Spinal Schwannoma Case Series

All adult patients surgically treated for spinal schwannoma between 2006 and 2020 were eligible for inclusion. Medical records and imaging data were retrospectively reviewed. The primary outcome measures were neurological improvement according to the modified McCormick Scale (mMC) and changes in motor deficit, sensory deficit, gait disturbance, bladder dysfunction, and pain at long-term follow-up. In total, 180 patients with a median follow-up time of 4.4 years were included. Pain was the most common presenting symptom (87%). The median time between symptom presentation and surgery was 12 months, while the median time between diagnosis (first MRI) and surgery was 3 months. Gross total resection (GTR) was achieved in 150 (83%) patients and the nerve root could be preserved in 133 (74%) patients. A postoperative complication occurred in 10 patients (5.6%). There were significant postoperative improvements in terms of motor, sensory, gait, and bladder functions, as well as pain (p < 0.001). Of these symptoms, bladder dysfunction was the one most often improved, with complete symptom resolution in all cases. However, no other predictors of improvement could be identified. There were three cases of recurrence after GTR and nine cases of regrowth after STR. Reoperation was performed in six (3.3%) cases. GTR was associated with a significant improvement in neurological status at long-term follow-up and increased the chance of progression-free survival ¹⁾.

From 1951 to 2010, 367 patients overall were treated. Diagnosis was obtained using angiography and/or myelography (pre-CT era), MRI, or CT scan. A posterior spinal approach was used for most patients; complex approaches were adopted for treatment of giant/dumbbell tumors. A trend of neurophysiology monitoring decreasing the rate of post-op neurological deficits was observed but was not statistically significant enough to draft evidence-based conclusions.

Clinical and radiological assessment of spinal schwannomas has markedly changed over the course of 50 years. Diagnostic tools have improved, and detection of recurrence has become way more sensitive. Neurophysiologic monitoring has become a useful intraoperative tool to guide resection and prevent post-op neurological impairment ²⁾.

82 male and female patients with non-syndromic spinal schwannomas. All patient data were retrospectively collected from the hospital records. As a routine procedure, after admittance and primary evaluation, patients' tumors were classified using CT or MRI in accordance with a proposed classification method, which employs a dual designation method with tree groups (A, B, and C) for tumor volume and four types (I, II, III, and IV) for tumor localization. Subsequent resection surgery was followed by neurological assessments and follow-up at the 45th, 180th, and 360th postoperative days. Along with Karnofsky's performance status scale, pain, sensory deficits, and motor weakness were scored to assess neurologic recovery. Our finding indicates that patients with different tumor types significantly differ in their neurological scores and show consistent but differential neurological recovery at early and late time points post surgery. Complications during and post-surgery were minimal, occurring only in two patients. Our findings further reinforce the established safety of total resection operations and indicate that our proposed classification is a simple, effective tool that has proven helpful in preoperative planning and avoiding unnecessary surgical approaches ³⁾.

48 patients (22 males and 26 females) with spinal schwannoma who were classified into three subgroups: iso/homo, high/rim, and hetero/hetero, based on T2WI/contrast T1WI. A retrospective analysis of tumor size and MIB-1 index was performed in the context of these MRI findings. Intraoperative findings and pre-and postoperative motor performance were also examined.

The average tumor size was 32.4 mm (range 10-130 mm) and the average MIB-1 index was 3.8% (range 1-12). In the three subgroups, there were no significant differences in sex, age, duration of disease, tumor lesion, and dumbbell type. In the hetero/hetero group, the tumor size was significantly greater and the MIB-1 index was significantly higher (both P < 0.05), than the other two groups. The tumor adherence rate was significantly higher for hetero tumors (P < 0.05) and preoperative paralysis was more common in cases with tumor adhesion. The rate of paralysis improvement at 1 month was significantly lower for hetero tumors, but all cases had improved at 6 months.

Contrast T1WI MRI was useful for the prediction of the proliferative activity and growth of spinal schwannomas, which are associated with increased tumor size and adhesion. A heterogeneous pattern on contrast T1WI indicated an increase in size and adhesion of the tumor. This pattern reflected the preoperative motor status and postoperative motor recovery ⁴⁾.

Thirty-two patients with giant spinal schwannomas underwent surgery between September 1998 and May 2013. Tumor size ranged from 2.5 cm to 14.6 cm with a median size of 5.8 cm. There were 9 females (28.1%) and 23 males (71.9%), and the median age was 47 years (range 23-83 years). The median follow-up duration was 36.0 months (range 12.2-132.4 months). Three patients (9.4%) experienced recurrence and required further treatment. All recurrences developed following subtotal resection (STR) of cellular or melanotic schwannoma. There were 3 melanotic (9.4%) and 6 cellular (18.8%) schwannomas included in this study. Among these histological variants, a 33.3% recurrence rate was noted. In 1 case of melanotic schwannoma, malignant transformation occurred. No recurrence occurred following gross-total resection (GTR) or when a fibrous capsule remained due to its adherence to functional nerve roots.

