Melanotic Schwannoma of the Cervical Spine Progressing With Pulmonary Metastasis: Case Report

Melanotic schwannoma (MS) is an unusual variant of nerve sheath neoplasm. Only 10% of these tumors will undergo malignant degeneration, with exceedingly rare reported metastasis. We present a 32-year-old woman with a 6-month history of cervical pain and left arm progressive weakness. Neurological examination showed a left upper limb radicular pain, with pyramidal syndrome at C5 level. The magnetic resonance imaging (MRI) study highlighted an intradural extramedullary heterogeneous mass along the spinal cord at the C4–C5 level, slightly hyperintense with T₁ and hypointense with T2-weighted sequences, invading the left neural foramen. The patient underwent C3–C5 laminectomy with total resection of a black tumor. In the postoperative period, a patent deficit of shoulder abduction ensued related to the nervous section. Microscopically, compactly fascicles of spindle-shaped cells with pleomorphic and hypercromatic nuclei, dark brown intracellular pigments, as well as some mitotic figures were seen. Immunohistochemical stains for S-100, Human Melanoma Black-45 (HMB-45), and vimentin were positive, with Ki-67 labelling index (LI) of 15% compatible with MS. Six months after radiotherapy she presents local recurrence and lung metastatic dissemination of the MS. She underwent left pulmonary segmentectomy, followed by chemotherapy and radiosurgery. The patient developed a febrile neutropenia and worsening of general status, and died after 3 months due to respiratory complications. MS are rare tumors with potential for local recurrence and distal metastasis. Complete surgical resection remains as the treatment of choice, once the uncommon cases with malignant progression shows low response to chemo and radiotherapy.     

Surgical Management of Spinal Intramedullary Tumors: Radical and Safe Strategy for Benign Tumors

Surgery for spinal intramedullary tumors remains one of the major challenges for neurosurgeons, due to their relative infrequency, unknown natural history, and surgical difficulty. We are sure that safe and precise resection of spinal intramedullary tumors, particularly encapsulated benign tumors, can result in acceptable or satisfactory postoperative outcomes. General surgical concepts and strategies, technical consideration, and functional outcomes after surgery are discussed with illustrative cases of spinal intramedullary benign tumors such as ependymoma, cavernous malformation, and hemangioblastoma. Selection of a posterior median sulcus, posterolateral sulcus, or direct transpial approach was determined based on the preoperative imaging diagnosis and careful inspection of the spinal cord surface. Tumor-cord interface was meticulously delineated in cases of benign encapsulated tumors. Our retrospective functional analysis of 24 consecutive cases of spinal intramedullary ependymoma followed for at least 6 months postoperatively demonstrated a mean grade on the modified McCormick functional schema of 1.8 before surgery, deteriorating significantly to 2.6 early after surgery (< 1 month after surgery), and finally returning to 1.7 in the late postoperative period (> 6 months after surgery). The risk of functional deterioration after surgery should be taken into serious consideration. Functional deterioration after surgery, including neuropathic pain even long after surgery, significantly affects patient quality of life. Better balance between tumor control and functional preservation can be achieved not only by the surgical technique or expertise, but also by intraoperative neurophysiological monitoring, vascular image guidance, and postoperative supportive care. Quality of life after surgery should inarguably be given top priority.     

Specialized Respiratory Management for Acute Cervical Spinal Cord Injury:: A Retrospective Analysis

Background:

In individuals with cervical spinal cord injury (SCI), respiratory complications arise within hours to days of injury. Paralysis of the respiratory muscles predisposes the patient toward respiratory failure. Respiratory complications after cervical SCI include hypoventilation, hypercapnea, reduction in surfactant production, mucus plugging, atelectasis, and pneumonia. Ultimately, the patient must use increased work to breathe, which results in respiratory fatigue and may eventually require intubation for mechanical ventilation. Without specialized respiratory management for individuals with tetraplegia, recurrent pneumonias, bronchoscopies, and difficulty in maintaining a stable respiratory status will persist.

Objective:

This retrospective analysis examined the effectiveness of specialized respiratory management utilized in a regional SCI center.

Methods:

Individuals with C1-C4 SCI (N = 24) were the focus of this study as these neurological levels present with the most complicated respiratory status.

Results:

All of the study patients’ respiratory status improved with the specialized respiratory management administered in the SCI specialty unit. For a majority of these patients, respiratory improvements were noted within 1 week of admission to our SCI unit.

Conclusion:

Utilization of high tidal volume ventilation, high frequency percussive ventilation, and mechanical insufflation– exsufflation have demonstrated efficacy in stabilizing the respiratory status of these individuals. Optimizing respiratory status enables the patients to participate in rehabilitation therapies, allows for the opportunity to vocalize, and results in fewer days on mechanical ventilation for patients who are weanable.     

