A case report of giant malignant schwannoma of the sciatic nerve associated with neurofibromatosis-1: A CARE-compliant article.

RATIONALE: Neurofibromatosis type 1 (NF1) is an autosomal dominant neurocutaneous syndrome that causes multiple central and peripheral nerve sheath tumors. People with NF1 have a 10% chance of developing malignant peripheral nerve sheath tumors (MPNSTs). Here we report a unique instance of a malignant schwannoma that has remained free of metastasis since its initial removal a decade ago. The malign schwannoma has been infrequently documented in the literature, and remarkably, no instances of such an extensive postoperative time without metastases have ever been described. PATIENT CONCERNS: A 46-year-old male patient with NF had multiple neurofibromas in different parts of his body, underwent surgery about 10 years ago (2013), and was diagnosed histopathologically as MPNST. DIAGNOSES: He was admitted to our institution with a recurrent mass in the posterior third of the proximal thigh and severe pain radiating to the left lower extremity, which presented as sciatic pain (2021). A magnetic resonance imaging and fluorodeoxyglucose-positron emission tomography examination revealed that the tumor was likely malignant. INTERVENTIONS: Surgical excision was performed. OUTCOME: A 10-year follow-up revealed no metastases or neurologic impairment. LESSONS: When articles about benign schwannomas are placed in a separate category, little is written about NF-1-related malignant schwannomas of the sciatic nerve. MPNSTs are high-grade, aggressive sarcomas with a high risk of local recurrence (40%-65%) and metastasis to other body parts. Therefore, among the various benign peripheral nerve sheath tumors in NF-1 patients, the diagnosis of MPNST is crucial.Orthopedic surgeons should be aware that neurofibromas in NF-1 have a significant risk of developing MPNSTs. This study reports the successful treatment of a giant malignant sciatic nerve schwannoma with a long follow-up period without metastasis.

Myofibroma mimicking peripheral nerve sheath tumour with ulnar nerve compression symptoms.

We report a case of myofibroma encasing the ulnar nerve on the medial aspect of the left arm with motor and sensory deficit secondary to compression. Initially, the tumour appeared to be a benign peripheral nerve sheath tumour based on preoperative imaging, with clinical examination positive for left hand clawing and a positive Wartenberg's and Froment's sign. However, intraoperative dissection demonstrated that the mass did not originate from the ulnar nerve proper, lowering suspicion for a peripheral nerve sheath tumour. Histopathological analysis showed spindle cell neoplasm, consistent with myofibroma. The patient underwent hand occupational therapy subsequently, with improvement of grip strength from 5 lb to 12 lb by 4 months postoperatively and resolution of clawing of the hand postoperatively. We discuss differentiating features for this rare occurrence of solitary adult myofibroma, where the final diagnosis was only made after formal histopathological analysis.

Post-traumatic glomus tumor of the left anterior supraclavicular nerve: a case report.

OBJECTIVES: Peripheral nerve glomus tumors are extremely rare and occur with typical symptoms of peripheral neuropathic pain. Clinicians hardly consider this entity when faced with the swelling of a peripheral nerve and the diagnosis is reached only with histological examination. Nerves of limbs are usually affected and the solid glomus tumor is the most frequent histological variant. CASE DESCRIPTION: A 55-year-old man presented with a glomus tumor of the anterior supraclavicular nerve of the left cervical plexus, misdiagnosed clinically and radiologically as neuroma. Despite the preoperative suspicion and the intraoperative appearance, the histological examination revealed a glomus tumor with a prevalent muscular component, a glomangiomyoma. Once the tumor was removed, pain regressed completely. CONCLUSIONS: Because of its rarity, pre-operative diagnosis of glomus tumors is still a challenge, especially when arising from peripheral nerves. In the presence of chronic localized neuroma-type pain and sensitivity, glomus tumors should be considered in the pool of differential diagnosis, even if the imaging is not conclusive.

Hemangioblastoma of the Peripheral Nervous System: A Critical Analysis of Its Rarity in Von Hippel-Lindau Disease.

