1/15. Calcified vestibular schwannoma with unusual histological characteristics - positive immunoreactivity for CD-34 antigen.Calcification in vestibular schwannoma is extremely rare. A 36-year-old man presented with a history of decreased hearing on the left since childhood. Computed tomography showed a left cerebellopontine angle lesion protruding into the porus acousticus and enlarging the internal auditory meatus, with significant deposits of calcification. Histological and immunohistochemical examination, including staining for CD-34, a myeloid progenitor cell antigen, found highly degenerated schwannoma with collagen-rich tissue, calcification, formation of bone, abnormal vessels of various sizes, and old haemorrhage with marked haemosiderin-laden macrophages. Most of the surgical specimen was sclerotic collagenous tissue containing sparse spindle-shaped cells which formed approximately 90% of the total specimen. However, the spindle-shaped cells were partly concentrated into islands forming the cellular part (approximately 10% of the total). The spindle-shaped cells in both parts showed almost typical immunohistochemical characteristics of schwannoma. However, many spindle-shaped cells in only the sclerotic part were positive for CD-34, which is widely used for the diagnosis of solitary fibrous tumours. cerebellopontine angle tumour showing fibromatous tissue, including calcification, may contain foci of typical schwannoma. Careful histological examination with detailed immunohistochemical staining is required for the correct diagnosis. In particular, spindle-shaped cells occasionally show positive immunoreactivity for CD-34 antigen in the areas of degenerated and calcified schwannoma characteristic of our case.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
2/15. Distal anterior inferior cerebellar artery syndrome after acoustic neuroma surgery.OBJECTIVE: To define a clinicopathologic syndrome associated with persistent cerebellar dysfunction after acoustic neuroma (AN) excision. STUDY DESIGN: Case series derived from radiographic and clinical chart review. SETTING: Tertiary referral center. patients: In 12 patients with AN, persistent cerebellar dysfunction developed after AN removal. Each case demonstrated abnormality in the ipsilateral cerebellar peduncle on postoperative magnetic resonance imaging. MAIN OUTCOME MEASURES: Cerebellar function and ambulatory status over the first postoperative year. RESULTS: On magnetic resonance imaging scans, the extent of cerebellar peduncle infarcts was variable. It ranged from focal brain injury (<1 cm) involving only one third of the peduncle to diffuse defects (>2 cm) spanning the full thickness of the peduncle. Peduncular infarcts were associated with large tumor size (average 3.8 cm, range 2.0-5.5 cm diameter). The long-term functional outcomes (>1 yr) varied. Dysmetria was unchanged or improved in over half of the patients (6 of 11 patients). gait recovered to normal or to preoperative levels in 5 patients. In the 6 patients with persistent impaired mobility, 2 had mild gait disturbance, 3 required regular use of a cane, and 1 has been dependent on a walker. One patient had sustained mild motor weakness. Three of 11 patients remained dependent on others for activities of daily living. CONCLUSIONS: Peduncle injury most likely stems from interruption of distal branches of the anterior inferior cerebellar artery (AICA). These small vessels are intimately related to the capsule of the tumor and may supply both the neoplasm and the brain parenchyma. It has long been recognized that interruption of the proximal segment of the AICA results in severe injury to the pons, with devastating neurologic sequelae. A limited AICA syndrome caused by loss of its distal ramifications seems a more plausible explanation for peduncular infarction than either venous insufficiency or direct surgical trauma.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
3/15. Neurovascularized free short head of the biceps femoris muscle transfer for one-stage reanimation of facial paralysis.The single-stage technique for cross-face reanimation of the paralyzed face without nerve graft is an improvement over the two-stage procedure because it results in early reinnervation of the transferred muscle and shortens the period of rehabilitation. On the basis of an anatomic investigation, the short head of the biceps femoris muscle with attached lateral intermuscular septum of the thigh was identified as a new candidate for microneurovascular free muscle transfer. The authors performed one-stage transfer of the short head of the biceps femoris muscle with a long motor nerve for reanimation of established facial paralysis in seven patients. The dominant nutrient vessels of the short head were the profunda perforators (second or third) in six patients and the direct branches from the popliteal vessels in one patient. The recipient vessels were the facial vessels in all cases. The length of the motor nerve of the short head ranged from 10 to 16 cm, and it was sutured directly to several zygomatic and buccal branches of the contralateral facial nerve in six patients. One patient required an interpositional nerve graft of 3 cm to reach the suitable facial nerve branches on the intact side. The period required for initial voluntary movement of the transferred muscles ranged from 4 to 10 months after the procedures. The period of postoperative follow-up ranged from 5 to 42 months. Transfer of the vascularized innervated short head of the biceps femoris muscle is thought to be an alternative for one-stage reconstruction of the paralyzed face because of the reliable vascular anatomy of the muscle and because it allows two teams to operate together without the need to reposition the patient. The nerve to the short head of the biceps femoris enters the side opposite the vascular pedicle of the muscle belly, and this unique relationship between the vascular pedicle and the motor nerve is anatomically suitable for one-stage reconstruction of the paralyzed face. As much as to 16 cm of the nerve can be harvested, and the nerve is long enough to reach the contralateral intact facial nerve in almost all cases. The lateral intermuscular septum, which is attached to the short head, provides "anchor/suture-bearing" tissue, allowing reliable fixations to the zygoma and the upper and lower lips to be achieved. In addition, the scar and deformity of the donor site are acceptable, and loss of this muscle does not result in donor-site dysfunction.- - - - - - - - - - ranking = 4keywords = vessel (Clic here for more details about this article) |
