Intradural cystic schwannomas of the spine: A case-based systematic review of an unusual tumor.

Introduction: Cystic schwannomas have only been reported in a few case reports/series. As a result, they may be misdiagnosed and a standardized management approach remains challenging to establish. Research question: The aim of this study was to compile all reported cases of cystic schwannomas and analyze the perioperative course based on a systematic review of the literature with an additional two cases from the authors' experience. Material and methods: We conducted a search of MEDLINE and CENTRAL databases for spinal intradural extramedullary cystic schwannomas, in accordance to the PRISMA statement. All title/abstracts were screened, and a full-text review of the remaining articles was conducted. The results were compiled in tables and summarized using means and standard deviation (SD), median and interquartile range, and percentage and 95% confidence intervals. Results: We identified 263 articles, of which 35, which reported 54 cases, were included. Including our case-reports (n = 56), patients had a mean age of 47.7 years (SD ± 13.0 years) at presentation, 57% were males, and most lesions were lumbar (43%). The most common symptoms were pain (82%) and muscle weakness (68%) with 84% of patients showing neurological findings. 70% of patients showed a complete relief of symptoms after surgery and 96% reported improvement. Only four complications were reported. Discussion and conclusion: Schwannomas should be considered in the differential diagnosis of intradural extramedullary cystic lesions. Patients typically present with subacute to chronic pain and/or neurologic changes. Surgical resection is the primary therapeutic modality and usually has a good to excellent outcome.

Spinal Meningiomas: A Comprehensive Review and Update on Advancements in Molecular Characterization, Diagnostics, Surgical Approach and Technology, and Alternative Therapies.

Spinal meningiomas are the most common intradural, extramedullary tumor in adults, yet the least common entity when accounting for all meningiomas spanning the neuraxis. While traditionally considered a benign recapitulation of their intracranial counterpart, a paucity of knowledge exists regarding the differences between meningiomas arising from these two anatomic compartments in terms of histopathologic subtypes, molecular tumor biology, surgical principles, long-term functional outcomes, and recurrence rates. To date, advancements at the bench have largely been made for intracranial meningiomas, including the discovery of novel gene targets, DNA methylation profiles, integrated diagnoses, and alternative systemic therapies, with few exceptions reserved for spinal pathology. Likewise, evolving clinical research offers significant updates to our understanding of guiding surgical principles, intraoperative technology, and perioperative patient management for intracranial meningiomas. Nonetheless, spinal meningiomas are predominantly relegated to studies considering non-specific intradural extramedullary spinal tumors of all histopathologic types. The aim of this review is to comprehensively report updates in both basic science and clinical research regarding intraspinal meningiomas and to provide illustrative case examples thereof, thereby lending a better understanding of this heterogenous class of central nervous system tumors.

Upstream Effects: Intraoperative Migration of Intradural Extramedullary Tumor After Non-Adjacent Level Stenosis Decompression.

A 74-year-old man with back pain, foot numbness, and hip/thigh radiculopathy was found to have an L1-L2 intradural extramedullary neoplasm and severe L4-L5 stenosis. L4-L5 minimally invasive laminectomy for decompression and concomitant L1-L2 minimally invasive laminectomy for tumor resection were planned. L4-L5 laminectomy was completed first followed by the L1-L2 laminectomy. On extensive intradural exploration at L1-L2, no neoplasm was found. Immediate postoperative imaging showed that the intradural extramedullary tumor had migrated caudally by nearly a complete spinal level, presumably due to changes in cerebrospinal fluid pressure and resultant shift in intradural contents after the L4-L5 laminectomy. Successful resection of the intradural extramedullary tumor was performed, with improvement in the patient's symptoms.

Surgical Outcomes and Medical Costs Associated with Spinal Cord Tumors: Comparison of Extramedullary and Intramedullary Tumors.

