1/17. Microvascular reconstruction of the skull base: indications and procedures.PURPOSE: The aim of the current study was to review the use of free tissue transfer for reconstruction of the skull base and for coverage of intracranial contents. patients AND methods: From 1990 until 1996, revascularized flaps were transferred to the skull and the skull base in 11 patients in whom intracranial/extracranial resection of tumors of the skull base was performed in cooperation with the Department of neurosurgery. The defects resulted from removal of squamous cell carcinomas (n = 4), basal cell carcinomas (n = 4), malignant melanoma, malignant schwannoma, and malignant meningioma. Defect repair was accomplished by revascularized transfer of latissimus dorsi muscle flaps in seven cases and rectus abdominis flaps and forearm flaps in two cases each. In five patients with extensive intracranial tumor spread, reconstruction was performed for palliative reasons. RESULTS: A safe soft tissue closure of the intracranial and intradural space was achieved in all patients, whereas the contour of the facial skull and the neurocranium was satisfactorily restored at the same time. By using the entire length of the grafted muscle, the vascular pedicle could be positioned next to the external carotid artery and conveniently connected to the cervical vessels. The mean survival time of the patients with palliative treatment was 8.4 months, with an average duration of hospital stay of 24.5 days. CONCLUSIONS: Despite the increased surgical effort of revascularized tissue transfer, microvascular reconstruction of large skull base defects appears to be justified, even as a palliative measure.- - - - - - - - - - ranking = 1keywords = schwannoma (Clic here for more details about this article) |
2/17. Stereotactic radiosurgery for jugular foramen schwannomas.BACKGROUND: Jugular foramen schwannomas pose difficult management problems because of the surgical risk of lower cranial neuropathy. The indications and results of stereotactic radiosurgery are not well documented. methods: We reviewed our 10-year experience in the management of 17 patients who had jugular foramen schwannomas managed with the gamma knife. Thirteen patients previously had undergone surgery (range, 1-6 resections). Four patients had multiple cranial nerve deficits before microsurgical resection; 12 developed multiple lower cranial nerve palsies after resection. Four patients underwent radiosurgery based on imaging criteria alone. Conformal dose planning (tumor margin dose of 12-18 Gy) successfully encompassed the irregular tumor volumes in all patients. RESULTS: Follow-up varied from 6 to 74 months. Tumor size decreased in eight patients, remained stable in eight, and increased in one patient during the average follow-up interval of 3.5 years. Six patients improved and 10 others retained their preradiosurgery clinical status. One patient had an increase in tumor size and clinical deterioration 6 months after radiosurgery and underwent microsurgical resection. No patient developed new cranial nerve or other neurological deficits after radiosurgery. CONCLUSIONS: We believe that gamma knife radiosurgery is an effective alternative to microsurgical resection for patients who have small tumors and intact lower cranial nerve function. It is also effective for patients who have residual or recurrent tumors after microsurgical resection.- - - - - - - - - - ranking = 6keywords = schwannoma (Clic here for more details about this article) |
3/17. Schwannomatosis in a child--or early neurofibromatosis type 2.A case of multiple cervical schwannomas in a five-year-old boy, without other evidence of neurofibromatosis type 2, is described. Schwannomatosis is a disorder characterized by the presence of multiple schwannomas in the absence of neurofibromatosis type 2 that has only been recognized in the last 15 years. The clinical and genetic features of neurofibromatosis types 1 and 2 and schwannomatosis are compared and contrasted. This patient with possible schwannomatosis is presented to illustrate the potential pitfalls of making this diagnosis in the paediatric age group and to increase awareness of the debate on whether this is a distinct entity or a form fruste of neurofibromatosis type 2.- - - - - - - - - - ranking = 4keywords = schwannoma (Clic here for more details about this article) |
