Mixed tumour of schwannoma and meningioma in a patient with neurofibromatosis-2 : a case report.
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The co-existence of schwannoma and meningioma as a mixed intracranial tumour is uncommon and so far only eight cases have been published in the literature. Because of rarity, we report a unique case of mixed tumour having schwann cell and meningeal components, in a patient with neurofibromatosis type -2 (NF-2). The possible mechanisms for the occurrence of these mixed tumours are discussed. (+info)
The neurofibromatosis type 2 gene product, merlin, reverses the F-actin cytoskeletal defects in primary human Schwannoma cells.
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Schwannoma tumors, which occur sporadically and in patients with neurofibromatosis, account for 8% of intracranial tumors and can only be treated by surgical removal. Most schwannomas have biallelic mutations in the NF2 tumor suppressor gene. We previously showed that schwannoma-derived Schwann cells exhibit membrane ruffling and aberrant cell spreading when plated onto laminin, indicative of fundamental F-actin cytoskeletal defects. Here we expand these observations to a large group of sporadic and NF2-related tumors and extend them to schwannomatosis-derived tumors. Mutation at NF2 correlated with F-actin abnormalities, but the extent of morphological change did not correlate with the type of NF2 mutation. We used a recently described molecular strategy, TAT-mediated protein transfer, to acutely introduce the NF2 protein, merlin, into primary human schwannoma cells in an attempt to reverse the cytoskeletal phenotype. Abnormal ruffling and cell spreading by cells with identified NF2 mutations were rapidly reversed by introduction of TAT-merlin. The effect is specific to TAT-merlin isoform 1, the growth-suppressive isoform of merlin. TAT-merlin isoform 2, a TAT-merlin mutant (L64P), and merlin lacking TAT were ineffective in reversing the cytoskeletal phenotype. Results show that merlin isoform 1 is sufficient to restore normal actin organization in NF2-deficient human tumor cells, demonstrating a key role for merlin in the NF2 phenotype. These results lay the foundation for epigenetic complementation studies in NF2 mouse models and possibly for experiments to evaluate the utility of merlin transduction into patients as protein therapy. (+info)
A case of dumbbell tumor of the superior mediastinum removed by combined thoracoscopic surgery.
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We report a case of a neurogenic dumbbell tumor in the superior mediastinum resected completely by the combined application of thoracoscopy and neurosurgery performed by an orthopedic surgeon. A 54-year-old female was admitted because her chest X-ray showed a superior mediastinal mass. Computed tomography and magnetic resonance imaging revealed that the tumor was extradural dumbbell-shaped and compressed the spinal cord through the intervertebral foramen between Th2 and Th3. First, she underwent laminectomy of the vertebrae (Th1similarTh3) and separation of the tumor from the dura mater and the root of the second left intercostal nerve in the right semilateral position. Then in the same position, three thoracic ports were placed and the tumor was resected completely using thoracoscopy in a one-stage operation. The pathological diagnosis was neurilemmoma. There has been no sign of serious neurologic deficits or of recurrence four years after the operation. Thus, the procedure is a minimally invasive approach, which is both safe and useful. (+info)
Intrasellar schwannoma mimicking pituitary adenoma: a case report.
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Intrasellar location of schwannoma is extremely rare, although intracranial schwannomas account for up to 8% of all primary brain tumors. An unusual case of an intrasellar schwannoma radiographically and clinically simulating a pituitary adenoma is reported. A 39-yr-old man presented a 10-month history of visual disturbance and decreased libido. Neurological examination showed poor visual acuity of both eyes with bitemporal hemianopsia. Computed tomography and magnetic resonance imaging showed a sellar tumor with suprasellar extension. Pituitary adenoma was considered as a preoperative diagnosis. The tumor was removed through a trans-sphenoidal approach. Microscopic examination of the tumor revealed schwannoma. (+info)
A case of multiple schwannomas of the trigeminal nerves, acoustic nerves, lower cranial nerves, brachial plexuses and spinal canal: schwannomatosis or neurofibromatosis?