Von Hippel-Lindau (VHL) disease is a multisystem disease cause by germline mutations of the VHL tumor suppressor gene. Hemangioblastomas are the most common manifestation of VHL disease and can occur in the central nervous system in up to 90% of these patients. By contrast, we found only one true case of a peripheral nervous system (PNS) hemangioblastoma in the setting of VHL. We explore the possible reasons behind the lack of PNS hemangioblastomas in VHL disease.

Repetitive syncope caused by a rare massive sporadic malignant peripheral nerve sheath tumor involving carotid arteries: A case report.

RATIONALE: Malignant peripheral nerve sheath tumors (MPNSTs) are rare sarcomas arising from peripheral nerves. MPNSTs are uncommon in the head and neck, and various clinical manifestation often make the diagnosis challenging. PATIENT CONCERNS: A 67-year-old female was referred for evaluation of repetitive syncope with a massive mass in the neck. Preoperative evaluation revealed potential neuroendocrine activity of the mass and enhanced computed tomography showed carotid artery was involved. DIAGNOSIS: According to the preoperative imaging, intraoperative finding and postoperative pathological examination, the diagnosis of left neck MPNST involving left carotid arteries was made. INTERVENTIONS: Volume expansion therapy with phenoxybenzamine started one week before surgery. Complete surgical resection of the mass was performed and pathological analysis suggested the diagnosis of MPNST. The postoperative radiotherapy was not given due to her poor nutrition. OUTCOMES: This patient recovered well after surgery and no sign of recurrence was noted at 2-year follow-up. LESSONS: Though the involvement of carotid artery with neuroendocrine activity is rare in sporadic MPNST, preoperative scanning of blood and urine catecholamine is crucial for intraoperative hemodynamic stability, especially when carotid artery is involved.

Cystic Dumbbell-Shaped C1 Schwannoma with Intracranial Extension and Hydrocephalus.

BACKGROUND: Schwannomas at the craniocervical junction commonly originate from the lower cranial nerves or C1 and C2 nerves. To date, very few cases of C1 schwannomas have been described in the literature, and the majority involve either the intra- or the extradural compartment, but not both. To our knowledge, this report documents the first case of a dumbbell-shaped C1 schwannoma that encompassed both intra- and extradural compartments and was accompanied by hydrocephalus. CASE DESCRIPTION: The patient was admitted to our hospital, where magnetic resonance imaging revealed a tumor at the craniocervical junction, extending from the C1 level of the right first cervical vertebra into the cerebellopontine angle with 2 giant cysts. We removed the tumor by performing a midline posterior craniectomy and cervical laminectomy. Intraoperatively, the tumor was found to originate from the right C1 posterior root. The pathological diagnosis was of a schwannoma. The patient was subsequently discharged without any neurologic deficits. CONCLUSIONS: To our knowledge, we present the first case of a dumbbell-shaped C1 schwannoma with intracranial extensions and accompanying hydrocephalus. The tumor had spread inside and outside the dura, but was safely removed. Our findings in this case emphasize that to achieve safe resection, detailed case-specific preoperative consideration is essential.

Lymphomatosis cerebri with cauda equina lymphoma.

PURPOSE/AIM: Lymphomatosis cerebri (LC) and cauda equina lymphoma are both rare forms of primary central nervous system lymphoma (PCNSL). LC is characterized by diffuse bilateral non-enhancing (or partially enhancing) inltrative lesions without mass effect, which can be easily confused with other forms of leukoencephalopathy and, thus, lead to delays in diagnosis. CASE REPORT: For the first time, a case of LC concomitant with cauda equina involvement confirmed by brain stereotactic biopsy is presented. CONCLUSIONS: This case highlights the necessity of using a multimodal strategy in diagnosing PCNSL, including multimodal magnetic resonance, cerebral spinal fluid cytology, flow cytometry and fluorodeoxyglucose positron emission tomography/computed tomography.

Long-Term Outcomes after Surgical Treatment of Radial Sensory Nerve Neuromas: Patient-Reported Outcomes and Rate of Secondary Surgery.

