Malignant meningeal melanoma

We report the case of an isolated pigmented lesion of the cerebellar tentorium which was initially interpreted as meningeal melanocytoma. The immunohistochemical study required as a result of a subsequent post-surgical recurrence prompted us to reconsider the early diagnosis in favour of malignant meningeal melanoma. On the basis of data in the literature, the possibility that the lesion may have been a durai melanoma is discussed.     

Malignant meningeal melanoma

We report the case of an isolated pigmented lesion of the cerebellar tentorium which was initially interpreted as meningeal melanocytoma. The immunohistochemical study required as a result of a subsequent post-surgical recurrence prompted us to reconsider the early diagnosis in favour of malignant meningeal melanoma. On the basis of data in the literature, the possibility that the lesion may have been a dural melanoma is discussed.     

Extradural thoracic meningeal cyst without spinal dysraphism causing adulthood myelopathy: Case illustration and review of the literature

Extradural spinal meningeal cysts are rare lesions in the adult spine and are an uncommon cause of neurologic deficits. We present the case of an adult who presented with myelopathic symptoms related to a dorsally based extradural thoracic meningeal cyst in the absence of any defect in the posterior spinal elements and no history of spinal dysraphism or trauma. We also performed a review of the literature to evaluate the surgical techniques for extradural meningeal cysts. Most thoracic cysts are intradural arachnoid cysts, yet this lesion is an extradural meningeal cyst, not an intradural arachnoid cyst. Because of the rarity of this lesion, its anatomic characterization can be difficult to conceptualize. An artist’s illustration helps illustrate the anatomic characteristics of this cyst and our surgical management.     

Slowly Progressive En-plaque Intracranial Sarcoidosis

A patient with suspected multiple sclerosis was studied with serial brain magnetic resonance imaging (MRI) over a period of 3 years before undergoing brain biopsy of an intracranial lesion, which proved to be meningeal sarcoidosis. This is the first report of enhanced and unenhanced MRI study of biopsy-proved intracranial meningeal sarcoidosis. Invasion of brain tissue seen on biopsy specimens could not be inferred from the MRI appearance.     

Neurosarcoidosis mimicking meningioma en-plaque: report of two cases and review of the literature

We describe two patients who presented with seizures and in whom imaging studies showed extra-axial disease which was simulating meningioma en-plaque. The diagnosis of neurosarcoidosis was obtained by meningeal biopsy. The clinical and MRI features of neurosarcoidosis presenting as an extra-axial mass lesion are reviewed. In cases in which clinical or radiological features place the diagnosis of meningioma in doubt, frozen section biopsy is advocated to avoid unwarranted excision of a lesion caused by sarcoidosis.     

An in vitro model of the inhibition of axon growth in the lesion scar formed after central nervous system injury

After central nervous system (CNS) injury, meningeal fibroblasts migrate in the lesion center to form a fibrotic scar which is surrounded by end feet of reactive astrocytes. The fibrotic scar expresses various axonal growth-inhibitory molecules and creates a major impediment for axonal regeneration. We developed an in vitro model of the scar using coculture of cerebral astrocytes and meningeal fibroblasts by adding transforming growth factor-β1 (TGF-β1), a potent fibrogenic factor. Addition of TGF-β1 to this coculture resulted in enhanced proliferation of fibroblasts and the formation of cell clusters which consisted of fibroblasts inside and surrounded by astrocytes. The cell cluster in culture densely accumulated the extracellular matrix molecules and axonal growth-inhibitory molecules similar to the fibrotic scar, and remarkably inhibited the neurite outgrowth of cerebellar neurons. Therefore, this culture system can be available to analyze the inhibitory property in the lesion site of CNS.     

Interactions between meningeal cells and astrocytes in vivo and in vitro.

