脑肿瘤的病理和影像学特征(精品课件)

1、脑肿瘤的病理和影像学特征1脑外肿瘤的MR征象提示征象周边、广基紧贴颅骨邻近颅骨改变邻近脑膜强化邻近脑组织受推移远离颅骨肯定征象脑组织和病灶间存在脑脊液间隙脑组织和病灶间可见血管间隔肿块和白质（水肿）间可见皮层结构 硬（脑）膜外肿块与脑组织间可见硬膜结构234低级星形细胞瘤 大体病理受侵脑组织肿胀，扭曲变形；浸润肿块灰白质面模糊；大体上可以为局限性的，也可弥漫地浸润邻近脑组织；偶尔呈囊性，可见钙化镜下病理新生的分化较好的纤维型星形细胞和肥胖型星形细胞；组织结构疏松，常有微囊变的肿瘤基质；中度增生的肿瘤细胞实质；偶尔出现核不典型变；缺乏有丝分裂或罕有；没有微血管的增生及坏死组织分型：纤维型、肥胖型

2、、原浆型分期及分级标准：WHO级56CT表现平扫：境界不清的均匀的低/等密度肿块；20%有钙化；囊变罕见增强：无强化（若有强化则提示局部恶性变)MRI表现信号强度：T1WI低信号，T2WI及FLAIR高信号。钙化、囊变少见。出血、瘤周水肿罕见。可扩散到邻近脑组织可表现为局限性的，但可浸润邻近脑组织。通常无强化；强化则提示向高度恶性进展 。DWI：通常缺乏限制性弥散 MRS：高Cho，低NAA，高MI/Cr(0.850.25） 78间变型星形细胞瘤 大体病理浸润性肿块，边界不清。结构可以比较稀疏但侵袭邻近组织。囊变，出血不常见镜下病理结构更密实。显著的有丝分裂，核不典型变核浆比升高, 坏死及微血

3、管增生。可出现肥胖细胞的变异WHO 级9CT表现平扫：低密度肿块；钙化罕见增强：大多数不强化MRI表现信号强度：T1WI为混杂等、低信号，T2WI、FLAIR为混杂的高信号。钙化、出血、囊变罕见。增强扫描：通常无强化，可有局灶性、结节状、均一、斑片状强化。任何强化都应提示胶质母细胞瘤的可能。MRS：Cho/Cr升高，NAA降低 1011多形性胶质母细胞瘤 大体病理绝大多数多形性胶质母细胞瘤血供丰富。大体上可见出血；坏死核心周围环绕着灰红色的肿瘤组织镜下病理坏死，微血管增生星形细胞形态多样显著的核不典型变大量的有丝分裂分期与分级：WHO 级12CT表现平扫：周围等密度，中心低密度，出血，钙化罕见

4、。增强：显著，不均匀，不规则强化MRI表现信号强度（通常为混杂性）：T1WI：等、低信号（可能有亚急性出血）；T2WI/FLAIR：高信号伴瘤周水肿，肿瘤的边界超过异常信号之外动态对比增强MRI能反映微血管的通透性，有助于肿瘤的分级诊断13DSA：血供丰富，显著的肿瘤染色，动静脉分流MRS：NAA、MI降低，Cho/Cr、乳酸/水升高DWI：比低度恶性的星型细胞瘤的ADC测量值低PWI：可鉴别GBM与低度恶性星型细胞瘤（GBM的rCBV高）1415大脑胶质瘤病 大体病理分两种类型：1、肿瘤在脑组织上过度生长或扩展，但没有明确的肿块；2、弥漫性病灶局限性肿块镜下病理胶质细胞拉长，核深染，有丝分裂

5、变异；胶质细胞通常平行排列；沿有髓鞘的神经纤维弥漫性浸润；微血管增生，缺乏坏死；GFAP；细胞成分为主型的偶尔是少突胶质细胞瘤分期与分级：通常WHO 级 16CT表现 平扫：边界不清，非对称，低密度增强：通常不强化MRI表现T1WI：等/低信号T2WI/FLAIR：高信号轻度强化，局灶性强化可代表恶性胶质瘤MRS：Cho/Cr、Cho/NAA升高，乳酸，出现脂质峰17大体病理境界清楚，质软、囊性、灰色肿块。无包膜，质地较硬，常伴囊变，有时囊变部分可大大超过瘤体本身，而将瘤体推向一侧形成壁结节镜下病理肿瘤细胞多细长，自细胞一端或两端发出毛发丝状纤维突起和嗜酸小体分期与分级：WHO 级毛细胞型星形

