Intracranial solitary fibrous tumor: Imaging findings

Objective

To study the neuroimaging features of intracranial solitary fibrous tumors (ISFTs).

Materials and methods

Retrospective study of neuroimaging features of 9 consecutive histopathologically proven ISFT cases. Location, size, shape, density, signal intensity and gadolinium uptake were studied at CT and MRI. Data collected from diffusion-weighted imaging (DWI) (3 patients), perfusion imaging and MR spectroscopy (2 patients), and DSA (4 patients) were also analyzed.

Results

The tumors most frequently arose from the intracranial meninges (7/9), while the other lesions were intraventricular. Tumor size ranged from 2.5 to 10 cm (mean = 6.6 cm). They presented multilobular shape in 6/9 patients. Most ISFTs were heterogeneous (7/9) with areas of low T2 signal intensity that strongly enhanced after gadolinium administration (6/8). Erosion of the skull was present in about half of the cases (4/9). Components with decreased apparent diffusion coefficient were seen in 2/3 ISFTs on DWI. Spectroscopy revealed elevated peaks of choline and myo-inositol. MR perfusion showed features of hyperperfusion.

Conclusion

ISFT should be considered in cases of extra-axial, supratentorial, heterogeneous, hypervascular tumor. Areas of low T2 signal intensity that strongly enhance after gadolinium injection are suggestive of this diagnosis. Restricted diffusion and elevated peak of myo-inositol may be additional valuable features.     

Extramedullary hematopoiesis involving the central nervous system and surrounding structures

Extramedullary hematopoiesis in central nervous system is a rare condition that can present in association with hematologic conditions. In this single-center retrospective study from 1988 to 2010, we identified 8 cases of extramedullary hematopoiesis involving the central nervous system or meninges. Most were incidental autopsy findings, usually microscopic collections of cells in the meninges or around blood vessels in the brain of infants (4 cases; age, 10 days to 5 months), in 1 young child (age, 6.5 years with anemia), and 1 elderly adult (age, 81 years with end-stage idiopathic myelofibrosis). Two individuals (both with polycythemia rubra vera) presented with symptomatic intracranial or spinal canal lesions (age, 67 and 68 years). Mixed populations of immature hematopoietic cells were identified by characteristic morphology and appropriate immunohistochemistry. The precise pathogenesis of extramedullary hematopoiesis in central nervous system is unknown. In infants, extramedullary hematopoiesis is unlikely to be pathologic and most likely represents a resolving fetal state. The older children and adults with incidental or symptomatic extramedullary hematopoiesis usually have some underlying hematologic condition, which should be sought if not already recognized.     

Hippocampus/amygdala alterations, loss of heparan sulfates, fractones and ventricle wall reduction in adult BTBR T+ tf/J mice, animal model for autism

Multiple studies converge to implicate alterations of the hippocampus and amygdala in the pathology of autism. We have previously reported anatomical alterations of the meninges, vasculature and fractones, the specialized extracellular matrix (ECM) of the subventricular zone, in the forebrain of adult BTBR T+ tf/J mice, animal model for autism. Here, we used bisbenzidine cell nucleus staining and dual immunofluorescence histochemistry for laminin and N-sulfated heparan sulfate proteoglycans (NS-HSPG) to examine a series of brain sections containing the amygdala and hippocampus in the adult BTBR T+ tf/j mouse. We observed an excessive separation of the two hippocampi, a modified trajectory of the meninges leading to a shrunken choroid plexus in the lateral ventricle, a shorter granular layer of the dentate gyrus, and a reduced size of the amygdala nuclei. The lateral ventricle near the amygdala, and the third ventricle were shrunken. The number and size of fractones, and their immunoreactivity for NS-HSPG, were reduced throughout the third and lateral ventricles walls. Enlarged blood vessels were found at the endopiriform cortex/amygdala interface. These results show anatomical alterations of the hippocampal/amygdala that are associated with defects of the choroid plexus/ventricular system and the ECM in the BTBR T+ TF/J mouse. Similar alterations of the hippocampus/amygdala axis in humans with autism to these observed in BTBR T+ tf/J mice make this animal model highly valuable for the study of autism. Moreover, the meningo/vascular and ECM alterations in BTBR T+ Tf/J mice suggest a possible role of the brain connective tissue in autism.     

非脑膜瘤脑膜病变的MRI表现及强化模式

目的 分析不同脑膜病变的MR成像表现，探讨MRI尤其是脑膜强化模式对各种脑膜病变的诊断及鉴别诊断价值。方法 临床资料完整的脑膜病变61例，其中感染性脑膜炎27例；非感染性脑膜炎4例，包括嗜酸性肉芽肿2例，wegener肉芽肿l例，病因不明l例；脑膜转移瘤12例；脑膜淋巴瘤2例；脑梗死8例；手术后脑膜改变8例。MR常规扫描后均行钆喷替酸葡甲胺(Gd-DTPA)增强扫描。结果 (1)MR平扫：异常脑膜改变仅3例，其中脑膜增厚l例，脑膜结节2例。(2)MR增强扫描：61例呈3种脑膜强化模式，分别为I型、Ⅱ型、Ⅲ型强化模式。I型强化模式即硬脑膜-蛛网膜强化，有19例；Ⅱ型强化模式即蛛网膜-软脑膜强化，有32例；Ⅲ型强化模式即全脑膜强化(包括硬脑膜及软脑膜)，有10例。结论 不同脑膜病变MR成像表现尤其是增强模式有一定特点。各种脑膜病变增强模式对于鉴别各种脑膜病变，发现病变细节，提示临床诊疗均有明显意义。     

Meningeal involvement in Behçet's disease: MRI

Behçet's disease is a multisystem disease that involves the central nervous system up to half of cases. Presentation with neurologic symptoms occurs in 5 % of cases and cerebral venous thrombosis is one of its major manifestations. A feature not previously reported is progressive meningeal thickening with involvement of both optic nerves. We report a patient with cerebral venous thrombosis, meningeal thickening and contrast enhancement on MRI. This patient had two other unusual features: positive antineutrophil cytoplasmic antibodies and later development of central diabetes insipidus.     