Frequency of Diplopia after Intraoperative Nerve Disturbance in Trochlear Nerve Schwannoma: A Case Report and Systematic Review

Schwannomas of the trochlear nerve are relatively rare, and most patients present with preoperative diplopia because of trochlear nerve palsy. We describe the case of a 61-year-old male patient with a trochlear nerve schwannoma and no pre- and postoperative diplopia, despite his trochlear nerve being cut during the operation. We aimed to investigate the frequency of postoperative diplopia associated with intraoperative trochlear nerve disturbance by reviewing previous case reports, wherein postoperative diplopia did not occur after the trochlear nerve was cut intraoperatively. We recorded the frequency of diplopia because of intraoperative trochlear nerve disturbance, such as the trochlear nerve being cut, in cases without pre- and postoperative diplopia. We searched the PubMed, Medline, and Google Scholar databases for works published from 1976 to 2020 and followed the preferred reporting items for systematic reviews and meta-analyses guidelines. We reviewed 36 publications and found 92 cases of trochlear nerve schwannoma. Surgical resection was performed for 43 patients, of whom 40 were kept under observation and 9 were treated with radiation therapy. Of the 43 cases, 9 without preoperative diplopia underwent gross total resection. We analyzed ten cases (including ours) without preoperative diplopia to check for postoperative diplopia. In total, four cases, including ours, did not display postoperative diplopia despite the trochlear nerve being cut. This may be attributed to the preoperatively acquired motor and sensory fusion in the patient’s vision because of tumor progression. Our findings may benefit neurosurgeons who treat patients with schwannomas and help them predict patients’ outcomes.     

Clinical Relevance of Pathological Grades of Malignant Peripheral Nerve Sheath Tumor: A Multi-Institution TMTS Study of 56 Cases in Northern Japan

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is a relatively rare soft tissue tumor, and its clinical relevance of pathological grades remains obscure. METHODS: Fifty-six cases of MPNST identified from the files of seven oncology centers of the Tohoku Musculoskeletal Tumor Society (TMTS) and National Cancer Center were analyzed for histologic grades, demographics, treatments, and prognostic factors. The average follow-up period was 41 months. RESULTS: Twenty-two men and 34 women with a mean age of 45 years were involved. Forty-four (78.6%) of 56 tumors were in the lower extremity or trunk. Fifty tumors (89%) were classified as high grade, and the remaining six as low grade. Twenty-one (39.6%) of 53 patients who underwent tumor excision developed local recurrences. An axial site and inadequate surgical margin were defined as risk factors for local recurrence. The overall survival rates of the 56 patients were 55.1% at 3 years and 43.3% at 5 years. Univariate analysis of the 56 patients revealed large-sized tumors, metastasis at presentation, and histologically high grade were significantly associated with poor prognosis. Multivariate analysis revealed a large tumor and metastasis at presentation to be independent prognostic factors. CONCLUSIONS: The current study involving 56 patients with MPNST showed the aggressive clinical behavior of the tumor. Large-sized tumors, metastasis at presentation, and high histological grade were related to poor prognosis on univariate analysis, but independency of histological grade was still obscure. In the treatment for a large and high-grade MPNST, an alternative strategy should be further considered.     

Sciatic Neuropathy: Case Report and Discussion of the Literature on Postoperative Sciatic Neuropathy and Sciatic Nerve Tumors

Sciatic nerve injury and dysfunction is not an uncommon cause of lower extremity symptoms in a musculoskeletal practice. We present the case of a man who presented with lower extremity weakness, pain, and cramps, and was initially diagnosed at an outside institution with bilateral S1 radiculopathies and recommended for spine surgery. He came to us for a second opinion. Electrodiagnostic testing revealed an isolated sciatic neuropathy and the patient was referred for imaging, which showed a sciatic nerve sheath tumor. Review of the literature on sciatic neuropathies shows that there can be many possible etiologies of sciatic nerve dysfunction, but that hip arthroplasty continues to be the leading risk factor. Sciatic nerve tumors are not commonly described in the literature and their definitive management remains unclear.     