6、细胞瘤18CT表现平扫：小脑蚓部或小脑半球稀疏的囊/实性肿块；无瘤周水肿；低/等密度；20有钙化增强：95强化（强化形式各异）MRI表现实性或结节在T1WI上低/等信号，T2WI上高信号。囊性成分在T2WI上高信号，FLAIR上不被抑制。不均匀强化。MRS：高Cho，低NAA，高乳酸ADULT PATIENTS WITH SUPRATENTORIAL PILOCYTIC ASTROCYTOMAS:A PROSPECTIVE MULTICENTER CLINICAL TRIAL. PAUL D. BROWN et al.Int. J. Radiation Oncology Biol. Phys.

7、, Vol. 58, No. 4, 11531160, 20041920PAUL D. BROWN et al. ADULT PATIENTS WITH SUPRATENTORIAL PILOCYTIC ASTROCYTOMAS:A PROSPECTIVE MULTICENTER CLINICAL TRIAL. I. J. Radiation Oncology Biology Physics Volume 58, Number 4, 2004 In adult:The temporal lobe was the most commonly involved site Malignant tra

8、nsformation is rare Favorable prognosis of adults with pilocytic astrocytomas with regard to survival and neurologic function. With an estimated 10-year survival rate of 95% Radiologic therapy need not be offered to adults with supra- tentorial pilocytic astrocytomas who have undergone gross or subt

9、otal resection21室管膜下巨细胞型星形细胞瘤多为结节性硬化伴发错构瘤恶变大体病理边界清楚的分叶状肿块。常见钙化、囊变、丰富的血管镜下病理典型者呈双核或多核星形细胞，常见囊变、坏死，可见大的肿胀星形细胞胞质呈玻璃样嗜酸性，分化良好，有丝分裂罕见分期与分级：WHO将其归为级2223CT表现平扫：常见一侧侧脑室或二侧侧脑室扩大, 肿瘤多呈低等混合密度，可见钙化和囊变也可见沿纹状体丘脑沟的室管膜下错构结节，该结节呈等密度，伴钙化或不伴钙化增强：可见明显不均匀强化动态扫描显示达峰值时间缩短，密度下降期延长MRI表现平扫T1WI为低等混合信号，T2WI为等或高信号增强后常有明显不均匀强化24

10、Shunji Nishio et al. Subependymal giant cell astrocytoma: clinicaland neuroimaging features of four cases. Journal of Clinical Neuroscience(2001) 8(1), 313425 There may be some academic debate as to whether subependymal nodules and SEGAs are two distinct lesions in respect of their growth potential,

11、 or are a continuum, in which small subependymal nodules without any growth potential are at one end and SEGAs without growth potential are at the other end. Several authors have claimed that the sube-pendymal nodules, which are located near the foramen of Monro, are not or are only partially calcif

12、ied and are enhanced after gadolinium, have a higher probability of evolving into a tumour, particularly in familial cases of TS.subependymalnodulesNabbout R, et al. Early diagnosis of subependymal giant cell astrocytoma in children with tuberous sclerosis. J Neurol Neurosurg Psychiartry 1999; 66: 3

13、70375.26多形黄色星形细胞瘤大体病理邻近脑膜的皮质囊性肿块伴壁结节镜下病理肿瘤很明显的位于皮质区。多形性的表现：纤维性和巨大多核新生的星形细胞；大黄色瘤细胞（含脂肪成分）；密实的网状结构；淋巴细胞浸润。缺少坏死，有丝分裂；可伴皮质发育不良分期与分级：WHO 级27CT表现平扫：囊性呈低密度伴混杂密度结节。实性呈低密度、高密度或混杂密度钙化、出血、颅骨侵蚀罕见增强：有时显著不均匀强化MRI表现T1WI：低或混杂信号; T2WI/FLAIR：高或混杂信号。 有些病例伴皮质发育不良增强：通常中度或显著强化，边界清，偶见脑膜尾征Pleomorphic xanthoastrocytoma: cli