4/17. Ancient schwannoma of the infratemporal fossa.This article describes a case of ancient schwannoma of the infratemporal fossa. Ancient schwannoma is a rare variant of the neurilemmoma, which clinical findings and radiographic features suggest is a slow-growing, benign tumour. Histopathologic features such as hypercellularity with nuclear atypia can make accurate diagnosis of this tumour difficult. The treatment of this tumour is complete resection, and the prognosis is good.- - - - - - - - - - ranking = 6keywords = schwannoma (Clic here for more details about this article) |
5/17. Imaging of an exceptional tumor: myxoid chondrosarcoma of the jugular foramen.We report on an unusual tumor of the jugular foramen in a 26-year-old male. The lesion showed moderate enhancement on CT scan and a higher signal intensity on T2-weighted MR images than on T1, with a massive enhancement after gadolinium. Tumor was entirely removed surgically and histology was consistent with a low-grade myxoid chondrosarcoma, an exceptional tumor in this location. The differential diagnosis includes paragangliomas, schwannomas, metastases and meningiomas. Radiological and histological features can also mimic chordomas. However, immunohistochemical analysis certifies the diagnosis.- - - - - - - - - - ranking = 1keywords = schwannoma (Clic here for more details about this article) |
6/17. Solitary fibrous tumor of the hypoglossal nerve.Summary: We report a case of solitary fibrous tumor (SFT) causing isolated hypoglossal nerve palsy. The neuroimaging appearance of the tumor was indistinguishable from that of schwannoma or meningioma. Immunohistochemical tests demonstrated strong reactivity for CD34 but an absence of staining for S100 and epithelial membrane antigen; this profile is indicative of an SFT. SFTs are mesenchymal tumors that can affect the dura-covered segments of cranial nerves. They may be considered in the differential diagnosis of an isolated cranial nerve palsy.- - - - - - - - - - ranking = 1keywords = schwannoma (Clic here for more details about this article) |
7/17. Reversible cochleo-vestibular deficits in two cases of jugular foramen tumor after surgery.Primary jugular foramen (JF) tumor, such as glomus jugular tumor or JF schwannoma, may manifest as a lower cranial nerve deficit; in addition, it can be accompanied by deafness or vertigo if it affects the cranial nerve (CN) VIII. Recently, we encountered JF schwannoma 1 and glomus jugulare tumor 1. Both cases invaded the adjacent cerebellopontine angle, leading to cochleo-vestibular deficits prior to the operation. After surgery, recovery of the audiovestibular function, including hearing, auditory brainstem response and caloric response, was anticipated in both patients. Therefore, cochleo-vestibular deficits in JF tumors can be attributed to compression neuropathy, rather than tumor infiltration.- - - - - - - - - - ranking = 2keywords = schwannoma (Clic here for more details about this article) |
8/17. Utility of image guided surgery in the diagnosis of pterygopalatine fossa lesions.OBJECTIVES: To describe the utility of image guided surgery in the diagnosis of pterygopalatine fossa lesions and to discuss the varied pathologic diagnoses from this area. STUDY DESIGN: Case series presentation. methods: Three cases of pterygopalatine fossa lesions were accessed and biopsied by way of a middle meatus antrostomy approach into the pterygopalatine fossa under image guidance for rapid localization. RESULTS: The diagnoses of melanoma, squamous cell carcinoma, and schwannoma were obtained with minimal morbidity with image guidance. More extensive external approaches were avoided, and appropriate treatment was started without delay. The utility of the image guided approach will be discussed along with the varied pathologies encountered in the pterygopalatine fossa. CONCLUSIONS: 1). One must recognize the diverse, yet related, symptoms of patients presenting with pterygopalatine fossa lesions. Early recognition as well as skull-base imaging is crucial. 2). biopsy, in addition to imaging, is necessary for diagnosis and may be achieved with little morbidity and increased accuracy using the image guided surgery middle meatus antrostomy approach to the pterygopalatine fossa. 3). The origin of lesions that involve the pterygopalatine fossa may be difficult to identify. Involvement of the pterygopalatine fossa by malignancy may be by contiguous spread, by way of metastasis, or by perineural invasion.- - - - - - - - - - ranking = 1keywords = schwannoma (Clic here for more details about this article) |