4/15. Multicystic acoustic schwannoma with intratumoral hemorrhage: a report of two cases.We encountered two multicystic acoustic schwannomas with intratumoral hemorrhage. The radiological appearance in each case was similar to that obtained with CT and MRI. From a histological perspective, in each case we observed hypervascularity with thin-walled, dilated vessels in clusters and hemosiderin depositions around the dilated vessels.- - - - - - - - - - ranking = 2keywords = vessel (Clic here for more details about this article) |
5/15. Hemorrhagic acoustic schwannoma: radiological and histopathological findings.A 49-year-old man on anticoagulation treatment with phenprocoumon presented with acute right sided 7th and 8th cranial nerve palsy, acute hearing loss, headache, vertigo, and vomiting. CT and MRI revealed a cerebellopontine angle tumor 15mm in diameter and acute intratumoral hematoma. A cellular schwannoma composed predominantly of Antoni A tissue with dilated thin-walled vessels, surrounded by old hemorrhage with hemosiderin-laden macrophages was found histologically.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
6/15. Primary melanocytic tumor of the cerebellopontine angle mimicking a vestibular schwannoma: case report.OBJECTIVE: The majority of tumors of the cerebellopontine angle (CPA) are benign. We report the case of a primary malignant melanoma of the CPA that mimicked a vestibular schwannoma (acoustic neuroma). We discuss the differential diagnosis and prognosis of melanotic lesions at this location. CLINICAL PRESENTATION: A 49-year-old man presented with a 7-year history of unilateral deafness and a several month history of imbalance, intractable nausea and vomiting, as well as weight loss. A neurological work-up revealed a large tumor in the left CPA radiographically diagnosed as a vestibular schwannoma. INTERVENTION: A translabyrinthine approach revealed a pigmented, vascular neoplasm encasing vessels and cranial nerves of the left CPA. The tumor was subtotally resected, and a histopathological diagnosis of melanoma was made. The patient had no history of cutaneous melanoma and no other site of disease was ever discovered. CONCLUSION: This case most likely represents primary melanoma of the central nervous system that mimicked a vestibular schwannoma. The differential diagnosis of melanotic lesions of the CPA is discussed as are the prognostic implications of each diagnosis.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
7/15. Massive hemorrhage in acoustic neurinoma after minor head trauma--case report.Massive hemorrhage within an intracranial neurinoma occurs rarely. The authors describe a 62-year-old female with intratumoral bleeding which led to the discovery of an acoustic neurinoma. She developed a gait disturbance after a minor head injury. A computed tomographic scan obtained 2 months later demonstrated multiple high-density areas in the anterior portion of the left cerebellopontine angle. Preoperative diagnosis was acoustic neurinoma. The tumor had multiple cysts which contained a mixture of xanthochromic fluid and old, brownish hematomas, and was successfully removed. The intratumoral hemorrhage is thought to have resulted from traumatic rupture of the dilated vessels, although the trauma was slight. This is the first reported case of an acoustic neurinoma discovered through treatment for intratumoral hemorrhage occurring after a minor head injury.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
8/15. Acoustic neurinoma with intratumoral bleeding.The Authors present a case of acoustic neurinoma which has caused intratumoral bleeding. Although acoustic neurinomas are about 8-10% of all intracranial tumors there are only few cases about acoustic neurinomas causing hemorrhage. Pathologic changes of intratumoral vessels in tumors larger than 2 cm were considered to be a cause of the hemorrhage. This rare pathology must be remembered as one of the causes of the intracranial bleeding.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
9/15. Acoustic neurinoma presenting as intratumoral bleeding.The authors report a case of acoustic neurinoma presenting as intratumoral bleeding. This is the tenth reported occurrence. The literature is reviewed. All cases that have been reported have appeared with sudden onset of headache, vomiting, and decreased levels of consciousness. aneurysm rupture, an arteriovenous malformation, or other vascular anomalies are suspected first. Preexisting unilateral hearing impairment is a valuable clue to differential diagnosis. Contrast-enhanced computed tomographic scans and cerebral angiograms are important tools for correct diagnosis. The tumor size (greater than 2 cm) and the thin, dilated vessels within the tumor are considered as pathogenetic factors for bleeding. When neurological status is not stable, placement of a ventriculoperitoneal shunt followed by urgent extirpation of the tumor is indicated.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
10/15. Supratentorial intracerebral hemorrhage after posterior fossa operation.Three cases of supratentorial intracerebral hemorrhage after posterior fossa operation are described, and nine other cases reported in the literature are reviewed. The possible causes are discussed, but in eight cases no definite cause could be found. All eight patients were operated on in the sitting position, and all had hematomas in the subcortical white matter. A possible cause might be changes in intracranial dynamics in the sitting position with disruption of subcortical veins. Other authors mention the possibility of occlusion of carotid or vertebral vessels in the neck by improper positioning of the head leading to intraoperative infarction and to hemorrhage within the infarcted brain after repositioning of the patient. With the patient in a lateral or semilateral position, this complication should be preventable.- - - - - - - - - - ranking = 1keywords = vessel (Clic here for more details about this article) |
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