OBJECTIVE: This study aimed to clarify the differences in the perioperative data of patients with extramedullary and intramedullary tumors and estimate the impact of surgery on medical costs. METHODS: This single-center retrospective study included consecutive patients who underwent spinal tumor resection between September 2020 and December 2022. The perioperative medical information and medical costs for individual patients were obtained from their medical records. RESULTS: Thirty-two patients with extramedullary spinal cord tumors and 18 with intramedullary spinal cord tumors were included in the study. The 2 groups had no difference in surgery-related or major systemic complications. However, the operation time and the length of hospital stay were significantly longer and activities of daily living at discharge tended to worsen in the intramedullary tumor group compared to those in the extramedullary tumor group. As a result, the discharge outcome was significantly different between the 2 groups. The total medical costs for intramedullary tumors were approximately 1.43 times higher than those for extramedullary tumors. Further, a better functional outcome at discharge can save medical costs, regardless of extramedullary or intramedullary tumors. CONCLUSIONS: Surgery for intramedullary tumors can be performed with similar perioperative risks as for extramedullary tumors. However, intramedullary tumors are associated with concerns, such as prolonged hospitalization and worsening of activities of daily living at discharge, which ultimately result in higher medical costs.

Spinal Intradural Extramedullary Tumors: A Retrospective Analysis on Ten-Years' Experience of Minimally Invasive Surgery and a Comparison with the Open Approach.

Spinal intradural extramedullary (ID-EM) tumors are pathologies widely treated through a classical open approach. However, minimally invasive surgery is gaining traction as a comparable treatment option because it carries less morbidity and may reduce healthcare costs.This study aimed to compare the clinical and functional outcomes of open versus minimally invasive approaches for patients with ID-EM tumors. We performed a retrospective analysis on prospectively collected data from patients with ID-EM tumors submitted to surgery. Baseline features and operative variables were compared, including surgery duration and estimated blood loss (EBL). Postoperative data covered tumor histology, length of stay (LOS), complication(s), and neurological status (Medical Research Council (MRC) scale) at the last follow-up.In total, 46 patients were included: 30 (65.2%) operated through an open approach and 16 (34.8%) through a minimally invasive surgical (MIS) approach. The predominant histology type was schwannomas (43.5%). Lesions more frequently affected the lumbar spine (34.8%). The tumor dimensions were similar in both cohorts. The minimally invasive approach was on average 76.7 min faster and correlated positively with less EBL (140 mL less than that of the open approach). Patients in the MIS group had shorter LOSs (5.63 days vs. 17.27 days) and had fewer postoperative complications. No significant difference in functional outcome was found.MIS is as effective as the traditional approach in achieving comparable functional outcomes, with advantages such as shorter surgery durations, less blood loss, and shorter hospital LOSs.

Resection of a large multisegmental filum terminale ependymoma through a multisegmental hemilaminectomy.

This video demonstrates a gross-total resection of a multisegmental intradural extramedullary tumor using only multisegmental hemilaminectomy. The patient is a 21-year-old woman presenting with only backache. MRI of the lumbar spine demonstrates a large multisegmental heterogeneously enhancing intradural extramedullary tumor extending down from the eleventh dorsal vertebrae down to the fifth lumbar vertebrae. The surgical video demonstrates the technique of multisegmental hemilaminectomy and microsurgical resection of the tumor without posterior spinal instrumentation. Postoperatively, the patient had no neurological deficit and was discharged on postoperative day 5. Three-month postoperative MRI shows no residual disease or spinal deformity.

Atypical intradural extramedullary spinal schwannoma causing cauda equina syndrome: A case report and literature review.

INTRODUCTION: Spinal schwannomas are slow-growing benign tumors that are generally asymptomatic. However, we describe an atypical case in which an intradural extramedullary schwannoma presented as an acute cauda equina syndrome. PRESENTATION OF CASE: This was a 58-year-old woman with a 2-month history of severe low back pain and worsening neurological deficits and a 2-day period of acute onset of lower extremity numbness and urinary incontinence. Physical and neurological examination revealed significant lower extremity weakness, tenderness on palpation of the spine, positive straight leg test bilaterally, decreased sensation below the L4 dermatome, reduced sphincter tone, saddle anesthesia, decreased deep tendon reflexes, and loss of sphincter control, consistent with compression of the cauda equina. Magnetic resonance imaging revealed a large mass of heterogeneous composition at the level of L3 lumbar, intruding into the cauda equina. Wide decompression was successfully performed, and histopathological examination confirmed the diagnosis. With rehabilitation, there was some recovery of lower extremity motor function. DISCUSSION: Spinal schwannomas are rare, accounting for only about 2 % of spinal tumors. Cauda equina syndrome is also rare, with an incidence of 0.08-0.27 % among patients presenting with low back pain. Therefore, it is important for clinicians to have an awareness of the possible association between spinal schwannoma and cauda equina syndrome and to complete a comprehensive assessment of patients with back pain, including magnetic resonance imaging. CONCLUSION: Early recognition and treatment of a spinal schwannoma causing neurological symptoms can improve patient outcomes.