14、nical, imaging and pathological features of four cases. Alfredo Bucciero et al.Clinical Neurology and Neurosurgery 99 (1997) 40-4528少枝少突神经胶质瘤一般病理情况：起源于皮质，向皮质下白质生长大体病理边界清晰，粉灰色，柔软的肿块。位于皮质，皮质下白质。钙化常见。出血、囊变可见。镜下病理中度增生的肿瘤细胞，偶尔伴有丝分裂。核圆、均质，胞质清晰。微小钙化可见，囊变或黏液样变。可有丰富的毛细血管网分期与分级：WHO 级间变型少枝胶质瘤：WHO 级Engelhard HH

15、, Stelea A, Cochran EJ. Oligodendroglioma: pathologyand molecular biology. Surg Neurol 2002;58:1117.2930CT表现平扫：低、等密度，大部分钙化，出血少见，20可见囊变增强：程度不同MRI表现信号不均：T1WI上低、等信号，T2WI上高信号，出血，坏死罕见局限性，有轻度的瘤周水肿50强化3132室管膜瘤大体病理边界清。柔软，分叶，灰粉色的肿块。可见囊变，坏死，出血。可越过第四脑室各孔，偶尔侵犯邻近室管膜的脑组织镜下病理肿瘤细胞围绕血管排列形成假菊形团，细胞成分中度。有丝分裂少，偶尔有核不典型变间

16、变型室管膜瘤：细胞成分增多。核不典型变，染色过深。微血管增生。肿瘤细胞呈假栅栏样排列伴多样的坏死分期与分级：WHO 级。WHO 级（间变型）3334CT表现平扫：大多数为等密度。可有出血，囊变，50伴钙化。常见脑积水增强：形式多样的不均匀强化MRI表现信号混杂：T1WI上略低信号，T2WI上等或低信号。常见钙化，出血，囊变，血管流空多达90伴脑积水增强：中度不均匀强化MRS：NAA/Cho，Cr/Cho较星形细胞瘤，髓母细胞瘤高3536They are common tumors in children, comprising about 10% of paediatric CNS, whil

17、e intraspinal ependymomas are more often in adults2/3 of the intracranial ependymomas are located in the infratentorial compartmentWhen in the fourth ventricle, they tend to conform to the ventricular cavity and extrude through the foramina of the fourth ventricle into the cisternsCalcifications are

18、 not infrequent,while haemorrhage is rareHolger Pettersson, et al. The encyclopaedia of medicle imaging(VI):neuroradiology and head and neck imaging.200037脉络丛肿瘤大体病理局限性，乳头状脑室内肿块。囊变出血常见。儿童好发于侧脑室三角区，成人好发于第四脑室、桥小脑角池镜下病理CPP：立方形上皮细胞伴纤维血管核心CPCa：细胞成分增多，核质比例升高。核形态多样，有丝分裂多见 分期与分级：CPP：WHO 级；CPCa: WHO 级3839CT表现

19、平扫：75等或低密度。脑积水。25出现点状钙化。偶尔有出血，囊性增强：显著均匀强化MRI表现T1WI上等低混杂信号增强：显著强化CPP可出现局限性侵犯室管膜旁脑组织，但范围扩大则提示CPCa。可见流空现象，出血DSA：脉络丛动脉增粗，血管染色浓密，延迟，动静脉分流常见4041Ji Hoon Shin et al. Choroid plexus papilloma in the posterior cranial fossaMR, CT, and angiographic findings.Journal of Clinical Imaging. 2001; 25: 154 162Chitra

20、Sarkar et al. Choroid Plexus Papilloma:A Clinicopathological Study of 23 CasesSurg Neurol 1999;52:379 Propensity to arise at the foramen of Luschka with extraventricular extension Occasional peritumoral signal voids/cysts or calcification Weaker enhancement on MR or CT Less strong tumor staining by

21、the anterior or posterior inferior cerebellar artery on angiography The lack of hydrocephalus of the extraventricular CPPs to overproduce CSF due to their having less blood supply than the intraventricular CPPs Tumoral calcification has been reported to be present in 24% of the CT cases of CPPsAdult

22、 choroid plexus papilloma in the posterior cranial fossa4243节细胞胶质瘤病因病理机制病理生理：从胶质错构瘤或软脑膜下颗粒细胞转变而来；从胚胎性神经母细胞瘤或PNET分化而来大体病理实性或囊性肿块伴壁结节。常扩展到脑皮质镜下病理神经元变形，偶尔出现双核。新生的胶质细胞通常为星型细胞，GFAP+，有丝分裂罕见分期与分级：WHO级或级间变型节细胞胶质瘤WHO 级恶性伴胶质母细胞瘤样胶质细胞罕见，WHO 级4445CT表现平扫：密度多样：60低密度，40低等混杂密度，3540有钙化。表浅的病灶可扩展到颅骨增强：约50强化，中度不均匀强化MRI

