11/2007. Surgical management of lesions affecting the anterior optic pathways. Although benign neoplasms are the most common lesions of the anterior visual pathways that lend themselves to a combined neurosurgical and ophthalmic surgical treatment, malignant neoplasms, infections (especially fungal), and vascular lesions are also sometimes treated via a combined approach. Recent advances in the field of skull base surgery have made it possible to treat complicated lesions in precarious locations with increasing margins of safety and decreasing morbidity. The role of the neurosurgeon in managing selected patients with lesions of the anterior a visual pathway should not be underestimated. ( info) |
12/2007. Schwannoma with features mimicking neuroblastoma: report of two cases with immunohistochemical and ultrastructural findings. OBJECTIVE: A study of two cases of a rare variant of benign schwannoma showing areas mimicking neuroblastoma/peripheral primitive neuroectodermal tumour (PNET). methods: Sections of formalin fixed, paraffin embedded specimens were studied by tinctorial stains and immunohistochemistry, and the tissue retrieved from formalin was examined by electronmicroscopy in one case. RESULTS: The tumours were small and subcutaneous. Both showed features of benign schwannoma; one had a multinodular plexiform pattern. In addition, rosette-like structures consisting of collagenous cores surrounded by small round cells or slightly larger epithelioid cells were present. Tumour cells were positive for S100 protein, Leu7, and in one case GFAP, but were negative for neurofilament protein, synaptophysin, and MIC2. Type IV collagen surrounded individual cells. Electronmicroscopy in case 2 confirmed schwannian features (lamina, processes) and failed to show features of neuroblastoma (neuroendocrine granules). CONCLUSIONS: Benign schwannomas may contain rosette-like structures mimicking neuroblastoma/PNET. The techniques used confirmed schwannian differentiation only and eliminated neuroblastoma/PNET. These uncommon variants should be recognised by practising histopathologists to avoid erroneous diagnoses and inappropriate treatment. ( info) |
13/2007. Granular cell myoblastoma (schwannoma) of the carina in a patient with sarcoidosis. The sixth case report of granular cell myoblastoma (schwannoma) of the carina, occurring in a 22-year-old black woman, is presented. Incidental coexistent carcoidosis was present. The various theories of the histogenesis of the lesion are reviewed briefly. ( info) |
14/2007. A skull base extradural hypoglossal neurilemmoma resected via an extended posterolateral approach. The case of a 43-year-old man with a right skull base hypoglossal neurilemmoma excised via the extended posterolateral approach is presented. There is only one previous case of hypoglossal neurilemmoma in the literature. The surgical technique described is a new approach to the posterior skull base involving a suboccipital craniectomy, mastoidectomy and the removal of the lateral process of the atlas. It provides an inferior approach to the jugular foramen and hypoglossal canal that allows the lower cranial nerves to be identified as they exit from their skull base foramina. In the discussion we compare this technique to other surgical approaches previously described for access to the region of the jugular foramen. ( info) |
| BACKGROUND: cauda equina syndrome occurring as a result of spontaneous spinal subarachnoid hemorrhage (SAH) from a spinal tumor is reported to be rare. CASE DESCRIPTION: A 28-year-old woman presented at our clinic with a history of severe back pain for 10 days, progressive paraparesis, and urinary retention. Her physical examination revealed a mass located intradurally at the level of L1-2 and a massive SAH. An L1-L2, laminectomy and a hemilaminectomy from D9 to D12 were performed and the SAH was evacuated and the cord was decompressed. CONCLUSION: At the first year follow-up, her restricted dorsal and plantar flexion continued. Post-gadolinium magnetic resonance imaging revealed no mass. ( info) |
16/2007. Benign schwannoma of the digestive tract: a clinicopathologic and immunohistochemical study of five cases, including a case of esophageal tumor. We report five cases of schwannomas of the digestive tract. The patients were two men and three women, whose ages ranged from 56 to 74 years. Three cases arose in the stomach, one in the ascending colon, and one in the esophagus; the latter was a hitherto unreported location for this tumor. The schwannomas ranged from 2 to 11 cm in diameter. They were well circumscribed but not encapsulated, with interlacing bundles of spindle cells, nuclear atypia and no mitosis, interspersed with collagenous strands. Inflammatory cells were scattered throughout the tumors and a peripheral cuff of lymphoid aggregates was observed in all cases. Intracellular periodic acid-Schiff (PAS)-positive crystalloids were found in three cases; no skeinoid fibers were seen. A diffuse and intense positivity for vimentin and S-100 protein was detected in all five cases together with a variable and sometimes focal positivity for glial fibrillary acidic protein and neuron-specific enolase. None of the tumors showed expression of CD34 or the smooth muscle antigens tested. The four cases with a sufficient follow-up had a favorable outcome without any recurrence or metastasis. The morphologic and immunohistochemical features of digestive schwannomas were compared with those of other gastrointestinal stromal tumors. Schwannomas have many differences. Digestive schwannomas can be readily recognized on histologic and immunohistochemical examination. They are spindle cell tumors without epithelioid features, with a peripheral cuff of lymphoid tissue. Specific intracellular needle-shaped PAS-positive crystalloids are found in some cases, whereas skeinoid fibers are not. These tumors always express S-100 protein in a diffuse and strong manner, and they express glial fibrillary acidic protein but not express CD34. Digestive schwannomas usually are gastric tumors and have never been reported in the small bowel. They pursue a benign course and are far rarer than gastrointestinal autonomic nerve tumors. ( info) |