Adjuvant multimodal treatment for spinal intradural extramedullary capillary hemangioma with subpial growth: illustrative case.

BACKGROUND: Spinal intradural extramedullary capillary hemangiomas are rare vascular lesions. Although total resection is the first treatment, the efficacy of adjuvant therapies, such as steroid or radiation therapy, has not been investigated. OBSERVATIONS: A 74-year-old man presented with progressive back pain, gait disturbance, and left chest pain. Spinal magnetic resonance imaging (MRI) revealed an intradural extramedullary lesion at the middle thoracic level. Preoperatively, systemic steroid administration improved his chest pain and reduced the tumor size. The authors performed tumor extirpation. Because the tumor strongly adhered to the pia matter, in short, the tumor accompanied with partial subpial growth, subtotal resection was performed, leaving a thin layer of the tumor. A pathological examination revealed capillary hemangioma. His gait disturbance showed rapid improvement. Stereotactic cyber knife treatment was performed for the residual tumor at 1 month after the operation. Serial MRI showed a gradual decrease in the tumor size and no recurrence at 2 years after the operation. LESSONS: When a tumor adheres to the spinal cord or nerve root, immoderate total resection should not be performed to avoid exacerbating the clinical symptoms. Adjuvant therapies, such as a systemic steroid administration or radiation therapy, may provide satisfactory control of spinal capillary hemangiomas.

Endoscopic intradural extramedullary lesion excision: Results of augmented duroplasty with artificial dura.

Objectives: Prevailing techniques of dural closure in endoscopic spine surgery (ESS) for intradural extramedullary (IDEM) tumor excision increase the steep learning curve and operative time. We aimed to assess the efficacy of augmented duroplasty with artificial dura and share our initial experience of ESS for IDEM excision. Materials and Methods: We retrospectively analyzed 18 (n = 18) consecutive patients of IDEM tumors operated by ESS using Destandau's endoscopic system. The pre-operative, post-operative, and at the latest follow-up clinical status were recorded in terms of Nurick's grades and the Oswestry Disability Index. Immediate post-operative complications and intraoperative findings were noted from hospital information system and patient records. Results: The mean (± SD) age of patients was 40.3 ± 14.9 (range 19-64) years, with M: F ratio of 2:1. All the lesions were intradural and present at lumber (n = 6), thoracic (n = 9), and cervical (n = 3) regions. The average duration of surgery, blood loss, hospital stay, and duration of follow-up were 157 ± 45.3 (90-240) min, 168.8 ± 78.8 (30-300) mL, 4.29 ± 1.4 (2-7) days, and 19.3 ± 7.2 (7-36) months, respectively. There were no CSF leaks, wound-related complications, or material-induced adverse events. Conclusion: In endoscopic IDEM excision, dural closure with artificial dura is efficient in preventing CSF leak. It shortens the steep learning curve and improves the surgical outcome due to technical ease.

The Expression of Insulin-Like Growth Factor II Messenger RNA-Binding Protein 3 Upregulated in Intradural Extramedullary Schwannomas.

Introduction: Tumor size is an important factor in determining the appropriate clinical management of intradural-extramedullary schwannoma. A tumor volume reduction may be achieved by conservative targeted therapy instead of invasive surgery if a molecular event related to tumor size is discovered. Insulin-like growth factor II messenger RNA-binding protein 3 (IMP3), an oncofetal tumor-associated antigen that is expected to be a target for immunotherapy, was focused on in this study. Methods: The IMP3 status was assessed by immunohistochemistry in 64 samples of intradural-extramedullary schwannoma, and the correlation between IMP3 expression and tumor size was evaluated. Results: Immunohistochemically, high IMP3 expression was observed in ～85% of schwannomas. The maximum tumor diameter of the high IMP3 expression group was significantly larger than that of the low IMP3 expression group (34.3 mm vs 18.5 mm, p=0.002). The receiver operating characteristic curve demonstrated that a maximum tumor diameter of 24 mm was a predictable factor for IMP3 expression (sensitivity, 0.7; 1-specificity, 0.2; area under the curve, 0.82). Conclusions: Upregulated IMP3 expression was associated with large tumor size, suggesting a possible therapeutic approach.

Characteristics and Postoperative Outcomes for High Cervical versus Subaxial Cervical Intradural Extramedullary Tumors: A Multicenter Study.