At the interface between the meninges and the central nervous system there is a characteristic structure known as the glia limitans, consisting of many fine interdigitating astrocyte processes which contain both GFAP and vimentin, and a basal lamina. A similar structure is set up after brain injury where meningeal cells invade the lesion. We have experimentally put astrocytes and meningeal cells in contact with one another, both in vivo and in vitro, to see whether this results in the formation of a glia limitans. Cultured meningeal cells were injected into the hippocampus of adult rats, and from 1 to 12 weeks later brains were stained were stained for GFAP and vimentin. One week after injection there was a widespread astrocytic reaction stretching up to 2 mm from the injection, the cells being stained intensely for both GFAP and vimentin. Over the next 4-6 weeks this widespread reaction subsided, the only remaining vimentin stained astrocytes, apart from those at the normal glia limitans, being in contact with the injected meningeal cells, or with meningeal cells which had migrated into the injection needle track. In vitro a structure reminiscent of the glia limitans formed where patches of astrocytes abutted meningeal cells; the astrocytes formed a layer of fine interdigitating processes all running parallel to the interface between the two cell types, and there was heavy staining for laminin and fibronectin. We conclude that a glia limitans forms wherever astrocytes and meningeal cells come into contact.     

The behaviour of meningeal cells following glial cell transplantation into chemically-induced areas of demyelination in the CNS

Following transplantation of cultures of CNS glia containing leptomeningeal cells into ethidium bromide-induced demyelinating lesions, meningeal cells adopt either compacted or diffuse arrangements. The compacted arrangements involved no interactions with other cellular components of the remyelinating environment, and were particularly prominent following transplantation of cultures containing a high proportion of fibronectin-positive meningeal cells. The diffuse arrangements involved interactions with astrocytes, Schwann cells and endothelial cells, and contributed to a fragmented appearance of the lesion. Such observations indicate that meningeal cell contamination should be avoided when attempts are being made to repopulate glial-deficient lesions in the CNS by transplanting central glial cells, since their effect is to partition the glial environment.     

脑膜血管型神经梅毒病灶侧和对侧核磁共振灌注加权成像特征的研究

目的 研究脑膜血管型神经梅毒的影像学特征,指导与脑梗死的鉴别诊断.方法 对神经梅毒患者进行头部MRI平扫+增强、磁共振血管成像(Magnetic Resonance Angiography,MRA)、灌注加权成像(perfusion weighted imaging,PWI)和磁敏感加权成像(Susceptibilit...     

The diagnostic difficulties of meningeal and intracerebral plasma cell granulomas—presentation of three cases

Meningeal and intracerebral plasma cell granulomas are uncommon inflammatory lesions of unknown etiology. In this paper the diagnostic difficulties in two patients with meningeal plasma cell granuloma and one patient with intracerebral plasma cell granuloma are described. The first patient had an intracranial extra-axial lesion, which was first diagnosed as a meningioma. One and a half years later she underwent a second resection for recurrent tumor growth and the diagnosis of a meningeal plasma cell granuloma was made. The second patient was treated for a central nervous system B-cell lymphoma but proved to have an intracerebral plasma cell granuloma in retrospect 11 years later. In the third patient tuberculous meningitis was considered to be the most likely diagnosis because infratentorial contrast-enhanced thickened meninges (pachymeningitis) were found together with a high protein level in the cerebrospinal fluid and a positive Mantoux test. However, pathological examination of an extra-axial, cervical lesion that was operated upon revealed a meningeal plasma cell granuloma. These cases show the importance of diagnosing a meningeal or intracerebral plasma cell granuloma correctly, since it has both therapeutical and prognostic implications.     

Diffuse leptomeningeal spread of pleomorphic xanthoastrocytoma

Diffuse meningeal spread and dural infiltration by pleomorphic xanthoastrocytoma occurring after initial diagnosis of a left frontotemporal lesion is reported. The unusual pattern of spread and aggressive course for a pleomorphic xanthoastrocytoma are discussed.     