23、表现信号多样：T1WI 上与灰质信号相当或略低，T2WI上稍高信号；FLAIR上不被抑制50强化：中度不均匀强化50伴皮质发育不良MRS：Cho/Cr升高464715例神经节细胞胶质瘤实性与囊实性肿瘤 1 2例 ,实性部分呈长或等1长2信号 ,信号不均匀 ,边缘欠清或清。注药后肿瘤可有不规则增强或均匀增强。实性部分内可有囊腔 ,钙化或伴有出血。囊性肿瘤 3例 ,囊性部分呈等脑脊液信号颞叶的肿瘤伴有钙化及脑内囊性肿瘤应与神经节细胞胶质瘤相鉴别杨建华 ,高培毅 ,陆荣庆。中枢神经系统神经节细胞胶质瘤的影像诊断。中国医学影像技术 2 0 0 2年第 1 8卷第 3期223-48 They are c

24、ircumscribed tumors that tend to have a cystic component and frequently calcify On CT they have different densities, but more frequently are iso- or hyperdense, and very often enhance with contrast节细胞胶质瘤 GangliogliomaLagares A et al. Ganglioglioma of the brainstem: report of three cases and review o

25、f the literature. Surg Neurol 2001;56:31524.4950 Hypointense or isointense on T1-weighted imaging MRI Hyperintense on T2-weighted imaging, and has been shown to be even more hyperintense on proton density imaging The tumor tends to be solid or at least have solid components, and the solid elements w

26、ill usually, but not always, enhance with gadolinium Gangliogliomas demonstrate higher cerebral blood volume compared with other low-grade gliomas but the degree of vascular permeability in gangliogliomas is similar to other low-grade gliomas 节细胞胶质瘤 GangliogliomaZentner Jet al. Gangliogliomas clinic

27、al radiological, and histopathological findings in 51 patients. J Neurol Neurosurg Psychiatry 1994;57:1497502M. Law et al. Conventional MR imaging with simultaneous measurements of cerebral blood volume and vascular permeability in ganglioglioma. Magnetic Resonance Imaging 22 (2004) 59960651M. Law e

28、t al.52胚胎发育不良性神经上皮瘤起源于发育不良的原始神经外胚层细胞大体病理颞叶好发，脑回变厚镜下病理多结节结构。显著特征：特异性的胶质神经元成分。与皮质垂直的不同质细胞呈柱状排列。少枝突样细胞围绕血管排列。其他细胞可向星形细胞，神经元分化。微囊性变。邻近皮质发育不良分期与分级：WHO 级53CT表现平扫：楔性低密度灶。皮质或皮质下。30延伸到脑室。20有钙化增强：80不强化。20结节或斑片样强化MRI表现T1WI上低信号T2WI上高信号FLAIR低等混杂信号无瘤周水肿增强： 1/3表现为点状或环形强化5455Due to the slow growth, the cortical loc

29、ation(usually in the temporal lobe) and the frequent presence of cysts, skull remodeling with erosion of the inner and middle table is frequently found in associationAt CT or MR, enhancement is usually absentHolger Pettersson, et al. The encyclopaedia of medicle imaging(VI):neuroradiology and head a

30、nd neck imaging.200056中央性神经细胞瘤大体病理色灰，质脆，局限性的脑室内肿块。血供中等，可出血，钙化镜下病理类似少枝胶质瘤。不规则的圆形细胞向神经元分化可有不同的结构形式：血管周围假菊形团（类似室管膜瘤）。蜂窝表现（类似少枝胶质瘤）。大的纤维区（类似松果体瘤）良性，间变坏死罕见。偶尔出现少量的有丝分裂，微血管增生分期与分级：WHO 级5758CT表现平扫：通常实性和囊性低等密度。50有钙化。脑积水常见增强：中度不均匀强化MRI表现信号不均：T1WI上大多数与皮质信号相等，T2WI上高信号部分病例可见流空效应中度至显著强化5960Spiros Sgouros, F.R.C.