BACKGROUND: High cervical intradural extramedullary tumors are uncommon. Their relationship to surrounding neural structures and vertebral arteries makes surgical excision challenging. No previous studies have compared high cervical to subaxial cervical intradural extramedullary spinal tumors to elucidate their unique characteristics and surgical outcomes. METHODS: We performed a retrospective study in which patients who underwent excision of a cervical intradural extramedullary tumor were divided into a high cervical group and a subaxial cervical group. Variables included sex, age, Charlson Comorbidity Index, volume, laterality, preoperative weakness, use of neuromonitoring and drains, instrumented fusion, complications, length of stay, histology, discharge location, recurrence, and duration of follow-up. Variables were compared between the 2 groups. Limb power and Nurick classification were charted preoperatively, at discharge, and at 6 months to plot their recovery trajectory. RESULTS: Eighty-four patients with a total of 90 tumors were enrolled, including 40 patients in the high cervical group and 44 patients in the subaxial spine group. More patients with neurofibromas (P = 0.011) and bilateral tumors (P = 0.044) were in the high cervical group. A greater prevalence of neurofibromatosis type 1 was significant for bilateral high cervical tumors (P = 0.033). More patients in the subaxial group had instrumented fusion (P = 0.045). More patients in the high cervical group had improvement in limb power (P = 0.025) and Nurick classification (P = 0.0001) postoperatively before discharge. By 6 months, both groups had similar recovery. No mortality was attributable to surgery in either group. CONCLUSION: High cervical intradural extramedullary spine tumors have more bilateral tumors associated with neurofibromatosis type 1. Despite the challenging anatomy, surgical resection is safe with good outcomes in this group.

Efficacy of Transcranial Motor Evoked Potential Monitoring During Intra- and Extramedullary Spinal Cord Tumor Surgery: A Prospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

STUDY DESIGN: Multicenter prospective study. OBJECTIVES: Although intramedullary spinal cord tumor (IMSCT) and extramedullary SCT (EMSCT) surgeries carry high risk of intraoperative motor deficits (MDs), the benefits of transcranial motor evoked potential (TcMEP) monitoring are well-accepted; however, comparisons have not yet been conducted. This study aimed to clarify the efficacy of TcMEP monitoring during IMSCT and EMSCT resection surgeries. METHODS: We prospectively reviewed TcMEP monitoring data of 81 consecutive IMSCT and 347 EMSCT patients. We compared the efficacy of interventions based on TcMEP alerts in the IMSCT and EMSCT groups. We defined our alert point as a TcMEP amplitude reduction of ≥70% from baseline. RESULTS: In the IMSCT group, TcMEP monitoring revealed 20 true-positive (25%), 8 rescue (10%; rescue rate 29%), 10 false-positive, a false-negative, and 41 true-negative patients, resulting in a sensitivity of 95% and a specificity of 80%. In the EMSCT group, TcMEP monitoring revealed 20 true-positive (6%), 24 rescue (7%; rescue rate 55%), 29 false-positive, 2 false-negative, and 263 true-negative patients, resulting in a sensitivity of 91% and specificity of 90%. The most common TcMEP alert timing was during tumor resection (96% vs. 91%), and suspension surgeries with or without intravenous steroid administration were performed as intervention techniques. CONCLUSIONS: Postoperative MD rates in IMSCT and EMSCT surgeries using TcMEP monitoring were 25% and 6%, and rescue rates were 29% and 55%. We believe that the usage of TcMEP monitoring and appropriate intervention techniques during SCT surgeries might have predicted and prevented the occurrence of intraoperative MDs.

Stretched intradural extramedullary tanycytic ependymoma of the thoracic spine.

Background: Tanycytic ependymoma is a rare variant of ependymoma that commonly affects the cervical and thoracic spinal cord. It usually arises as intramedullary lesions and extramedullary cases are extremely rare. Case Description: We present a 77-year-old woman with the complaints of a 2-year history of progressive paraparesis and sensory loss in her lower extremities. Magnetic resonance imaging revealed a stretched and fusiform intradural extramedullary lesion at T5-T10 level. Gross total removal of the tumor was achieved and a definitive diagnosis of tanycytic ependymoma was established. Conclusion: This case thus represents a rare case of thoracic intradural extramedullary tanycytic ependymoma and, to the best of our knowledge, it represents the longest intradural extramedullary tanycytic ependymoma in craniocaudal direction ever reported in the literature.