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In most cases, while schwannoma is sporadically manifested as a single benign neoplasm, the presence of multiple schwannomas in one patient is usually indicative of neurofibromatosis 2. However, several recent reports have suggested that schwannomatosis itself may also be a distinct clinical entity. This study examines an extremely rare case of probable schwannomatosis associated with intracranial, intraspinal and peripheral involvements. A 63-year-old woman presented with a seven-year history of palpable lumps on both sides of the supraclavicular area and hearing impairment in both ears. On physical examination, no skin manifestations were evident. Facial sensory change, deafness in the left ear and decreased gag reflex were revealed by neurological examination. Magnetic resonance imaging revealed multiple lesions of the trigeminal nerves, acoustic nerves, lower cranial nerves, spinal accessory nerve, brachial plexuses, and spinal nerves. Pathological examination of tumors from the bilateral brachial plexuses, the spinal nerve in the T8 spinal position and the neck mass revealed benign schwannomas. Following is this patient case report of multiple schwannomas presenting with no skin manifestations of neurofibromatosis. (+info)
Two primary intracranial tumors of different histology: report of a case with a choroid plexus papilloma and a concurrent vestibular schwannoma in the cerebellopontine angle.
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A very rare case of multiple primary intracranial tumors is reported. A 41-year-old female patient was referred for surgery with a cerebellopontine angle (CPA) tumor. Medical history and MRI study showed typical findings of a right acoustic neuroma with a hydrocephalus. Neurological, dermatological, and ocular examinations revealed no evidence of neurofibromatosis. During surgery, a red-colored cauliflower like mass was found in the right CPA. The roof of the fourth ventricle could be seen through the lateral recess after removal of the tumor. Another mass, a 1.5-cm sized schwannoma protruding through the right internal auditory meatus, was removed by the transmeatal approach. Although the tumor masses were in contact and compressed against each other, there was a clear demarcation between them. Histological examination confirmed that the first mass was a typical choroid plexus papilloma with fibrovascular core, and that the second was a schwannoma. The patient recovered without any new neurological deficit. Result of a Medline search indicated that this rare combination of multiple primary tumors has not been reported previously. (+info)
Immunohistochemical staining for KIT (CD117) in soft tissue sarcomas is very limited in distribution.
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We performed immunohistochemical analysis for KIT in 365 soft tissue sarcomas. Most tumors evaluated were completely negative for KIT, including all cases of leiomyosarcoma, rhabdomyosarcoma, myxofibrosarcoma, liposarcoma, solitary fibrous tumor, synovial sarcoma, dermatofibrosarcoma protuberans, schwannoma, malignant peripheral nerve sheath tumor, clear cell sarcoma, low-grade endometrial stromal sarcoma, and follicular dendritic cell sarcoma. Tumors showing occasional immunoreactivity for KIT included extraskeletal myxoid chondrosarcoma (2/20), Ewing sarcoma/malignant primitive peripheral neuroectodermal tumor (4/20), melanotic schwannoma (3/5), metastatic melanoma (4/20), and angiosarcoma (5/20). In most cases, staining for KIT was focal. Rare tumor cells showing KIT positivity were identified in a small number of other tumors. This study demonstrates very limited expression of KIT in soft tissue tumors other than gastrointestinal stromal tumors and underscores the discriminatory value of KIT immunohistochemical analysis for differential diagnosis. As some of these findings differ markedly from previous reports, it is evident again that variations in immunohistochemical technique can lead to major discrepancies in positive staining. Since treatment eligibility for selective tyrosine kinase inhibitors such as STI571 hinges on positive immunostaining, standardization and reproducibility of meaningful results are critically important. (+info)
Presigmoid transpetrosal approach for the treatment of a large trochlear nerve schwannoma--case report.
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A 61-year-old man presented with a rare, large trochlear nerve schwannoma manifesting as left-sided weakness and hypesthesia, bilateral bulbar pareses, and trochlear nerve paresis persisting for 3 months. T1-weighted magnetic resonance imaging with gadolinium revealed an intensely enhanced, well-circumscribed lesion with multicystic formation occupying the prepontine and interpeduncular cisterns and compressing the pons and midbrain with greater extension to the right. The mass was completely removed through the presigmoid transpetrosal approach with preservation of the posterior cerebral, superior cerebellar, and basilar arteries and their branches. Neuroradiological examination after 3 years demonstrated no recurrence. Enlargement of a tumor in the cisternal portion is inclined to involve and/or encase the adjacent major arteries and their branches. The presigmoid transpetrosal approach is one of the best surgical routes to remove a large trochlear nerve schwannoma safely and completely. (+info)