31、S,et al. CENTRAL NEUROCYTOMA:A CORRELATIVE CLINICOPATHOLOGIC AND RADIOLOGIC ANALYSIS.Surg Neurol 1998;49:197-204.von Deimling A, Janzer R, Kleihues P, Wiestler OD.Patterns of differentiation in central neurocytoma.Acta Neuropathol 1990;79:473-9 It affects mainly young patients in the secondand third

32、 decade of life and is believed to arisefrom the neuronal cells of the septum pellucidurnand the subependymal plate of the lateral ventricles An entirely benign nature for this tumor is questioned and it appears that there may be malignant variants.Surgery should aim for maximum possible excision, a

33、s the location of the tumor allows. The role of postoperative radiotherapy remains controversial and may be considered in cases of subtotal excision of tumors with anaplastic histologic features. Chemotherapy may be of benefit in cases recurring despite61脑膜瘤病因：起源于蛛网膜的帽状细胞。大体病理边界清晰，圆形或分叶状，广基底与硬脑膜相连骨质

34、增生硬化常见。非肿瘤性的硬膜增厚常见明显的脑组织侵犯罕见镜下病理亚型：上皮型，纤维型，过渡型其他：血管瘤型，微囊型，分泌型，脊索样型，不典型脑膜瘤，间变型脑膜瘤分期与分级：90WHO 级。 57WHO 级（不典型，透明细胞型，脊索样型）。13WHO 级（间变型，乳头型，杆状型）6263CT表现平扫：骨质增生硬化，骨皮质不规则，内生骨疣常见。7075低密度，2025伴钙化，23伴瘤内或瘤旁囊变增强：90以上显著强化MRI表现所有序列上的信号通常都与脑皮质信号相等5065伴水肿25不典型变（坏死，囊变，出血）90以上显著强化，常不均匀硬膜尾征：3580出现，增厚的硬脑膜随着远离肿瘤而逐渐变细64其

35、他表现DWI，ADC：多样MRS：Cho/Cr与增生潜能相关，在1.5ppm出现丙氨酸峰提示脑膜瘤DSA：肿瘤周边由软脑膜血管供血，中心由硬脑膜血管供血65666768Nauta 分型：1型：囊腔或坏死腔位于肿瘤深部或中央，2型：囊腔或坏死腔位于肿瘤边缘 (远颅内侧)，3型：囊腔位于肿瘤周围脑组织内，4型：囊腔位于肿瘤脑组织之间（扩大的蛛网膜下腔），5型:与上述2型相仿，唯囊壁为纤维组织和肿瘤细胞岛所组成（Worthington）。但Feliciani等认为属Nauta2型的亚型囊性脑膜瘤69蛛 网 膜 下 腔脑 组 织囊 性 区脑 膜 瘤NAUTA 4 型：囊性区位于肿瘤和脑组织之间，为扩的

36、蛛网膜下腔NAUTA 2 型：囊性区位于肿瘤边沿NAUTA 1 型：囊性区位于肿瘤中央NAUTA 3 型：囊性区位于肿瘤邻近脑组织内7071恶性脑膜瘤大体病理肿瘤较大，呈膨胀性或浸润性生长，切面上多见出血、坏死、囊变镜下病理有明显的恶性肿瘤细胞表现；可见部分瘤组织保持典型的脑膜瘤结构外，有恶性表现例如指状浸润或弥漫浸润脑组织；瘤细胞丰富，细胞生长活跃，核异型明显，核大深染，可出现巨核细胞，核分裂相多见；常见坏死灶分期与分级：WHO归为级7273CT表现具有脑膜瘤的一般特征肿瘤边缘不规则或呈锯齿状，边界不清肿瘤平扫或增强扫描显示密度不均，斑片状强化囊变，出血可见肿瘤周围出现明显水肿而本身无或仅轻

37、微钙化肿瘤附近明显的骨质破坏并可向颅外蔓延肿瘤侵犯半球呈蘑伞状，又称蘑菇征74MRI表现肿瘤信号不均匀较良性脑膜瘤多见增强后扫描病灶呈斑片状或环状强化肿瘤形态多不规则，轮廓呈分叶状、结节状或锯齿状肿瘤包膜不完整，厚薄不一，不完整处镜下可见肿瘤组织侵犯并穿破包膜向脑内浸润粗短不规则形硬膜尾征向颅内外浸润生长颅外远处转移术后易复发MRS分析，恶性脑膜瘤表现为NAA成分无或少，Cho/Cr比例升高，可见脂肪酸族代谢75脑浸润可发生于组织学上为良性、非典型性或间变性（恶性）脑膜瘤，有脑浸润的脑膜瘤较易复发，伴有组织学上脑浸润的良性脑膜瘤的临床过程与非典型性脑膜瘤相似，但不出现非典型性和间变性（恶性）脑

