1/39. Primary melanocytic schwannoma of cervical sympathetic chain.BACKGROUND: Primary melanocytic schwannoma arising from the cervical sympathetic chain is a rare pigmented nerve sheath tumor. Two cases are presented from an academic medical center. patients and methods patients were initially seen with an enlarging neck mass associated with sympathetic nervous system dysfunction. radiography demonstrated a mass located posterior to the carotid sheath. Primary therapy consisted of surgical excision and postoperative radiation therapy. RESULTS: The tumors were found to be melanocytic schwannomas arising from the cervical sympathetic chain. The pathologic characteristics of this neoplasm are reviewed. One patient remained disease free for 12 years after treatment, whereas 1 patient died as a result of local recurrence and distant metastases. CONCLUSIONS: Melanocytic schwannoma of the cervical sympathetic chain is a rare nerve sheath tumor of the head and neck that may be misdiagnosed as malignant melanoma. The clinical behavior of this neoplasm is variable. Preoperative neurologic findings, anatomic location, electron microscopy, and immunohistochemistry findings help to establish the diagnosis, and electron microscopy may have a role in distinguishing between benign and malignant lesions. Complete surgical excision is the treatment of choice.- - - - - - - - - - ranking = 1keywords = sheath (Clic here for more details about this article) |
2/39. Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma: a case report with an immunohistochemical study.A rare example of malignant transformation in an ancient schwannoma arising in the right side of the neck of a 51-year-old man without any clinical manifestations suggesting neurofibromatosis is described. The tumor, approximately 4 cm at its largest dimension, was well circumscribed and had a direct connection with the sympathetic nerve. Microscopically, the central portion of the tumor showed features of ancient schwannoma characterized by extensive hyalinization with cystic degeneration, scattered spindle cells with hyperchromatic and tapered nuclei, and some symplastic changes. However, predominantly in the outer portion, a proliferation of spindle-shaped cells with enlarged nuclei was present. The nuclei of these cells showed irregular contours, coarse granular chromatin texture, and conspicuous nucleoli. Mitotic figures and small necrotic foci with scattered apoptotic bodies were also seen. Immunohistochemically, S-100 protein was almost negative in areas consisting of overtly atypical cells where the mitotic index evaluated with MIB-1 antibody was 30.5%. In contrast, S-100-positive bland spindle cells were scattered in an extensively hyalinized area with a labeling index less than 3%. P53 protein was strongly positive in atypical spindle cells. Although it is a very uncommon event, definite nuclear atypia, frequent mitotic figures, and the existence of small necrotic foci should be recognized as indicating a diagnosis of malignant degeneration of benign schwannoma. immunohistochemistry would be useful as an ancillary technique in such a setting.- - - - - - - - - - ranking = 1.3333333333333keywords = sheath (Clic here for more details about this article) |
3/39. Cervical schwannoma: a case report and eight years review.Schwannomas are peripheral nerve tumours of nerve sheath origin. We report one case of cervical schwannoma originating from the brachial plexus. A 56-year-old man presented with a slow-growing mass on the right side of his neck that had been noted for more than 10 years. During operation, a well-encapsulated mass was seen beneath the brachial plexus with adhesion to the plexus element. It was reported as a schwannoma. Three days after surgery, the patient had a motor deficit of the right upper arm and neurological examination showed a CV nerve deficit. The neurological function recovered completely after three months. In addition, the other five cases of cervical schwannoma seen in our hospital between March 1990 and June 1998 are also reviewed. All patients had surgery. The pre-operative symptoms, impressions, and post-operative neurological status were shown and discussed. Only two cases were diagnosed as neurogenic tumour pre-operatively. Post-operatively, one patient had transient neurological deficit and another one had permanent deficit.- - - - - - - - - - ranking = 0.33333333333333keywords = sheath (Clic here for more details about this article) |
4/39. Glandular malignant peripheral nerve sheath tumor: an unusual case showing histologically malignant glands.In this report, we describe a highly unusual case of glandular malignant peripheral nerve sheath tumor presenting as a neck mass in a previously healthy 29-year-old man. Grossly, the tumor was found to arise from a swollen peripheral nerve trunk. The tumor was largely composed of spindle cells that demonstrated marked nuclear pleomorphism and numerous abnormal mitotic figures. In addition, histologically malignant glandular structures lined by simple nonciliated columnar cells with goblet cells were found clustered in the center of the tumor. Examination of the swollen peripheral nerve trunk revealed the presence of a plexiform neurofibroma. The spindle cells were positive for S100. The glands were negative for S100 but positive for keratin, epithelial membrane antigen, and neuroendocrine markers (somatostatin, chromogranin, Leu-7, and calcitonin). This patient was subsequently diagnosed as having von Recklinghausen disease and died of tumor metastasis to the lungs 34 months after the presentation. To our knowledge, only 3 similar cases have been previously described in the literature.- - - - - - - - - - ranking = 1.6666666666667keywords = sheath (Clic here for more details about this article) |