Safety and Feasibility of Augmented Reality Assistance in Minimally Invasive and Open Resection of Benign Intradural Extramedullary Tumors.

OBJECTIVE: Surgical resection of benign intradural extramedullary tumors (BIETs) is effective for appropriately selected patients. Minimally invasive surgical (MIS) techniques have been described for successful resection of BIET while minimizing soft tissue injury. Augmented reality (AR) is a promising new technology that can accurately allow for intraoperative localization from skin through the intradural compartment. We present a case series evaluating the timing, steps, and accuracy at which this technology is able to enhance BIET resection. METHODS: A protocol for MIS and open AR-guided BIET resection was developed and applied to determine the feasibility. The tumor is marked on diagnostic magnetic resonance imaging (MRI) using AR software. Intraoperatively, the planning MRI is fused with the intraoperative computed tomography. The position and size of the tumor is projected into the surgical microscope and directly into the surgeon's field of view. Intraoperative orientation is performed exclusively via navigation and AR projection. Demographic and perioperative factors were collected. RESULTS: Eight patients were enrolled. The average operative time for MIS cases was 128 ± 8 minutes and for open cases 206 ± 55 minutes. The estimated intraoperative blood loss was 97 ± 77 mL in MIS and 240 ± 206 mL in open procedures. AR tumor location and margins were considered sufficiently precise by the surgeon in every case. Neither correction of the approach trajectory nor ultrasound assistance to localize the tumor were necessary in any case. No intraoperative complications were observed. CONCLUSION: Current findings suggest that AR may be a feasible technique for tumor localization in the MIS and open resection of benign spinal extramedullary tumors.

Analysis of characteristics and surgical outcome of intradural extramedullary tumors - a retrospective cohort study of 52 patients.

INTRODUCTION: Although intradural extramedullary tumors (IET) are relatively well studied, research on the typical epidemiological, demographic, and clinical characteristics of these malignancies is scanty. AIM: The aim of this study was to investigate retrospectively the epidemiology, demographics, clinical presentation, imaging data, type of surgery, and the outcome of treatment of IETs. MATERIALS AND METHODS: We performed retrospective chart review of medical history, clinical presentation, paraclinical and imaging data, and operative protocols of operated patients with IETs from January 2011 to August 2020. Special attention was paid to the onset of symptoms, clinical presentation at admission, imaging data, localization, type of surgery, histology, and outcome of the disease. The degree of neurological deficit and disability of the patients at admission, discharge, and follow-up was assessed by the Modified McCormick Scale and the Modified Rankin Scale, respectively. The follow-up period varied from 1 to 105 months (mean 43 months). RESULTS: Fifty-two patients (mean age 58 years, range 14-78 years) with IETs were surgically treated for the study period. At admission to the clinic, 48 patients (92.3%) had vertebralgia, 34 (65.4%) had concurrent radicular pain, 42 (80.8%) had motor deficit, and 18 (34.6%) had sphincter disorders. Total tumor removal was achieved in 47 patients (90.4%). Favourable outcome was registered in 43 patients (82.7%). The degree of disability (mRS) at admission (p=0.0001), the McCormick grade at admission (p=0.0001), gender (p=0.042), and age (p=0.047) of patients were significantly correlated with the functional status assessed by McCormick scale at discharge. CONCLUSIONS: Most of the IETs can be successfully removed via a standard posterior or posterolateral surgical access. Favourable outcome of treatment depends on early diagnosis and total tumor resection.

Monitoring spinal surgery for extramedullary tumors and fractures.

Meningiomas are the most common intradural extramedullary tumors, followed by nerve sheath tumors that can also grow extradurally. Metastases are the most frequent extradural tumors and most commonly affect the thoracic vertebrae. Spinal fractures with column dislocation and/or instability require surgical fixation. Spine surgery for an extramedullary tumor or fracture usually involves decompression of neural elements and instrumentation for stabilization. These procedures risk spinal cord and nerve root injury. The incidence of nerve root deficits after resection of nerve sheath tumors is particularly high since the tumor grows from the rootlets. Intraoperative neurophysiologic monitoring and mapping techniques have been introduced to prevent iatrogenic neurologic deficits. These include motor and sensory evoked potentials, electromyography, compound muscle action potentials, and the bulbocavernosus reflex. The combination of techniques chosen for a particular procedure depends on the surgical level and the character of the lesion.