BACKGROUND: This study aimed to (1) describe long-term patient-reported outcomes of surgically treated symptomatic radial sensory nerve neuromas on function, pain interference, pain intensity, and satisfaction; (2) assess which factors were associated with worse function, higher pain intensity, and more pain interference; and (3) describe the secondary surgery rate and factors associated with secondary surgery. METHODS: The authors conducted a retrospective review of patients surgically treated for radial sensory nerve neuroma from 2002 to 2016 (n = 54). Twenty-five of these 54 patients completed a follow-up survey including the Patient-Reported Outcomes Measurement Information System (PROMIS) upper extremity, pain interference, and depression scales; numerical rating scale pain and satisfaction instruments; and the global rating scale of change, at a mean period of 10.7 ± 4.3 years after neuroma surgery. RESULTS: The mean PROMIS scores were 45.0 ± 12.1 for upper extremity, 55.5 ± 10.3 for pain interference, and 49.9 ± 10.2 for depression, and were within 1 SD of the general population. Eight patients (32 percent) reported symptoms as unchanged or worse following neuroma surgery. The median numerical rating scale pain was 3 (interquartile range, 1 to 6) and the global rating scale of change satisfaction was 10 (interquartile range, 7 to 10). Older patients (p = 0.002) and patients with higher PROMIS pain interference (p < 0.001), higher numerical rating scale for pain (p = 0.012), and lower global rating scale of change scores (p = 0.01) had worse PROMIS upper extremity scores. The secondary surgery rate was 20 percent and was associated with the presence of multiple neuromas (p = 0.001). CONCLUSIONS: Radial sensory nerve neuromas remain difficult to treat. They have a high secondary surgery rate (20 percent), with only 68 percent of patients reporting improvement after surgical intervention. Patient-reported outcomes after surgery are similar to conditions of the general population; however, the range of outcomes is wide.

Radial neuropathy caused by intraneural leiomyoma: A case report.

INTRODUCTION: Leiomyoma of peripheral nerve is a rare condition characterized by neuropathy of affected nerve. We herein report a rare presentation of leiomyoma of radial nerve which presented with wrist drop. PATIENT CONCERNS: A 37-year-old man visited our clinic with a history of sudden onset weakness of the wrist dorsiflexion/finger extension of the right side. DIAGNOSIS: T2-weighted with fat saturation image of MRI demonstrated a well-defined, intra-neural, round mass of about 0.8 cm × 0.5 cm within the radial nerve. Excision of mass established the pathological diagnosis of intra-neural leiomyoma. INTERVENTIONS: The patient underwent excision of mass and attached nerve tissue, followed his medial antebrachial nerve graft for repair of the defected radial nerve. OUTCOMES: As of the 1-year follow-up, no symptoms of recurrence have been observed. Also, the strength of wrist dorsiflexion improved to grade 4/5 CONCLUSION:: This rare case demonstrates the importance of MR imaging to differentiate intra-neural leiomyomas from other benign peripheral nerve sheath tumors. Surgical treatment plays an important role in the treatment of patient with intraneural leiomyoma with neurologic deficits.

Schwannoma of the Intercostal Nerve Manifesting as Chest Pain.

Many different benign and malignant tumors develop in the chest wall and pose a diagnostic and therapeutic challenge to clinicians. Chest wall schwannomas of the intercostal nerve are rare. This report describes the clinical and imaging findings of a patient who presented with persistent and progressive chest pain. The intercostal tumor was treated using wide excision with chest wall reconstruction and titanium plate fixation. Schwannoma was diagnosed on the basis of histopathologic examination.

Primary peripheral nerve tumors associated with nerve-territory herpes zoster.

Herpes viruses have been described as markers of occult cancer and have also been implicated in oncogenesis. This group of viruses includes varicella-zoster virus (VZV) which is well-known for its ability to evade the immune response by lying dormant in the dorsal root ganglion of peripheral nerves. Although it is common knowledge that VZV reactivation causes herpes zoster (shingles), there have been no reports in literature of herpes zoster manifesting in the dermatomal territory of peripheral nerves involved by either benign or malignant tumors. We report two cases of patients with peripheral nerve tumors who presented with herpes zoster in the dermatomal distribution of the involved nerves. One patient had primary neurolymphomatosis, whereas the other had a sacral schwannoma. We believe these are the first cases to be reported that demonstrate herpes zoster at clinical presentation in patients with peripheral nerve tumors. This suggests that VZV may have the potential to cause peripheral nerve tumors via a complex interplay of viral oncogenes and alterations in host immunological responses.

