgical resection is safe and effective for neurological improvement, and survival appears lower compared to the reported survival of extradural spinal metastases.

Surgical management of spinal intradural metastatic pathologies: a case-based review

Intradural spinal metastases significantly impair neurological function and quality of life, necessitating multimodal, palliative management to preserve mobility and alleviate pain. The effectiveness of systemic chemotherapy and radiotherapy is limited due to the blood-spinal cord barrier and the tumours' radioresistance, respectively. This highlights the urgency for alternative treatments given the rapid neurological decline. Surgical intervention becomes crucial, focusing on maximum tumour debulking to enhance disease control, restore ambulation, and palliate symptoms without compromising neurological function. Achieving this involves meticulous preoperative planning and aggressive intraoperative neuromonitoring. Combining surgery with adjuvant therapies may improve local control and potentially delay recurrence. This case-based review emphasizes the surgical considerations and outcomes in two cases of intradural spinal metastases, underscoring the value of surgery in multimodal therapy.

Survival and neurological outcomes following management of intramedullary spinal metastasis patients: a case series with comprehensive review of the literature

Intramedullary spinal cord metastasis (ISCM), though rare, represents a potentially debilitating manifestation of systemic cancer. With emerging advances in cancer care, ISCMs are increasingly being encountered in clinical practice. Herein, we describe one of the larger retrospective single institutional case series on ISCMs, analyze survival and treatment outcomes, and review the literature. All surgically evaluated ISCMs at our institution between 2005 and 2023 were retrospectively reviewed. Demographics, tumor features, treatment, and clinical outcome characteristics were collected. Neurological function was quantified via the Frankel grade and the McCormick score (MCS). The pre- and post-operative Karnofsky performance scores (KPS) were used to assess functional status. Descriptive statistics, univariate analysis, log-rank test, and the Kaplan-Meier survival analysis were performed. A total of 9 patients were included (median age 67 years (range, 26-71); 6 were male). Thoracic and cervical spinal segments were most affected (4 patients each). Six patients (75%) underwent surgical management (1 biopsy and 5 resections), and 3 cases underwent chemoradiation only. Post-operatively, 2 patients had an improvement in their neurological exam with one patient becoming ambulatory after surgery; three patients maintained their neurological exam, and 1 had a decline. There was no statistically significant difference in the pre- and post-operative MCS and median KPS scores in surgically treated patients. Median OS after ISCM diagnosis was 7 months. Absence of brain metastasis, tumor histology (renal and melanoma), cervical/thoracic location, and post-op KPS ≥ 70 showed a trend toward improved overall survival. The incidence of ISCM is increasing, and earlier diagnosis and treatment are considered key for the preservation of neurological function. When patient characteristics are favorable, surgical resection of ISCM can be considered in patients with rapidly progressive neurological deficits. Surgical treatment was not associated with an improvement in overall survival in patients with ISCMs.

Sporadic Spinal Hamartoma in Adults: A Rare Pathologic Entity

BACKGROUND

Sporadic spinal hamartomas in adults are extremely rare tumor-like lesions, without defined guidelines of treatment. The aim of this study is to investigate the peculiar features of this pathologic entity to support a more accurate diagnosis and management.

METHODS

A comprehensive and detailed literature review of sporadic spinal hamartomas in adults, including a personal case, was performed. Demographic (sex and age), clinical (presenting symptoms), radiologic and pathologic (size, localization, dural and spinal cord relationship of lesion) features, as well as treatment (time to surgery, extent of resection, perioperative and postoperative complications) and outcome (clinical) data were analyzed.

RESULTS

Seven studies, including 7 patients, were eligible for the review. A personal case was also added. Sporadic adult spinal hamartomas equally affect males and females, in a range of age from 18 to 75 years; sensory radicular deficits were detected in all patients at clinical onset; thoracic segment (4/8) of the spine and intradural compartment (6/8) were most involved. All patients underwent surgery and just one experimented postoperative complication; gross total resection was achieved in only 3 patients, mainly in an extradural localization; clinical improvement at last follow-up was reported in all but 1 patient.

CONCLUSIONS

Spinal hamartomas in adults may sometimes account for progressive worsening of neurologic symptoms and lead to potentially irreversible neurologic deficit; therefore, prompt and adequate diagnosis and treatment are mandatory. Surgical resection represents the only curative treatment and is indicated for symptomatic lesions to achieve neurologic symptoms restoration or arrest/prevent their progressive deterioration.

Surgical resection of lumbar intradural metastatic renal cell carcinoma

A 60-year-old male with renal cell carcinoma (RCC) presented with back pain, weakness, and bowel and bladder urgency. MRI demonstrated a cauda equina tumor at L2. Following L1-3 laminectomies, intraoperative ultrasound localized the tumor. After dural opening, a vascular tumor was adherent to the cauda equina. Intraoperative nerve stimulation helped to identify the nerve rootlets. Tumor was removed in a piecemeal fashion. Tumor dissection caused periodic spasms in L1-3 distributions. A neuromonitoring checklist was used to recover motor evoked potential signals with elevated mean arterial pressures. Hemostasis was challenging with the vascular tumor. Intraoperative ultrasound confirmed tumor debulking. Pathology confirmed metastatic RCC.