38、膜瘤的遗传学（基因）改变。言外之义，脑浸润=非典型性脑膜瘤陈星荣。 脑膜瘤。中国医学计算机成像杂志。200276脑浸润的确定性征象：肿瘤边缘毛糙模糊，蘑菇征，伪足征（肿瘤边缘指状突出），毛刷征，为脑浸润的确定性征象。脑浸润的提示性征象:肿瘤轮廓呈节结状或分叶状。陈星荣。 脑膜瘤。中国医学计算机成像杂志。200277蘑菇征为脑浸润的确定性征象78蛛网膜浸润:扩大蛛网膜下腔内毛刺状增强79血管外皮细胞瘤大体病理许多血管外皮细胞瘤类似脑膜瘤。34为边界清楚、质硬、有包膜的分叶状肿决。可有宽或窄基底与硬脑膜联系。血管外皮细胞瘤为含有许多穿支血管的富血供肿瘤镜下病理可见丰富的细胞和血管形成致密的弥漫的网

39、络结构，呈小叶状排列的肿瘤细胞周围绕以鹿角血管为其特征。可见有丝分裂分期与分级：WHO将血管外皮细胞瘤归为起源不明肿瘤类8081CT表现平扫：多呈低等混合密度。其内常见囊变或坏死。骨窗显示病灶局部侵蚀性骨质破坏增强：病灶呈不均匀强化MRI表现T1WI呈等信号， PDWI、 T2WI呈略高信号信号不均匀，与肿瘤坏死、囊变及肿瘤血管流空有关增强后扫描明显不均匀强化8283血管母细胞瘤大体病理局限性边界清晰，可见血管丰富的结节，囊变镜下病理通常囊壁压迫脑组织而不是肿瘤实质。结节成分为大的空泡样的基质细胞和丰富的毛细血管网分期与分级：WHO 级84CT表现平扫：低密度囊等密度结节增强：常见：结节显著均

40、匀强化，囊不强化 少见：实性肿块 罕见：环状强化的肿块MRI表现T1WI：囊肿低信号，结节等信号T2WI：高信号部分病例出现明显的流空效应;结节显著强化DSA：大的乏血管肿块（囊肿）血管丰富的结节（有时见动静脉分流）858687髓母细胞瘤大体病理质硬，边界清或质软，边界不清镜下病理细胞密集，核圆或椭圆，胞质稀少。分化不好的神经外胚层细胞瘤细胞围绕一神经纤维作放射状排列形成典型的菊型团有丝分裂和细胞凋亡常见四种亚型：促纤维增生型，MB伴广泛结节，大细胞型，黑色素型分期与分级：WHO 级。88促纤维增生型MB89CT表现平扫：后颅凹中线的低密度实性肿块。1020伴钙化。第四脑室向前移位增强：90以

41、上强化。强化程度由轻度到中度,强化形式由斑片状到均匀一致的强化MRI表现第四脑室中线处信号均匀的肿块T1WI上等/低信号，T2WI等信号或低高混杂信号可见囊变，出血，坏死90出现程度不同的强化50可见脑脊液播散MRS ：NAA/Cho降低，Cr/Cho降低909192Frost et al. medulloblastomas have a lateral location in 30% of cases inadults and 7% in children.Sarkar et al. lateral location was more common in adults (46.4%) as

42、compared to childhood cases(10.7%)Frost JP, et al. Medulloblastoma in adults. Int J Radiat Oncol Biol Phys 1995;32:9517.Sarkar C, et al. Are childhood and adult medulloblastoma different? A comparative study of clinicopathological features, proliferation index and apoptotic index. J Neuroncol 2002;5

43、9:4961.93The classic well-defined homogeneous vermian tumour with intense contrast enhancement seems to be rare in adults, whose tumours are predominantly in the cerebellar hemisphere, poorly defined and enhance lessMalheiros SM, Carrete Jr H, Stavale JN, et al. MRI of medulloblastoma in adults. Neu

44、roradiology 2003;45:4637.94CPA medulloblastomas are rare and only 19 cases have been reported thus far. Most of the reported cases were adults, ranging between 19 and 46 yearsTherefore, from the viewpoint of a differential diagnosis, the most important factor is to bear in mind the possibility of a