MRI and pathological findings of rheumatoid meningitis

Rheumatoid meningitis (RM) is one of the most severe complications of rheumatoid arthritis. The mortality rate of RM is relatively high and diagnosis can be difficult. We present an 80-year-old woman who was diagnosed with microscopic findings of RM after analysis of biopsy specimens taken from a brain lesion. MRI scanning revealed meningeal enhancement in the brain, and the pathological findings were those of meningeal lymphocytic infiltration, vasculitis and rheumatoid nodules. RM is a treatable disease and in this patient RM was diagnosed on the basis of biopsy findings.     

Extracranial metastasizing solitary fibrous tumors (SFT) of meninges: Histopathological features of a case with long‐term follow‐up

Extrapleural solitary fibrous tumors are uncommon mesenchymal neoplasms frequently observed in middle‐aged adults and are classified, according to the WHO classification of soft tissue tumors, as part of the hemangiopericytoma tumor group. However, these two entities remain separated in the WHO classification of tumors of the central nervous system. In fact, meningeal solitary fibrous tumors are believed to be benign lesion and only in a minority of cases local relapses have been described, although detailed survival clinical studies on solitary fibrous tumors of meninges are rare. In contrast to hemangiopericytoma, which frequently shows distant extracranial metastases, such an event is exceptional in patients with meningeal solitary fibrous tumors and has been clinically reported in a handful of cases only and their histopathological features have not been investigated in detail. In this report, we describe the detailed clinico‐pathological features of a meningeal solitary fibrous tumor presenting during a 17‐year follow‐up period, multiple intra‐, extracranial relapses and lung metastases.     

Meningeal cell-derived semaphorin 3A inhibits neurite outgrowth

The neural scar that forms after injury to the mammalian central nervous system is a barrier to sprouting and regenerating axons. In addition to reactive astrocytes that are present throughout the lesion site, leptomeningeal fibroblasts invade the lesion core. When isolated in vitro, these cells form a very poor substrate for growing neurites, even more so than reactive astrocytes. Nevertheless the molecular mechanisms involved in this growth inhibition are not well understood. Semaphorins have been reported to be upregulated in meningeal cells (MCs) on mechanical injury to the brain and spinal cord. In the present study, we show that Sema3A mRNA and active protein are produced by cultured meningeal cells. A protein extract from these cells induces the collapse of embryonic dorsal root ganglion (DRG) growth cones. This collapsing activity is partially blocked by neuropilin-1 antibodies and is absent in meningeal cells derived from Sema3A-knockout mice. In addition to growth cone collapse, recombinant Sema3A but not Sema3C inhibits neurite outgrowth of embryonic DRGs. Consistent with this result we find that the inhibitory effect of meningeal cells on neurite outgrowth is partially overcome on Sema3A-deficient MCs. Furthermore we show that the inhibitory effect of MC-derived Sema3A on neurite outgrowth is modulated by nerve growth factor. Our results show that Sema3A, a chemorepellent during nervous system development, is a major neurite growth-inhibitory molecule in meningeal fibroblasts and is therefore likely to contribute to the inhibitory properties of the neural scar.     

Solitary plasmocytoma of the calvarium

We report a case of 54 year old patient harboring a solitary painless mass of the calvarium. There was a well-defined biparietal lytic lesion on plain skull radiographics. Computed tomography showed a large hyperdense lesion. This lesion was extraaxial and nearly isointense with gray matter on T1 and T2-weighted MR images, and diffusely enhanced after gadolinium injection. Angiography showed hyperovascularity supplied by middle meningeal and superficial temporal arteries. Imaging study bore some similarities to meningioma. A large extra-axial mass with an important lytic lesion should have led to the diagnosis of plasmocytoma.     