17/2007. Primary lymphoma of Meckel's cave mimicking trigeminal schwannoma: case report. OBJECTIVE AND IMPORTANCE: We report the first case of primary lymphoma of Meckel's cave. The ability of a lymphoma to mimic a trigeminal schwannoma, both clinically and radiographically, resulted in misdiagnosis and flawed surgical strategy. We discuss the characteristics of a Meckel's cave lymphoma on magnetic resonance images, the predisposing medical conditions that should cause the neurosurgeon to add lymphoma to the normal differential diagnosis, and appropriate management strategies. CLINICAL PRESENTATION: A 40-year-old African-American woman presented with a 5-month history of progressive facial numbness and pain in all three divisions of the left trigeminal nerve. magnetic resonance imaging revealed a mass in the left side of Meckel's cave, with extension into the lateral compartment of the cavernous sinus, without encasement of the internal carotid artery, through the foramen rotundum into the posterior aspect of the maxillary sinus, and through the foramen ovale into the pterygopalatine fossa. The diagnosis, based on clinical history and radiographic imaging, was schwannoma of Meckel's cave. The patient had a history of systemic lupus erythematosus that had been treated with intermittent steroid therapy. INTERVENTION: The surgical approach selected was a frontotemporal craniotomy with orbitozygomatic osteotomy and anterior petrosectomy. The lesion was totally excised, although the gross intraoperative appearance of the lesion was inconsistent with the preoperative diagnosis, and the pathological examination was unable to establish a histological diagnosis on the basis of frozen sections. Histological diagnosis was confirmed on permanent section after surgery as B-cell lymphoma. Evaluation for other primary sites produced negative results. The patient was then treated with cyclophosphamide (Cytotoxan; Bristol-Myers Oncology, Princeton, NJ), doxorubicin (Adriamycin; Pharmacia & Upjohn, Kalamazoo, MI), vincristine, and prednisone chemotherapy every 3 weeks for six cycles and then by radiation therapy to the affected area. CONCLUSION: The diagnosis of lymphoma should be considered for lesions affecting Meckel's cave in high-risk immunocompromised patients. The presence of an apparent dural tail in an otherwise typical schwannoma is the distinguishing characteristic of a lymphoma. The absence of hyperostosis helps differentiate it from a meningioma. At this point, the preferred surgical strategy is biopsy for diagnosis and then radiotherapy and chemotherapy rather than major cranial base surgery for total resection. ( info) |
18/2007. High-resolution ultrasonography in detection and follow-up of a tumour of the forearm. Case report. A 39-year-old man had a mass in his right flexor medial mid-forearm of unknown aetiology for two years. Preoperative high-resolution ultrasonography showed a well-defined solid mass with reduced echogenicity. The mass was excised and histopathological examination showed neurilemmoma. There had been no recurrence of the tumour six months after operation. ( info) |
19/2007. Solitary cellular schwannoma (neurilemmoma) showing malignant changes: evaluation through magnetic resonance imaging (M.R.I.), surgical intervention, and histopathology. Schwannoma (neurilemmoma) are common benign tumors arising from the peripheral nerve sheath. Malignant transformation is uncommon. A unique case showing such a transformation is reported highlighting the roles of magnetic resonance imaging, surgical intervention, and histopathology. The case was thoroughly investigated by learning the details of the sequence of events leading to the current status. The evaluation was made through magnetic resonance imaging. In addition, computed tomography and conventional radiography were used to locate any foci of calcification. Subsequently, the tumor's gross and microscopic morphology was defined by surgical intervention and histopathology. Malignant schwannoma of the left leg occupying the entire calf is extremely uncommon. Only ten cases have been reported thus far, including the current one from the Indian subcontinent. Malignant transformation in a schwannoma differs significantly from malignant nerve sheath tumors (erroneously called malignant schwannomas). An endeavour has been made to differentiate malignant transformation in schwannoma from other malignant peripheral nerve sheath tumors. An innovation in this direction is magnetic resonance imaging. This investigate procedure is imperative in such situations, along with surgery and histopathology, which may also help in classifying the condition. ( info) |
20/2007. Surgical findings in idiopathic trigeminal neuropathy mimicking a trigeminal neurinoma. Idiopathic trigeminal neuropathy is a benign disorder where the main clinical feature is facial numbness limited to the territory of one or more divisions of the trigeminal nerve, persisting for a few weeks to several years and in which no underlying disease can be identified. The case of a 37-year-old man with a brief history of sensory and motor trigeminal symptoms who showed magnetic resonance imaging (MRI) findings consistent with a small trigeminal neurinoma is reported. The patient was operated on but no tumour could be found during surgery and a biopsy was taken from the portio major. Pathological diagnosis was chronic non granulomatous inflammatory reaction with areas of coagulation necrosis. Control MRI showed complete resolution of the trigeminal abnormalities. It is concluded that in patients with MRI findings suggestive of a small trigeminal schwannoma, benign idiopathic trigeminal neuropathy should also be considered in the differential diagnosis. A conservative approach with sequential MRI studies may avoid an unnecessary surgical exploration. ( info) |