Neuroma.

Neuroma formation occurs because of some degree of nerve injury followed by improper intrinsic nerve repair. The cause of neuroma pain is incompletely understood, but appears to be multifactorial in nature, including local and system changes. A comprehensive understanding of nerve anatomy, injury, and repair techniques should be used when dealing with neuroma formation and its physical manifestations. Diagnosis of neuroma is clinically characterized by pain associated with scar, altered sensation within the given nerve distribution, and a Tinel sign. The pathophysiology of neuroma formation is reviewed.

Malignant peripheral nerve sheath tumor of the sciatic nerve presenting with leg pain in the setting of lumbar scoliosis and spinal stenosis.

STUDY DESIGN: Case report. OBJECTIVE: We present a case of malignant peripheral nerve sheath tumor (MPNST) presenting as neuropathic pain in the setting of lumbar scoliosis and spinal stenosis. Most peripheral nerve sheath tumors are benign, and malignant cases are more commonly associated with neurofibromatosis type 1 or prior radiation exposure. MPNST is a rare tumor with a poor prognosis. We report a case of MPNST that presented as neuropathic pain following lumbar decompression and fusion surgery. METHODS: A 60-year-old woman presented for management of lumbar scoliosis, stenosis, and left leg pain. After lumbar decompression and fusion surgery, the patient was readmitted to the hospital after falling 10 weeks post-op. She reported gradual recurrence of leg pain. Left foot drop was noted on exam. Imaging studies showed no spinal changes postoperatively or residual stenosis. Obesity limited electrodiagnostic studies. Hip MRI revealed a lobular soft tissue mass in the left sciatic notch. Surgical resection and pathology provided the diagnosis of MPNST. The patient declined wide resection and other interventions after seeking a second opinion. Palliative pain management was implemented. RESULTS: The patient expired 15 months after her index spinal surgery. CONCLUSIONS: MPNST is an extremely rare tumor that can present with symptoms similar to radiculitis. Clinical signs and symptoms of MPNST are vague and nonspecific due to compression of surrounding structures. Surgical wide resection is the first line of treatment for MPNST with chemotherapy and radiotherapy as adjuvant treatments. MPNST has a poor prognosis with reported 5-year survival ranging from 16 to 54%. This case demonstrates the need to pursue additional workup when diagnostic imaging and objective findings do not satisfactorily explain the clinical presentation. LEVEL OF EVIDENCE: IV.

Nondiscogenic Sciatica: What Clinical Examination and Imaging Can Tell Us?

OBJECTIVE: Lesions affecting the sciatic nerve (SN) can mimic lumbar radiculopathy. In patients presenting with sciatica, approximately 10% have a nondiscogenic etiology. Through neurological examination and imaging, it may be possible to confirm nondiscogenic sciatica (NDS). This study aims to present a series of 6 patients with infragluteal NDS, highlighting clinical and imaging aspects that may suggest this diagnosis. METHODS: This is a retrospective study of 6 patients treated for NDS from 2010 to 2018. The mean and median ages were 41.2 and 38.5 years, respectively, with all patients female. RESULTS: All patients presented with sciatic pain, tenderness to deep infragluteal palpation, and a positive Tinel's sign related to the SN. Four patients were referred for surgical treatment, whereas 1 underwent pharmacological therapy and 1 underwent incisional biopsy and radiotherapy. In our series, 6 different causes for NDS were diagnosed: 1 nontumorous cause: extrauterine endometriosis and 5 tumors: metastasis from rectal adenocarcinoma, low-grade sarcoma, schwannoma, high-grade sarcoma, and myxoma. CONCLUSIONS: Differentiating between discogenic and NDS can be challenging for clinicians. When patients present with sciatic pain, a Tinel's sign related to the SN elicited at the deep infragluteal region, tenderness to deep infragluteal palpation, occasionally with an SN motor deficit and imaging findings of the lumbar spine that do not justify a discogenic source, the cause should be considered nondiscogenic and they should be scheduled for magnetic resonance imaging of the gluteal and pelvic region.

