Malignant peripheral nerve sheath tumor mimicking carotid body tumor--case report and review

Malignant peripheral nerve sheath tumor is a rare neurogenic tumor that usually presents in geriatic patients. Typically, it is found in the trunk and extremities and rarely presents in the head and neck region. It may mimic a carotid body tumor when it presents in the neck. We report the first case of malignant peripheral nerve sheath tumor of the vagus nerve in an adolescent boy. He presented with an asymptomatic lateral neck lump that was thought to be a benign schwannoma on preoperative imaging. We describe the diagnostic dilemma and management difficulties in this patient and review the literature.     

Benign neural sheath tumours of major nerves: Characteristics in 119 surgical cases

Summary Peripheral benign nerve sheath tumours are infrequent tumours and affect major nerve trunks. Some authors have indicated a high and prohibitive incidence of neurological injury in resection of these lesions. The authors describe their findings in a retrospective study comprising 119 patients with spontaneous benign nerve sheath tumours of the peripheral nervous system. Seventy-three patients had a schwannoma, 41 had neurofibroma and 5 had plexiform neurofibroma; 25 of the 119 patients suffered from neurofibromatosis. All schwannomas were excised completely and the outcome of patients was 41.0% improved, 6.8% worsened, 52.0% unchanged. Twenty-eight neurofibromas were excised completely and 13 subtotally; the outcome for patients was 19.5% improved, 19.5% worsened and 61% unchanged. All plexiform neurofibromas were removed subtotally and the outcome for patients was 20% improved and 80% unchanged. The best surgical results at average follow-up of 6 years were observed in the patients with schwannoma, the worst in those with plexiform neurofibroma. Our results demonstrated that it is often possible to remove schwannomas as well as neurofibromas with an acceptable risk of injury to the nerve.     

Schwannoma of the posterior tibial nerve: the problem of delay in diagnosis

Schwannomas are the most common tumours of the sheath of peripheral nerves. The clinical diagnosis is usually straightforward, but may be delayed for many years in a schwannoma of the posterior tibial nerve. The symptoms are often attributed to entrapment neuropathy or to lumbosacral radiculopathy. We describe 25 patients with a schwannoma of the posterior tibial nerve. Only three were diagnosed within a year of presentation. The mean time to diagnosis was 86.5 months with a median of 48 months (2 to 360). All the patients complained of pain, which was felt specifically in the sole of the foot in 18. A Tinel sign was detected in all 25 patients. MRI confirmed the diagnosis in all the cases in which it had been undertaken. Surgical resection of the lesion abolished the neuropathic pain. In patients with a long history of neuropathic pain in the lower limb in whom lumbar and pelvic lesions have been excluded, a benign tumour of the sheath of a peripheral nerve may explain the symptoms. Surgical resection of the tumour is safe and effective.     

周围神经鞘瘤的显微外科治疗

目的：探讨周围神经鞘瘤显微手术治疗的效果。方法回顾性分析54例经显微手术切除神经鞘瘤的疗效。结果本组54例均取得良好效果。经过1～2年的随访,5例恶性神经鞘瘤无复发;良性神经鞘瘤,1例术后出现皮肤感觉麻木,3例出现运动功能障碍,6个月后基本恢复。结论周围神经鞘瘤经显微手术治疗可最大限度地降低神经的损伤,可最大程度地完整切除肿瘤,对于恶性神经鞘瘤,扩大切除可降低复发。     

Bifocal schwannoma of the sciatic nerve: a case report

Schwannoma is a benign tumor generally observed on peripheral nerves. A sciatic localization is rare, observed in 1% of the patients. Multiple localizations have been reported in exceptional cases. We report the case of a bifocal schwannoma observed at the bifurcation of the sciatic nerve in a high-level athlete. The misleading clinical presentation of this localization causes a delay in diagnosis.     

A large pelvic mass in a 39-year-old man

Schwannomas are encapsulated, usually benign, tumors composed of well-differentiated Schwann cells, arising from the neural sheath of peripheral nerves. The most common type of benign schwannoma is the acoustic neuroma arising from the eighth cranial nerve. Retroperitoneal schwannomas account for 0.5-3% of the retroperitoneal tumors in most series. We present a case of a 39-year-old man with a pelvic mass, arising from a sacral nerve root, diagnosed as a schwannoma.     

A rare cause of chronic sciatic pain: Schwannoma of the sciatic nerve

Schwannomas are common, benign tumors of the shelth of peripheral nerves. Sciatic schwannomas are rare. Their symptomatology usually mimics sciatic pain due to a herniated disc, which can delay the diagnosis. If there is no lumbar pain and lumbar MRI is normal, the sciatic nerve must be clinically and radiologically examined all along its course. We report a case of sciatic nerve schwannoma presenting with chronic sciatica which was diagnosed and monitored radiologically for several years before successful surgical resection.     