Resection is the treatment of choice for symptomatic or growing giant schwannomas, frequently requiring anterior or combined approaches, with the goals of symptom relief and prevention of recurrence. In this series, tumors that underwent GTR, or where only the capsule remained, did not recur. Only melanotic and cellular schwannomas that underwent STR recurred ⁵⁾.

Consecutive 49 patients with intradural extramedullary (IDEM) schwannoma were surgically resected: 31 patients via MIS approach (MIS group), 6 patients via muscle-splitting using tubular retractor, and 25 patients via unilateral hemilaminectomy preserving the contralateral paraspinal muscle. Eighteen patients underwent total laminectomy (TL group). Medical record including perioperative data and radiologic data were reviewed.

On the initial magnetic resonance image, the mean maximal sagittal diameter of the tumor was 23.9 mm and 26.9 mm, and mean maximal axial diameter was 16.1 mm and 22.8 mm in MIS and TL groups, respectively (p=0.452 and p=0.011, respectively). The foraminal extension of the tumor was identified in 8 in MIS and 9 in TL group (p=0.081). The tumor location involved was mostly observed in 20 lumbar spines in MIS group and 17 cervicothoracic spines in TL group (p=0.001). Intraoperatively, all tumors in MIS group could be totally resected with reduced operative time and blood loss. During the follow-up period of 38.2 months and 51.2 months in the MIS and TL group, the clinical improvement was not different between the surgical approaches (p=0.332).

Safe and complete resection of IDEM schwannoma was obtained through MIS approach. Regardless of sagittal extension of tumor, axial diameter within 16 mm-sized schwannomas located at the lumbar spine could be an effective indication for MIS approach even for foraminal extension ⁶⁾.

Conti et al., present a series of 179 spinal neurinomas consecutively observed at the Department of Neurosurgery at the University of Florence for a period of 30 years (between 1967 and 1997). We decided to limit the retrospective study to obtain at least 5 years of follow-up. Therefore, 20 additional neurinomas treated between 1997 and 2002 were excluded.

All the cases are evaluated under statistical, clinical, neuroradiological, and surgically technical profiles based on data from clinical records and from periodic check-ups after surgery. In particular, the results are analyzed on the basis of an accurate pre- and postsurgical evaluation using Karnofsky's scale and Kleklamp-Samii's scoring system.

We treated 179 spinal neurinomas in 152 (93 male and 59 female) patients. The mean age was 44.3. In 33 cases the neurinoma was sited in the cervical tract, in 59 cases in the dorsal tract, and in 87 cases in the lumbo-sacral tract. Eleven patients harbored Recklinghausen's neurofibromatosis (7 NF1 and 4 NF2 of which 1 was intramedullary). In 123 cases the neurinoma was intradural, in 11 cases it was extradural, in 2 intra/extradural, in 9 it had a dumbbell form, and in 2 cases it was intramedullary; the remaining cases had neurofibromatosis. The most common presurgical symptom was segmental pain. Total removal of the lesion was possible in the first operation for 174 neurinomas. We encountered 3 cases of malignant neurinoma of which 1 was in NF2. The result of surgery was recovery in 108 cases; 2 patients with NF2 died, and local recurrence occurred even after total exeresis (excision) and radiotherapy in the cases of malignant neurinoma.

Schwannomas represent the most frequent tumor lesions of the spine with prevalence for the cervical-inferior tract and the dorso-lumbar passage. Intramedullary neurinomas are rarely observed. The total surgical removal of neurinomas is often an attainable goal, and clinical improvement is the common outcome with exception to malignant forms and NF2 neurofibromatosis. We describe a series of 179 treated schwannomas ⁷⁾.

Are spinal schwannomas as benign as we think? To what extent do patients recover? Are patients prone to develop late complications such as cystic myelopathy or symptomatic spinal deformity? Is their life expectancy compromised? In an effort to answer these questions, the authors analyzed the long-term outcome for 187 patients from one neurosurgical department with surgically treated spinal schwannoma. Median follow-up period was 12.9 years (2454 patient years). One-fifth of the patients considered themselves free of symptoms at follow-up examination. The most common late complaint was local pain (46%), followed by radiating pain (43%), paraparesis (31%), radicular deficit (28%), sensory deficit due to a spinal cord lesion (27%), and difficulty voiding (19%). Late complications occurred in 21% of the patient population, including cystic myelopathy (2%), spinal arachnoiditis (6%), spinal deformity (6%), and troublesome pain (7%). Life expectancy of the patients corresponded to that of the general population ⁸⁾.