Primary Diffuse Leptomeningeal Gliomatosis with Signs of Increased Intracranial Pressure and Progressive Meningeal Enhancement on MRI

A 21-year-old woman presented with a 5-month history of meningeal signs and evidence of intracranial hypertension and, as shown by magnetic resonance imaging (MRI), progressively more extensive meningeal enhancement, particularly within the spinal canal. Autopsy disclosed the presence of primary diffuse leptomeningeal gliomatosis with spinal cord predominance, possibly arising within heterotopic leptomeningeal glial tissue in the cervical region. No parenchymal primary lesion was identified. MRI with gadolinium appears to be the imaging modality of choice for the early detection of primary diffuse leptomeningeal neoplasia.     

Aneurisma gigante no traumático de la arteria meníngea media. A propósito de un caso y revisión de la literatura

A case of a non-traumatic giant aneurysm of the middle meningeal artery is presented in a 59-year-old patient with a history of liver transplantation, liver cirrhosis and hepatocarcinoma, chronic renal disease, hypertension and chronic bronchitis who presented with tonic-clonic seizures. CT and MRI showed a lesion suggestive of metastasis without ruling out a glial type tumor. He was operated through a left FT craniotomy. During the surgery there was an arterial hemorrhage. The histological sample oriented toward an aneurysmal origin that was confirmed with ARM and angiography. A second intervention allowed the removal of a giant middle meningeal aneurysm partially thrombosed. Aneurysms of the middle meningeal artery are rare and generally present a traumatic history. No case of giant aneurysm has been found in the medical literature.     

Meningeal extramedullary haematopoiesis mimicking subdural hematoma.

Extramedullary haematopoiesis is a compensatory phenomenon in diseases where erythrocyte production is diminished or destruction is accelerated. The authors describe a rare case of meningeal extramedullary haematopoiesis mimicking subdural hematoma. CT scan revealed a hyperdense subdural lesion at the right frontal region following head injury. The patient was operated on and the pathological examination of the subdural lesion showed extramedullary haematopoiesis.     

颅前窝底硬脑膜动静脉瘘的影像学分析及治疗策略

目的探讨颅前窝底硬脑膜动静脉瘘的影像学特点,并根据其而采取不同治疗方式。方法回顾性分析13例颅前窝底硬脑膜动静脉瘘病人的临床资料,病变均通过双侧眼动脉或筛前动脉供血,其中脑膜中动脉前支也参与供血7例。采用开颅手术9例,血管内治疗4例。并分析影像学特征对选择治疗方式的影响。结果术后DSA复查示所有病人的动静脉瘘均消失,均无手术并发症,术后症状逐渐好转。术后1年,DSA复查7例,均未复发。结论开颅手术治疗颅前窝底硬脑膜动静脉瘘是安全、有效的方法,对明确有硬脑膜中动脉前支供血的病变,也可行介入栓塞治疗。     

脑膜癌病的临床特征及误诊原因分析

目的 分析11例脑膜癌病的临床特征及误诊原因。方法 对2002年7月-2003年12月收治的11例经脑脊液细胞学证实的脑膜癌病患的临床资料进行分析。结果 首发症状多以头痛、呕吐为主，亦可有视觉障碍、复视、眼睑闭合无力、口角歪斜以及发作性上背部疼痛，可伴脑神经和脊神经损害及脑膜刺激征；头部CT及MRI均无异常发现。脑脊液检查颅内压均不同程度增高(200-400mmH2O)，其中8例细胞数、蛋白升高，糖、氯化物下降；细胞学检查均发现癌细胞，形态与原发肿瘤相似，来源于肺癌5例、乳腺癌3例、胃癌1例、卵巢癌1例、血液系统恶性淋巴瘤1例。其中5例于发现原发肿瘤之前即有神经系统症状。11例患中6例病情恶化自动出院，2例院内死亡，3例经对症治疗症状缓解出院。结论 对以头痛、呕吐发病伴脑神经、脊神经受损，并出现脑膜刺激征和颅内压增高，头部CT及MRI无明显异常，应考虑脑膜癌病的可能，及早行全身检查寻找原发病灶，以脑脊液发现癌细胞为确诊依据。