Nasal schwannoma

A 36-year-old man with a nasal septal mass is presented. The diagnosis of a benign neoplasm arising from peripheral nerve Schwann cells was made by excisional biopsy. A benign nerve sheath tumor may be either a schwannoma or neurofibroma. Schwannomas may be distinguished from neurofibroma by clinical and histologic criteria. Malignant degeneration and intracranial extension may complicate the course of a nasal schwannoma. Complete excision is the preferred therapy.     

Hybrid neurofibroma/schwannoma is overrepresented among schwannomatosis and neurofibromatosis patients

We analyzed the histologic features of peripheral nerve sheath tumors occurring in 14 patients with schwannomatosis. Among a total of 31 tumors, 19 tumors (61%) showed schwannoma-like nodules within a neurofibroma-like tumor, corresponding to hybrid neurofibroma/schwannoma. At least 1 hybrid tumor occurred in 10 of 14 (71%) schwannomatosis patients. We then retrieved cases of hybrid tumors without documented relation to schwannomatosis from our database and identified 41 tumors arising in 23 patients. More than half of these patients (14/23) were reported to suffer from multiple peripheral nerve sheath tumors, favoring a tumor syndrome. Indeed, analysis of clinical records revealed the diagnosis of neurofibromatosis type 2 (NF2) in 26% (6/23), neurofibromatosis type 1 (NF1) in 9% (2/23), definite schwannomatosis in 4% (1/23), and possible schwannomatosis in 13% (3/23) of patients with multiple nerve sheath tumors. Our findings suggest that hybrid neurofibroma/schwannoma represents a common tumor type in schwannomatosis and shows a striking association with neurofibromatoses.     

Plexiform schwannoma of the esophagus in a child with neurofibromatosis type 2

Schwannoma is a benign neoplasia of the peripheral nerve sheath. Its localization in the gastrointestinal tract, and in particular in the esophagus, is very rare. According to the existing literature esophageal schwannoma has been reported so far only in adult patients. We report the case of an 11 year old patient with neurofibromatosis, type 2, who underwent surgical excision of a plexiform schwannoma of the esophagus.     

Peripheral nerve sheath tumors of the paranasal sinuses

Only 4% of peripheral nerve sheath tumors of the head and neck occur in the paranasal sinuses. The most commonly involved sinus is the maxillary antrum and the most common histologic type is benign schwannoma. Two new cases of schwannoma occurring in the sphenoid and maxillary sinuses are reported. The clinical pathologic, and radiographic features of these lesions are reviewed.     

Schwannoma and neurofibroma of the posterior tibial nerve presenting as tarsal tunnel syndrome: review of the literature with two case reports

We present two case reports of peripheral nerve tumors (schwannoma and neurofibroma) that presented as tarsal tunnel syndrome for many years. There has never been a report of multiple neurofibroma of the posterior tibial nerve presenting as a tarsal tunnel syndrome. Both patients were treated surgically with good outcomes.     

Unexpected ulnar nerve schwannoma. The reasonable risk of misdiagnosis

Peripheral nerve tumors are rare clinical entities that can present with mild symptoms and no neurological deficit. The authors describe one case of asymptomatic schwannoma of the ulnar nerve in a 64-year-old man. The mass was associated with mild and sporadic discomfort due to the mass size; the clinical neurological examination was not conclusive, with Tinel's sign negative; surgery confirmed the nervous origin of the tumor and the histopathologic exam confirmed the diagnosis of schwannoma. These tumors are difficult to diagnose clinically and have often been confused with other benign tumors such as lipomas, hemangiomas, synovial cysts, neurofibromas, etc. Clinical care is important to prevent, during the surgery, the unfortunate resection of the nerve; all too frequently this diagnosis is made intraoperatively or postoperatively with the potential to compromise the outcome of the treatment. An appropriate degree of awareness is necessary for the inclusion of peripheral nerve tumors as a differential diagnosis of an upper extremity mass.     

Facial Nerve Function After Parotidectomy for Neoplasms with Deep Localization

PURPOSE: To determine whether the deep location of a parotid gland neoplasm is specific risk factor for facial nerve paralysis after parotidectomy. METHODS: We retrospectively reviewed 88 patients, including 59 with a benign superficial neoplasm of the parotid treated by superficial parotidectomy (group 1); 5 with a benign deep neoplasm treated by total parotidectomy (group 2); 20 with a malignant superficial neoplasm treated by total parotidectomy (group 3); and 4 with a malignant deep neoplasm treated by total parotidectomy (group 4). RESULTS: Temporary facial nerve paralysis developed in 10.3%, 20%, 10%, and 50% of groups, 1, 2, 3, and 4, respectively. Permanent facial nerve paralysis developed in 0%, 0%, 10% and 50% of groups 1, 2, 3, and 4, respectively. CONCLUSION: The risk factor associated with nerve damage resulting from surgery for parotid neoplasms were malignancy and deep localization. However, the deep location of a benign tumor was not a major risk factor for permanent paralysis.     

Malignant schwannoma in the posterior tibial nerve

Our group have studied a patient affected by a malignant schwannoma in the posterior tibial nerve. Schwannomas are uncommon neoplasms that originate from the Schwann cells of the peripheral nerves: the most common forms are benign. Malignant transformation is rarer. The therapy is surgical and the operation undertaken, if possible, should be the amputation. Alternatively, where amputation is not possible due to the specific localisation or due to patient refusal, the alternative must be the largest and most radical excision possible.     