Extramedullary Acute Leukemia-Still an Unforeseen Presentation.

Myeloid sarcomas (MS) are rare extramedullary (EM) hematological tumors that generally arise during the natural course of acute myeloid leukemia (AML), occurring concomitantly with the onset of systemic leukemia; it can also occur following onset but rarely before. Common sites of EM involvement include the lymph nodes, skin, soft tissue, bone and peritoneum. Herein, we report the case of a 63-year-old man who presented EM AML upon initial diagnosis involving the bone marrow, lymph nodes and skin (leukemia cutis). A diagnosis was made based on immunohistochemistry (IHC). This case presents a diagnostic dilemma due to its atypical presentation and the sites involved. It also highlights the importance of IHC in the diagnosis of EM AML. The potential role of hypomethylating agents and Venetoclax in cases not eligible for hematopoietic stem cell transplant are also discussed.

Laminectomy Versus Laminectomy with Fusion for Intradural Extramedullary Tumors: A Systematic Review and Meta-Analysis.

OBJECTIVE: The primary objective of our systematic review and meta-analysis was to systematically compare the reported outcomes between laminectomy and laminectomy with fixation/fusion (LF) for the treatment of intradural extramedullary tumors (IDEMTs). Our secondary objective was to compare the outcomes between different laminectomy exposure techniques. METHODS: PubMed and Embase were queried for literature on laminectomy and LF for IDEMTs. Reports of transforaminal approaches, interlaminar approaches, corpectomy, pediatrics patients, intramedullary tumors, technical studies, animal or cadaver studies, and literature reviews were excluded. The outcome measures recorded were pain, neurologic function, functional independence, cerebrospinal fluid leak, and wound infection. Where possible, the laminectomy technique (partial laminectomy [PL] vs. total laminectomy [TL]) was specified. Stata, version 17, was used for the fixed effects inverse variance meta-analysis. RESULTS: Of 1849 reports assessed, 17 were included. The meta-analysis revealed that laminectomy (PL or TL) resulted in higher rates of postoperative sagittal instability compared with LF (odds ratio, 1.81; P < 0.001). No differences in any other postoperative outcome were observed between laminectomy and LF (P = 0.44). The systematic review also revealed no differences in postoperative pain, neurologic function, or functional independence or disability between PL and TL. Some evidence suggested that TL might result in greater rates of sagittal instability compared with PL. CONCLUSIONS: No differences between LF, PL, or TL in pain, neurologic deficit, functional independence, cerebrospinal fluid leak, or wound infection were reported. Laminectomy had greater odds of sagittal instability compared with LF. Patients with preoperative sagittal instability requiring extensive removal of the posterior spinal column to achieve adequate resection of large tumors might benefit from LF.

[Intraoperative ultrasound-assisted surgery of spinal tumors]. / Khirurgiya spinal'nykh opukholei s ispol'zovaniem intraoperatsionnogo ul'trazvukovogo issledovaniya.

OBJECTIVE: To improve technique of intraoperative ultrasound-assisted microsurgery of spinal tumors. MATERIAL AND METHODS: There were 68 patients with 70 spinal tumors who underwent intraoperative ultrasound-assisted resection between 2007 and 2018. Age of patients varied from 21 to 80 (mean 48.5±14.3). Intradural tumors were diagnosed in 54 (79.4%) patients (of them intramedullary in 16 (23.5%) and extramedullary in 38 (55.9%) cases). Fourteen patients (20.6%) had extradural tumors. Intraoperative ultrasound was used to determine localization, margins and structure of tumors, interrelations with neural structures, zones of dura opening and myelotomy. We also assessed quality of resection and spinal decompression. RESULTS: In surgery of spinal tumors, intraoperative ultrasound allows to localize the tumor with 95.3% sensitivity, determine the character of its growth, shape, size and internal structure. One can also differentiate the margins of neoplasm, control accuracy of approach, select the optimal zone for dura opening and myelotomy, objectively assess spinal cord and nerve roots decompression in real-time mode. Quality of intraoperative ultrasonography images is comparable to preoperative MRI, and even exceed resolution of MR scans in some cases. CONCLUSION: In our study, intraoperative ultrasound has proven to be a method complementing preoperative CT and MRI. This approach provides additional data in real-time mode to form a complete picture of surgical area, increase accuracy of manipulations and reduce surgical trauma.