Malignant peripheral nerve sheath tumors of the head and neck: management of 10 cases and literature review

BACKGROUND: This study analyzes the management and outcomes of a series of 10 malignant peripheral nerve sheath tumors (MPNST) of the head and neck. METHODS: From 1984 to 2004, 10 patients underwent surgical treatment of a MPNST. We retrospectively reviewed presenting symptoms, radiological findings, surgical management, and follow-up status and performed a literature review. RESULTS: Eight tumors were located at the lateral skull base; 2 involved the vagus nerve in isolation. Two lesions were growing within the sinonasal tract. The most common presenting symptom was a rapidly enlarging cervical mass. Seventy percent of the tumors could be resected completely. Long-term follow-up showed a 2-year disease-specific survival rate of 50% and 5-year survival rate of 20%. Negative prognostic indicators were advanced tumor stage, early recurrence, and presumably also the presence of von Recklinghausen's disease. Postoperative adjuvant radiotherapy was found to make no difference in outcome. CONCLUSIONS: Although rare, MPNST is one of the most aggressive tumors in the head and neck area. Complete tumor removal is the mainstay of treatment and most important prognostic factor of MPNST. Adjuvant radiotherapy should be used to assist surgical excision in local control. The role of adjuvant chemotherapy remains controversial.     

Peripheral Nerve Schwannoma: A Review of Varying Clinical Presentations and Imaging Findings

A schwannoma or neurilemmoma is a benign, isolated, noninvasive, and encapsulated tumor originating from Schwann cells of the peripheral nerve sheath. The incidence of a schwannoma occurring in the foot and ankle is rare, with prevalence rate of 1% to 10%. Schwannomas have no sex predilection, and they commonly occur in patients in their fourth decade. Malignant transformation of benign schwannoma is unusual; however, it is important to note that malignant variants of schwannomas do exist and account for about 5% to 10% of all soft tissue sarcomas. We present 3 cases of benign schwannoma in the lower extremity. All 3 patients presented with varying clinical symptoms, including pain, paresthesia, weakness, and a palpable mass. A schwannoma was eventually diagnosed in all 3 patients. We discuss and review the known entities of peripheral nerve schwannoma and describe the clinical and imaging findings and therapeutic strategies for treating and diagnosing peripheral nerve schwannoma.     

自体和异体神经组织联合移植修复脊髓损伤的实验研究

目的：探讨神经组织联合移植对成鼠急性脊髓损伤的修复能力。方法：成年雌性Ｗｉｓｔａｒ鼠３６只随机分为３组,损伤Ｔ１－３脊髓左后柱,移植孕１４ｄ胚胎脊髓（ＦＳＣ组１５只）或带血管正中神经加胚胎脊髓（Ｖ＋Ｆ组１５只）,另６只做对照组。术后８周行体感诱发电位、光、电镜和免疫组化检查。结果：Ｖ＋Ｆ组胚胎组织体积增长速度、神经纤维和神经元数目显著高于ＦＳＣ组（Ｐ〈０．０１）,细胞大多分化较好,有少数类似运动神     

Cervical Lift-up Basket Laminoplasty after Resection of Spinal Intramedullary Tumors: A Finite Element Analysis and Clinical Image Evaluation

Although reconstructive laminoplasty is commonly performed after resection of spinal intramedullary tumors of the cervical spine, its biomechanical rigidity of laminoplasty framework remains unclear. The objective of this study was to examine the structural reliability of our unique method of cervical lift-up basket laminoplasty by using computed tomography (CT)-based finite element analysis (FEA) and clinical radiological evaluation. A finite element model of cervical laminoplasty was created based on CT images using FEA software. Cervical lift-up basket laminoplasty (Basket) was compared with the standard style of open-door basket laminoplasty (Open-door). Clinical subjects for radiological evaluation comprised 33 patients who underwent cervical lift-up basket laminoplasty after resection of spinal intramedullary tumors. An FEA-equivalent stress histogram showed that stress was moderately dispersed around the basket. Virtual displacement of the spinous process of the Basket model was equivalent to that of the Open-door model in any direction of posterior-to-anterior, right-to-left, or top-to-bottom force. In the clinical analysis, radiological data with a minimum postoperative period of 6 months were obtained in a total of 28 out of 33 patients. No patients underwent revision surgery because of implant-related complications. No significant differences in C2-C7 angle or cervical tilt angle were observed between pre- and postoperatively. The structural rigidity of cervical lift-up basket laminoplasty was equivalent to the open-door style on the FEA. Clinical radiological evaluation suggested that there were no serious adverse events associated with cervical laminoplasty, although the longer postoperative follow-up is mandatory.     

Nerve Sheath Myxoma (Neurothekeoma) of the Gingiva,A Case Report and Review of the Literature

Nerve sheath myxoma (NSM) is a benign peripheral nerve sheath tumor that rarely occurs in the oral cavity. Among the 23 reported intraoral cases, no lesion has previously been reported on the gingiva. In this report, we describe the first gingival case of oral neurothekeoma with histopathologic and immunohistochemical characteristics. The patient, a 32 year old female presented with a slowly growing gingival mass diagnosed clinically as an epulis. The lesion was surgically excised. Histopathologically, the lesion presented as a submucosal multinodular mass composed of spindle and stellate-shaped cells with a myxoid background. Immunohistochemically, the tumor cells were sporadically positive for S-100 and NSE and negative for GFAP, EMA, SMA, CD68 and HMB45. The immunoprofile of this lesion confirmed a Schwann cell origin. The lesion was followed up for 10 months with no reports of recurrence.     