45、CPA medulloblastomaAwadhesh K, et al.Cerebellopointine angle medulloblastoma. Journal of Clinical Neuroscience (2004) 11(1), 424595原发脑淋巴瘤98是B细胞淋巴瘤，T细胞罕见；90在幕上，局限性多于浸润性。2025为多发病变大体病理大脑半球的单发或多发病变。中心有坏死，HIV阳性病人伴出血镜下病理以血管为中心，环绕、浸润血管及血管周围间隙。有几种亚型，其中大细胞型占近50，核浆质比例升高96CT表现平扫：低密度，偶尔等密度。可出血，坏死增强：常见中度均匀强化；少见环

46、状强化 罕见：不强化（浸润性，与白质脑病相仿）MRI表现T1WI及T2WI均为与皮质等或低信号FLAIR上为高信号显著均匀强化DWI：弥散受限MRS：NAA降低，Cho升高，可出现脂峰或乳酸峰9798Deep location explains that seizures are less frequent than in other brain tumoursCT scans and MRI typically show in a third of cases unique or multiple periventricular, homogeneously enhancing lesion

47、s Ring-like enhancement is rare in immunocompetent patients, but atypical features can simulate inflammatory or infectious diseases or other brain tumours (meningiomas) Spontaneous (or steroid-induced) disappearance of lesions is classic, hence the term ghost tumoursAnthony Behin,et al. Primary brai

48、n tumours in adultsTHE LANCET Vol 361 January 25, 200399CT usually reveals single or multiple isodense or hypodense lesions with intense contrast enhancement in more than 90% of the cases, indicating either unifocal or multifocal disease with perifocal edema which is less prominent than edema in mal

49、ignant glioma or metastases Neuroradiological gold standard of both diagnosis as well as monitoring therapy is MRI, which shows hypointense, frequently multiple enhancing lesions in T1weighted images and hyperintense tumor and edema in T2-weighted images with about 20% of the lesions revealing conta

50、ct with the ependyma of the ventricular wall Lanfermann H, et al. CT and MR imaging in primary cerebral non-Hodgkins lymphoma. Acta Radiol 1997;38:25967100Radiological hallmark of PCNSL is a periventricular growth pattern; however, lesions may be cortical, well circumscribed and indistinguish-able f

51、rom other brain tumorsPrimarily non-enhancing lesions, suggestive of leukoencephalopathy or other differential diagnosis may rarely be present U . Schlegel et al . Primary CNS lymphoma: clinical presentation, pathological classification,molecular pathogenesis and treatment. Journal of the Neurologic

52、al Sciences 181 (2000) 1 12101生殖细胞瘤无胞膜的实质性肿块，可有微囊变。坏死出血不常见，除非肿瘤在基底节区发病部位：8090在中线（松果体区鞍上两者均发）。510在基底节、丘脑大体病理质软，脆，灰褐色肿块镜下病理细胞均匀呈层状或分叶状核大，胞质透明，富含糖原沿纤维血管常有淋巴细胞浸润102CT表现平扫：第三脑室后方等或高密度肿块。围绕结节状聚集的钙化（被包裹的松果体）脑积水增强：显著均匀一致强化。寻找其他的病变（鞍上，室管膜）MRI表现T1WI通常等或稍低信号，T2WI高信号有囊变者，信号不均近50病例为多发103104 Infundibular thickeni

53、ng ( 16 mm) was observed in all 13 Hyperintensity of the posterior pituitary on T1-weighted image was absent in all 13 cases (100%) Ten germinomas (77%) were isointense to cerebral cortex on T1-weighted image, but variable intensities were exhibited on T2-weighted image MR images revealed intratumor

54、al cysts in six cases (46%) Intra-third ventricular extension Eleven of the 13 cases (85%) revealed hyperdense solid components on unenhanced CT. Calcification was absent in all cases (100%)Mitsunori Kanagaki, et al.MRI and CT findings of neurohypophyseal germinoma. European Journal of Radiology. 20

55、04 ;49 : 204211MRI and CT findings of neurohypophyseal germinoma105Infundibular thickening, absence of the posterior pituitary high signal on T1-weighted image, lack of calcification and hyperdensity on unenhanced CT are common imaging features of neurohypophyseal germinomaMitsunori Kanagaki, et al.