9/17. Jugular foramen tumors: diagnosis and treatment.OBJECT: Jugular foramen tumors are rare skull base lesions that present diagnostic and complex management problems. The purpose of this study was to evaluate a series of patients with jugular foramen tumors who were surgically treated in the past 16 years, and to analyze the surgical technique, complications, and outcomes. methods: The authors retrospectively studied 102 patients with jugular foramen tumors treated between January 1987 and May 2004. All patients underwent surgery with a multidisciplinary method combining neurosurgical and ear, nose, and throat techniques. Preoperative embolization was performed for paragangliomas and other highly vascularized lesions. To avoid postoperative cerebrospinal fluid (CSF) leakage and to improve cosmetic results, the surgical defect was reconstructed with specially developed vascularized flaps (temporalis fascia, cervical fascia, sternocleidomastoid muscle, and temporalis muscle). A saphenous graft bypass was used in two patients with tumor infiltrating the internal carotid artery (ICA). facial nerve reconstruction was performed with grafts of the great auricular nerve or with 12th/seventh cranial nerve anastomosis. Residual malignant and invasive tumors were irradiated after partial removal. The most common tumor was paraganglioma (58 cases), followed by schwannomas (17 cases) and meningiomas (10 cases). Complete excision was possible in 45 patients (77.5%) with paragangliomas and in all patients with schwannomas. The most frequent and also the most dangerous surgical complication was lower cranial nerve deficit. This deficit occurred in 10 patients (10%), but it was transient in four cases. Postoperative facial and cochlear nerve paralysis occurred in eight patients (8%); spontaneous recovery occurred in three of them. In the remaining five patients the facial nerve was reconstructed using great auricular nerve grafts (three cases), sural nerve graft (one case), and hypoglossal/facial nerve anastomosis (one case). Four patients (4%) experienced postoperative CSF leakage, and four (4.2%) died after surgery. Two of them died of aspiration pneumonia complicated with septicemia. Of the remaining two, one died of pulmonary embolism and the other of cerebral hypoxia caused by a large cervical hematoma that led to tracheal deviation. CONCLUSIONS: Paragangliomas are the most common tumors of the jugular foramen region. Surgical management of jugular foramen tumors is complex and difficult. Radical removal of benign jugular foramen tumors is the treatment of choice, may be curative, and is achieved with low mortality and morbidity rates. Larger lesions can be radically excised in one surgical procedure by using a multidisciplinary approach. Reconstruction of the skull base with vascularized myofascial flaps reduces postoperative CSF leaks. Postoperative lower cranial nerves deficits are the most dangerous complication.- - - - - - - - - - ranking = 2keywords = schwannoma (Clic here for more details about this article) |
10/17. Jugular foramen schwannoma: surgical experience in six cases.PURPOSE: Schwannomas of the lower cranial nerves are rare tumours. We have surgical experience in six patients. MATERIAL AND methods: We have retrospectively reviewed the files of the six patients with jugular foramen schwannomas that were treated in multidisciplinary collaboration in the departments of neurosurgery and ENT. RESULTS: From a clinical point of view, the most important finding was that these tumours usually mimic a vestibular schwannoma. The imaging findings however always allowed the differentiation. The surgical technique included in all cases a suboccipital approach for the intracranial part. When large, the extracranial extension had to be removed through a lateral cervical or transfacial approach. There was no mortality and minor morbidity, with good functional outcome. In subtotally removed tumours, recurrence occurred. CONCLUSION: A combined neurosurgical and ENT approach allows for safe removal of these often large skull base tumours.- - - - - - - - - - ranking = 6keywords = schwannoma (Clic here for more details about this article) |
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