5/39. Unusual presentation of schwannoma.Schwannomas are slow growing benign tumours arising from the nerve sheath. Two cases of schwannoma arising from the vagus nerve are presented here. One case was found in a 6-year-old boy and another one in a 30-year-old man. In the first case the tumour was detected on the left side of the neck just below the angle of the mandible, and in the second case it was found on the lower part of the right side of the neck. Histopathology confirmed the diagnosis as first one to be of Antoni-A type and the second one to be of Antoni-B type. Both the tumours were excised and on follow-up the patients were doing well.- - - - - - - - - - ranking = 0.33333333333333keywords = sheath (Clic here for more details about this article) |
6/39. Schwannoma of the parapharyngeal space.A schwannoma (or neurilemmoma) of the parapharyngeal space is a rare tumor in the head and neck region arising from the sheath of cranial nerves and/or the sympathetic chain. In the early stages of growth, there is usually a lack of symptoms because of the anatomical localization and slow growth of the tumor. The large dimension of the mass at presentation makes it difficult to perform a functional surgery, and in many cases the operation worsens the nerve status. The choice of surgical approach is of paramount importance in both preserving nerve function and achieving vascular control. The authors report a case and discuss the English literature.- - - - - - - - - - ranking = 0.33333333333333keywords = sheath (Clic here for more details about this article) |
7/39. Malignant melanoma with a myxoid stroma: a diagnostic pitfall on fine-needle aspiration biopsy.Malignant melanoma (MM), both primary and metastatic, may be associated with a prominent myxoid stromal reaction causing diagnostic confusion on fine-needle aspiration biopsy (FNAB), most often with sarcomas that demonstrate a myxoid stroma, particularly malignant peripheral nerve sheath tumor (MPNST). We present a case of a 32-yr-old man with no past medical history who presented with a unilateral neck mass clinically suspicious for lymphoma. FNAB produced a specimen composed of large sheets of anaplastic cells encased in a myxoid stroma that was S100 and vimentin-positive but HMB-45-negative. A diagnosis of MPNST was made. Excision demonstrated a metastatic MM of unknown primary, with a prominent myxoid stromal reaction. A repeat HMB-45 was again negative. Electron microscopy demonstrated intracytoplasmic melanasomes and cisternae of rough endoplasmic reticulum with intracisternal parallel tubules, confirming the diagnosis. Although HMB-45 is typically negative in both tumors, S100 should be strongly positive in myxoid MM and only focal in MPNST.- - - - - - - - - - ranking = 0.33333333333333keywords = sheath (Clic here for more details about this article) |
8/39. Cervical sympathetic schwannoma: case report.OBJECTIVE AND IMPORTANCE: Approximately 20 to 27% of neck masses in the parapharyngeal space may be benign nerve sheath tumors. Cervical sympathetic chain schwannomas or vagal nerve schwannomas are most common. We report a patient with a cervical sympathetic chain schwannoma. CLINICAL PRESENTATION: The patient was a 47-year-old Caucasian man with a 7-month history of a painless, enlarging right neck mass. No hoarseness or Horner's syndrome was found preoperatively. Formal head and neck examination in the otolaryngology department revealed no vocal cord dysfunction. INTERVENTION: By use of a standard right carotid incision, a tumor was identified growing from the cervical sympathetic chain posterior to the carotid bifurcation. A gross total resection was performed and a section of the cervical sympathetic chain was sacrificed. CONCLUSION: Cervical sympathetic chain schwannomas are unusual tumors that require microneurosurgical resection for cure. We discuss the differential diagnosis, evaluation, surgical management, and pathological characteristics of such tumors and review the literature.- - - - - - - - - - ranking = 0.33333333333333keywords = sheath (Clic here for more details about this article) |
9/39. Ectopic hamartomatous thymoma: a case report with immunohistochemical and ultrastructural studies.A case of ectopic hamartomatous thymoma (EHT) arising in the supraclavicular region of a 52-year-old male is presented. The well-defined tumor measuring 1.7x1.5x0.7 cm consisted of three components: spindle cell (70%), epithelial (25%), and adipose (5%). The spindle cell component was characterized by sheet-like, haphazard and short fascicular arrangements of bland spindle cells. Neither mitotic figures nor cellular pleomorphism were found. Admixed with, and adjacent to, the spindle cell areas was an obviously epithelial component of variable appearance, ranging from glandular spaces lined by mainly cuboidal clear cells, irregularly anastomosing cords, and strands of epithelial cells to irregular solid nests of squamous epithelium with dark and clear cytoplasm. Myoepithelial cells were also observed. Immunohistochemically, the spindle cells were strongly and diffusely positive for cytokeratins and some of them were positive for BRST2, alpha-smooth muscle actin, and CD10. The tumor was negative for S-100 protein, glial fibrillary acidic protein, and CD34. Ultrastructurally, tonofilaments and desmosomes were observed in the spindle cells. The findings indicate an epithelial origin. The patient was well without recurrence or metastasis 8 months after excision. Pathologists and clinicians should be aware of the existence of ectopic hamartomatous thymoma in the supraclavicular or suprasternal region and should differentiate it from a high-grade sarcoma, such as biphasic synovial sarcoma or glandular malignant peripheral nerve sheath tumor.- - - - - - - - - - ranking = 0.33333333333333keywords = sheath (Clic here for more details about this article) |
10/39. neck schwannomas.Schwannomas are peripheral nerve tumours of nerve sheath origin. Twenty-five to 45 percent of extracranial schwannomas occur in the head and neck region. We present 2 cases of schwannomas that arise from the vagus and cervical plexus. These lesions are uncommon and most often present as asymptomatic solitary neck mass. Preoperative diagnosis can be difficult and conservative surgical excision remains the treatment of choice, often requiring sacrifice of a portion of the nerve.- - - - - - - - - - ranking = 0.33333333333333keywords = sheath (Clic here for more details about this article) |
| | Next -> |