耳屏周小切口在腮腺良性肿瘤切除中的应用

【摘要】目的评估耳屏周小切口在腮腺良性肿瘤切除术中应用的临床价值。方法30例腮腺良性肿瘤患者,应用耳屏周小切口行浅叶部分切除、保留面神经和耳大神经的腮腺良性肿瘤切除术。术后随访3～24个月,观察耳屏周小切口的美观度及临床疗效。结果所有患者均临床Ⅰ期愈合,术后腮腺功能良好,无涎瘘发生。随访,患者双侧外形对称,无凹陷等畸形,手术切口隐蔽,患者对耳周切口美学效果满意。本研究中出现术后暂时性面瘫患者2例,皮质激素并配合神经营养药物综合治疗后3个月均恢复正常;出现术后耳垂麻木不适患者4例,手术后3～10个月均逐渐恢复。本研究中所有患者均未出现味觉出汗综合征,无肿瘤复发。结论耳屏周小切口隐蔽、瘢痕小、并发症低,术后美容效果理想。     

Would a Massive Intra-abdominal Malignant Peripheral Nerve Sheath Tumor with Growth into the Inguinal Canal and Scrotum Preclude Surgical Option? A Case Report and Review of Literature

Malignant peripheral nerve sheath tumors (MPNST) are rare spindle-cell sarcomas derived from Schwann cells or pluripotent cells of the neural crest accounting for less than 10 % of all soft tissue sarcomas. They arise from major or minor peripheral nerve fibers or their sheaths. The World Health Organization coined the term MPNST for tumors of neurogenic origin with similar biological behavior replacing all the previous heterogeneous and, often, confusing nomenclature including malignant schwannoma, malignant neurilemmoma, and neurofibrosarcoma. The retroperitoneum and the lower extremities are the most common sites, but MPNST may arise anywhere in the body. Its location in the retroperitoneum in a patient without neurofibromatosis is an exceedingly rare occurrence. Imaging is routinely performed to assess the extent of the disease and to plan surgical resection. Surgical resection is the first line of therapy, ideally with total removal of the tumor. Owing to a high risk of recurrence with incomplete resection, postoperative irradiation and chemotherapy are necessary; however, they are often used as adjuvant therapy even if the tumor is completely resected.     

原发性膀胱神经鞘瘤1例报告并文献复习

目的 探讨原发于膀胱的神经鞘瘤和恶性周围神经鞘瘤在组织病理学、临床表现、治疗和预后上的特点,确立两者的鉴别诊断思路.方法 回顾1例原发于膀胱的神经鞘瘤的临床诊疗过程,结合有关膀胱神经鞘瘤及膀胱恶性周围神经鞘瘤的文献资料进行分析.结果 在组织病理和免疫组化方面,原发于膀胱的神经鞘瘤和恶性周围神经鞘瘤有明显差异.结论 原发于膀胱的神经鞘瘤临床极其少见,易与膀胱常见肿瘤混淆,造成误诊,免疫组化为重要的确诊依据.膀胱恶性周围神经鞘瘤应以高度恶性的软组织肉瘤进行处理.临床上应重视两种疾病的鉴别,以正确地指导临床诊疗.     

Schwannoma of the diaphragm--a pediatric case report and review of the literature

Diaphragmatic tumors are uncommon and difficult to diagnose in the pediatric population. Schwannoma is a benign, slow-growing peripheral nerve sheath tumor that is most commonly associated with the extremities in childhood. We herein report a schwannoma of the diaphragm in a pediatric patient and review the pediatric literature.     

Diagnosis and Management of Schwannomas Originating from the Cervical Vagus Nerve

Introduction

A schwannoma is a benign, slow growing, encapsulated nerve sheath tumour. Presentation of a schwannoma is a diagnostic and management challenge.

Methods

Internet searches of PubMed/MEDLINE^® for all articles listing schwannomas of the vagus nerve in the cervical/neck region (1980–2012) were undertaken to ascertain diagnostic pitfalls. The references of all articles were cross-checked to include all pertinent contributions. Further articles were traced through reference lists.

Results

Schwannomas are solitary, well circumscribed and medial to the carotid sheath. Preoperative diagnoses of schwannomas in the lateral part of the neck can cause confusion with its nerve of origin (ie whether it arises from the vagus nerve or a sympathetic chain). Computed tomography and magnetic resonance imaging reveal valuable information regarding the location and origin of the tumour as well as aiding surgical planning. The diagnosis can be confirmed intraoperatively. Postoperative recovery of neurological function is dependent on the type of surgery. Histopathological studies searching for classical features and immunohistochemical staining for S100 also confirm the diagnosis.

Conclusions

Schwannomas should be considered in the differential diagnoses of unusual masses in the neck. Preoperative imaging elicits valuable information regarding the location and origin of schwannomas and histopathology confirms the diagnosis.