56、MRI and CT findings of neurohypophyseal germinoma. European Journal of Radiology. 2004 ;49 : 204211106松果体瘤大体病理：松果体母细胞瘤：质软，易碎，边界模糊，浸润邻近组织松果体细胞瘤：边界清晰，灰色，可压迫邻近组织，但无侵袭性镜下病理：松果体母细胞瘤：细胞排列密集，体积小，未分化。核染色体浓密，呈圆形，胡萝卜形，胞质稀少。偶尔见菊形团。大部分坏死。有丝分裂常见。松果体细胞瘤：肿瘤呈分叶状，被间充质细胞分隔。细胞成熟，大小均匀，与松果体细胞相似107分期与分级：WHO：松果体母细胞瘤 级， 松果

57、体细胞瘤 级新分级方法：1级：松果体细胞瘤2级：有丝分裂数目6或95为CS F样的低密度。1025含钙化增强：多无强化，极少有边缘强化MRI特点 在所有的常规序列上等于/稍高于CSF信号DWI上弥散降低（高信号）147148皮样囊肿大体病理单腔囊肿的厚壁由结缔组织构成。囊内混合着含油脂的脂肪，胆固醇碎屑。常含有头发镜下病理纤维结缔组织构成外层壁。内衬有角质化的鳞状上皮，皮肤附属器（皮脂腺、汗腺、发囊）。脱屑的角质蛋白，细胞残骸。含有牙釉质的牙齿149150CT表现平扫：圆形或结节状囊性肿块。含脂肪密度（极少为实质性）。20有钙化破裂时脂肪散布于脑池，在脑室内见到脂肪液体平面。颅骨囊肿引起板障扩

58、大增强：一般无强化 MRI表现T1WI：囊性肿块，破裂后的脂肪呈高信号抑脂序列可确诊在囊内有脂肪液体平面，脑室内亦常见 T2 WI：呈多样性。频率编码方向有化学位移伪影。特殊序列用于检出微小的脂滴151152Rathke囊肿大体病理位于鞍上或鞍内边缘光滑的分叶状囊性肿块，囊内是清亮白色的类黏蛋白镜下病理囊壁是单层纤毛立方或柱状上皮，有或无杯状细胞。囊液为清亮的或浆液性的液体。有时含出血或含铁血黄素、无定形的浓缩嗜酸性伊红染色阳性胶样物或坚硬的似腊样浓缩物质153154CT表现平扫：边界清晰的圆形或分叶状鞍内或鞍上肿块；40位于鞍内，60向鞍上延伸 50为低密度，25混合密度，1015囊壁上弯曲

59、线条样钙化增强：无强化MRI表现位于鞍内和/或鞍上信号：3040如CSF（T1 WI低、T2 WI高信号）； 5060呈T1 WI高、T2 WI等/低信号；510混合信号155156松果体囊肿大体病理光滑柔软的棕褐色到黄色的囊壁；囊内常见黄色清亮或出血性液体；80小于10mm，可增大镜下病理外层为纤细（常为不完全）的纤维层；中层为松果体实质，伴或不伴有钙化；内层的胶质组织含有变异的吞噬有颗粒小体、含铁血黄素的巨噬细胞157CT特点平扫：第三脑室背侧边界清晰、光滑的囊肿。囊肿液体与CSF密度相等或略高。25囊壁钙化增强：边缘或结节状强化MRI特点 信号多样性：40在T1WI、T2WI上与CSF相

60、同，25在PDI上略高于CSF信号可见出血和占位效应60可边缘部分强化或结节完全强化在延迟时可如实质性肿块完全强化158脊索瘤大体病理肿块呈灰褐色。分界清楚并有假包膜；大多呈分叶状柔软胶冻状，少数硬如软骨。50肿瘤内可见散在结节状或斑片状钙化。可见新老出血区和囊变/坏死灶。有些肿瘤表现局灶性骨组织点缀在肿瘤基质内。多伴广泛斜坡/颅底骨质破坏。复发的病灶一般呈多发结节状镜下病理肿瘤细胞分化较好时，由呈囊状或团状囊泡样细胞组成。典型肿瘤细胞呈梭形或多边形；细胞质内具有明显的空泡；细胞体积较大且排列稀疏；细胞间质内可有纤维间隔和丰富的黏液聚积159160CT表现平扫：为以斜坡和岩裂尖为中心的略高密度