基于QST分型的颅咽管瘤与第三脑室底脑膜层次的关系

目的探索基于QST分型的、累及第三脑室底的颅咽管瘤与第三脑室底脑膜层次的关系及临床意义。方法回顾性分析2018年1月至2019年10月南方医科大学南方医院神经外科在神经内镜下行肿瘤全切除术治疗累及第三脑室底的原发性颅咽管瘤患者的临床资料(共17例,其中Q型6例,S型3例,T型8例),所有患者术中均留取肿瘤组织标本。正常鞍区标本来源于同期该院行人工引产或自然流产的胎儿(8例)。对以上标本进行苏木素-伊红(HE)和免疫荧光双标染色,应用波形蛋白抗体标记硬脑膜,Ⅰ型胶原蛋白抗体标记蛛网膜,胶质纤维酸性蛋白抗体和层粘连蛋白抗体标记软脑膜,以CK18抗体标记腺垂体,以CK5/6抗体标记颅咽管瘤。观察胎儿脑组织标本的脑膜染色情况以及不同QST分型的颅咽管瘤组织与第三脑室底脑膜的层次关系。结果8例胎儿标本均成功标记硬脑膜、蛛网膜、软脑膜。颅咽管瘤标本HE染色及免疫荧光双标染色结果显示,所有Q型肿瘤(6/6)与第三脑室底之间存在硬脑膜(鞍膈);所有S型肿瘤(3/3)与第三脑室底之间存在蛛网膜和软脑膜;T型肿瘤与第三脑室底之间存在3种病理学形态关系,分别命名为卯榫样、地幔样及护城河样关系,所有T型肿瘤(8/8)与第三脑室底之间有软脑膜分隔,但在肿瘤起源点处,软脑膜可逐渐消失。当肿瘤极度挤压第三脑室空间时,第三脑室室管膜仍可保持完整。结论不同QST分型的颅咽管瘤均可累及第三脑室底,且与第三脑室底之间存在不同的脑膜层次;这些脑膜层次是手术安全切除累及第三脑室底的颅咽管瘤的天然屏障。     

Intradural extramedullary spinal canal secondary neoplasms: MR findings in 30 patients

The purpose of this study was to describe magnetic resonance findings of intradural spinal canal secondaries and to select the best way of investigating this condition. Thirty patients with a known malignancy [breast carcinoma (n = 14), lung carcinoma (n = 10), other sites (n = 6)] and unexplained neurologic signs were studied with pre- and post-contrast T1-weighted images and T2-weighted images. Cerebrospinal fluid cytology was available in 16 patients and positive in 11 patients. In all the patients, post-contrast T1-weighted images demonstrated abnormal enhanced lesions. Most of them were nodular, located on the conus medullaris and the cauda equina. Few lesions appeared at the thoracic or cervical levels, as nodular or thin areas of enhancement. Pre-contrast T1-weighted sequences failed or were equivocal to detect the lesions. Eighteen of 30 patients had cerebral metastases. Fourteen had osseous metastases. In conclusion, post-contrast T1-weighted sequence is the optimal modality for the diagnostic of intradural spinal canal metastases. Axial and coronal images may be a useful adjunct to precise anatomic changes. T1-weighted and T2-weighted sequences remain necessary when further information is expected on vertebra or soft tissue. Received 25 September 1997; Revision received 29 December 1997; Accepted 5 January 1998     

Pial involvement in Wegener's granulomatosis shown on MRI

Involvement of the brain and meninges is rare in Wegener's granulomatosis (WG); it has been reported in 1.2–8 % of patients. Meningeal involvement in WG has been reported in imaging as being confined to the duramater, and is thought to represent granulomatous infiltration. We present a case of WG with abnormal pial enhancement and involvement of the perivascular spaces on MRI, pathologically proven to represent granulomatous infiltration due to the primary disease rather than to infection. Received: 27 November 1998 Accepted: 25 March 1999     

Vitamin D target systems in the brain of the green lizard Anolis carolinensis

Autoradiographic mapping criteria were employed to identify and localize specific high affinity binding sites (receptors) for the steroid hormone 1,25-dihydroxyvitamin D₃ (1,25-D₃) in the brain of Anolis carolinensis. In female and male lizards binding of tritiated 1,25-D₃ occurred in identical regions of the fore-, mid-, and hindbrain, similar to findings in other species. There was a band of intensely labeled neurons forming a continuum from the n. accumbens, n. striae terminalis, the striatum, and extending into the amygdala. Target areas with high to intermediate labeling intensities were present in many other regions of the brain and single, small target cells were found throughout the organ. Some cells in the pituitary and pineal were labeled and also cells associated with the meninges, choroid plexuses and ependyma. The differential labeling suggests the existence of different 1,25-D₃-responsive systems. One of the conspicuous high capacity-high affinity systems is found in the n. accumbens-n. striae terminalis and the amygdala. Most of the cerebral target regions for vitamin D correspond to those known for gonadal steroids, and the seasonal steroid 1,25-D₃ may therefore act in conjunction with gonadal steroids in this seasonally breeding reptile.