Concurrent Schwannoma and Intraneural Ganglion Cyst Involving Branches of the Common Peroneal Nerve.

Benign peripheral nerve sheath tumors are well known to neurosurgeons and a relatively commonly seen pathology. Intraneural ganglion cysts, once thought to be rare and poorly understood, are increasingly recognized in clinical practice and better understood based on the advent of high-resolution imaging. There are few reports of different nerve lesions in the same anatomic location appearing concurrently. Herein we present a patient with 2 distinct pathologies explaining 2 distinct symptom complexes-sensory changes in the superficial peroneal distribution (from a schwannoma of the superficial peroneal nerve) and mild motor weakness in the tibialis anterior (from an intraneural ganglion cyst arising from the superior tibiofibular joint affecting this motor branch). Recognition of the 2 pathologies allowed targeted surgical approaches, which led to resolution of the symptoms.

Cervical Vagal Schwannoma Causing Asymptomatic Internal Carotid Artery Compression.

BACKGROUND: Schwannoma originating from the cervical vagus nerve is a rare neoplasm. Vagal nerve schwannoma (VNS) usually occurs between the third and fifth decades of life. METHODS: We operated one patient for cervical schwannoma causing internal carotid artery (ICA) compression. RESULTS: The patient underwent en bloc excision via transcervical approach under general anesthesia. Pathological examination demonstrated the diagnosis of schwannoma. CONCLUSIONS: Our case shows that VNS can cause ICA compression and therefore brain ischemia.

Myxopapillary ependymoma of cauda equina presented with communicating hydrocephalus and papilloedema: A case report.

We reported a case of cauda equina myxopapillary ependymoma in a patient who presented with atypical history of progressive blurring of vision. Ophthalmology examination revealed relative afferent pupillary defect, binasal hemianopia and papilloedema. This case report serves as a reminder that the intraspinal tumour could be a cause of papilloedema, despite rare, should be considered in a hydrocephalus patient who presented with no intracranial pathology and minimal spinal symptoms.

Clinical outcome and ultrasonographic evaluation of treatment using polyglycolic acid-collagen tube for chronic neuropathic pain after peripheral nerve injury.

BACKGROUND: A novel polyglycolic acid (PGA)-collagen tube has been available in Japan since March 2013, and the development of high-resolution ultrasonography has recently allowed detailed evaluation of nerves. The purpose of this study was to report the clinical outcomes and evaluations of in-vivo changes under high-resolution ultrasonography for treatment using PGA-collagen tube for painful chronic nerve injury. METHODS: Four patients underwent surgical management of peripheral nerve neuroma, with nerve defects after neuroma resection reconstructed using PGA-collagen tube. Mean duration of follow-up was 30 months. Patients were surveyed to determine visual analog scale scores for pain before surgery and at final follow-up. At final follow-up, sensory function was evaluated using the Semmes-Weinstein test, static 2-point discrimination (2PD), and moving 2PD. Furthermore, we performed ultrasonography for all patients every 1 month after surgery. RESULTS: In all cases, resting pain, radicular pain, and dysesthesia were improved immediately after the operation and remained improved until the last follow-up. At the time of final follow-up, the Semmes-Weinstein test was red in 2 cases and blue in 2 cases. Mean static 2PD was 15.5 ± 5.3 mm and mean moving 2PD was 11.5 ± 5.3 mm. Ultrasonography revealed that the PGA outer wall had disappeared by 3 months postoperatively, and a hypoechoic linear shadow bridged the proximal and distal stumps. Swelling of the junction between nerve and nerve conduits was revealed at 4 months after surgery and remained until last follow-up. CONCLUSIONS: All patients were very satisfied with pain relief, but recovery of sensory function was insufficient. Ultrasonographic evaluation after using PGA-collagen tube for painful chronic peripheral nerve injury was useful for observing in-vivo changes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.