Orbit Solitary Fibrous Tumor: A Proposed Risk Prediction Model Based on a Case Series and Comprehensive Literature Review

Solitary fibrous tumors (SFTs) of the orbit are rare. In order to further characterize the clinical and pathologic features of solitary fibrous tumor arising at this anatomic site, 12 cases of orbital SFTs were analyzed in conjunction with a review of 263 cases reported from the English literature in order to develop a risk prediction model. SFTs of the orbit were equally distributed between males (n = 5) and females (n = 7) with a mean patient age of 46.8 years (median 44.5 years; range 18–76 years) at initial diagnosis. The patients typically presented with swelling or mass around the orbit, with proptosis (n = 10), ptosis (n = 5), and visual changes (n = 6). Tumors were orbital (n = 10) or upper eyelid (n = 2). Mean tumor size was 2.5 cm (median 2.6 cm). Microscopically, the tumors were characterized by cytologically bland spindle cells with patternless growth, hypocellular and hypercellular areas, variable amounts of collagen, and ectatic, branching blood vessels. By immunohistochemistry, all cases had a strong nuclear STAT6 expression. All patients were initially managed with excision or biopsy, three with presurgical embolization. The two patients with biopsy only had persistent disease (mean 37.2 months), but a third patient developed distant bone metastasis at 86.9 months. Overall mean follow-up was 73.1 months: 9 patients are alive or dead without disease (mean 77.9 months), two patients with persistent disease, and one patient with metastatic disease at last follow-up (102 months). Incorporating cases sufficiently reported in the literature, a risk prediction model based on age > 45 years, tumor size > 3 cm, tumor necrosis, mitoses of > 4/2 mm², moderate to high cellularity, and moderate to severe pleomorphism allows for risk stratification for the development of local recurrence and distant metastasis. In conclusion, orbital SFTs are rare, but can be reliably diagnosed based on the presence of characteristic morphologic features and STAT6 immunohistochemistry. Orbital tumors tend to show a higher frequency of local recurrence than distant metastasis, which can be predicted by a risk stratification model unique to orbital tumors. With late disease common, long term clinical follow-up is recommended.     

Intraoperative ultrasound imaging of the spinal cord: Syringomyelia, cysts, and tumors — A preliminary report

Dynamic intraoperative imaging of the spinal cord was done using a real-time ultrasound scanner. Prior to opening the dura mater the neurosurgeon is able to “explore” the intradural space and with a 7.5 MHz transducer visualize the normal spinal cord, including the central canal and the dentate ligaments. Anterior and posterior spinal arteries may be seen in certain patients. In syringomyelia the fluid-filled cavities may be visualized with ultrasound and drained or shunted with intraoperative ultrasound guidance. Spinal cord cysts or cystic components of tumors can be precisely identified and drained using ultrasound. Intramedullary tumors can be demonstrated sonographically, as can the location and extent of intradural extramedullary tumors and tumors that have both extradural and intradural components. Experience to date with intraoperative imaging of the spinal cord and with the real-time ultrasound scanner is very encouraging, and in the future it should allow for a more precise characterization of and operative approach to lesions of the spinal cord.     

Subarachnoid Hematoma of the Craniocervical Junction and Upper Cervical Spine After Traumatic Cerebral Contusion: Case Report

Spinal subarachnoid hematoma (SSH) is a rare condition, more commonly occurring after lumbar puncture for diagnostic or anesthesiological procedures. It has also been observed after traumatic events, in patients under anticoagulation therapy or in case of arteriovenous malformation rupture. In a very small number of cases no causative agent can be identified and a diagnosis of spontaneous SSH is established. The lumbar and thoracic spine are the most frequently involved segments and only seven cases of cervical spine SSH have been described until now. Differential diagnosis between subdural and subarachnoid hematoma is complex because the common neuroradiological investigations, including a magnetic resonance imaging (MRI), are not enough sensitive to exactly define clot location. Actually, confirmation of the subarachnoid location of bleeding is obtained at surgery, which is necessary to resolve the fast and sometimes dramatic evolution of clinical symptoms. Nonetheless, there are occasional reports on successful conservative treatment of these lesions. We present a peculiar case of subarachnoid hematoma of the craniocervical junction, developing after the rupture of a right temporal lobe contusion within the adjacent arachnoidal spaces and the following clot migration along the right lateral aspect of the foramen magnum and the upper cervical spine, causing severe neurological impairment. After surgical removal of the hematoma, significant symptom improvement was observed.