腦腫瘤的病理和影像學特征

1、腦腫瘤的病理和影像學特征,華山醫(yī)院放射科 姚振威,腦外腫瘤的MR征象,提示征象周邊、廣基緊貼顱骨鄰近顱骨改變鄰近腦膜強化鄰近腦組織受推移遠離顱骨,肯定征象腦組織和病灶間存在腦脊液間隙腦組織和病灶間可見血管間隔腫塊和白質（水腫）間可見皮層結構 硬（腦）膜外腫塊與腦組織間可見硬膜結構,低級星形細胞瘤,大體病理受侵腦組織腫脹，扭曲變形；浸潤腫塊灰白質面模糊；大體上可以為局限性的，也可彌漫地浸潤鄰近腦組織；偶爾呈囊性，可

2、見鈣化鏡下病理新生的分化較好的纖維型星形細胞和肥胖型星形細胞；組織結構疏松，常有微囊變的腫瘤基質；中度增生的腫瘤細胞實質；偶爾出現(xiàn)核不典型變；缺乏有絲分裂或罕有；沒有微血管的增生及壞死組織分型：纖維型、肥胖型、原漿型分期及分級標準：WHOⅡ級,CT表現(xiàn)平掃：境界不清的均勻的低/等密度腫塊；20%有鈣化；囊變罕見增強：無強化（若有強化則提示局部惡性變)MRI表現(xiàn)信號強度：T1WI低信號，T2WI及FLAIR高信號。

3、鈣化、囊變少見。出血、瘤周水腫罕見。可擴散到鄰近腦組織可表現(xiàn)為局限性的，但可浸潤鄰近腦組織。通常無強化；強化則提示向高度惡性進展 。DWI：通常缺乏限制性彌散 MRS：高Cho，低NAA，高MI/Cr(0.85±0.25）,間變型星形細胞瘤,大體病理浸潤性腫塊，邊界不清。結構可以比較稀疏但侵襲鄰近組織。囊變，出血不常見鏡下病理結構更密實。顯著的有絲分裂，核不典型變核漿比升高, 壞死及微血管增生?？沙?/p>

4、現(xiàn)肥胖細胞的變異WHO Ⅲ級,CT表現(xiàn)平掃：低密度腫塊；鈣化罕見增強：大多數(shù)不強化MRI表現(xiàn)信號強度：T1WI為混雜等、低信號，T2WI、FLAIR為混雜的高信號。鈣化、出血、囊變罕見。增強掃描：通常無強化，可有局灶性、結節(jié)狀、均一、斑片狀強化。任何強化都應提示膠質母細胞瘤的可能。MRS：Cho/Cr升高，NAA降低,多形性膠質母細胞瘤,大體病理絕大多數(shù)多形性膠質母細胞瘤血供豐富。大體上可見出血；壞死核心周圍環(huán)繞

5、著灰紅色的腫瘤組織鏡下病理壞死，微血管增生星形細胞形態(tài)多樣顯著的核不典型變大量的有絲分裂分期與分級：WHO Ⅳ級,CT表現(xiàn)平掃：周圍等密度，中心低密度，出血±，鈣化罕見。增強：顯著，不均勻，不規(guī)則強化MRI表現(xiàn)信號強度（通常為混雜性）：T1WI：等、低信號（可能有亞急性出血）；T2WI/FLAIR：高信號伴瘤周水腫，腫瘤的邊界超過異常信號之外動態(tài)對比增強MRI能反映微血管的通透性，有助于腫瘤的分級診斷

6、,DSA：血供豐富，顯著的腫瘤染色，動靜脈分流MRS：NAA、MI降低，Cho/Cr、乳酸/水升高DWI：比低度惡性的星型細胞瘤的ADC測量值低PWI：可鑒別GBM與低度惡性星型細胞瘤（GBM的rCBV高）,大腦膠質瘤病,大體病理分兩種類型：1、腫瘤在腦組織上過度生長或擴展，但沒有明確的腫塊；2、彌漫性病灶＋局限性腫塊鏡下病理膠質細胞拉長，核深染，有絲分裂變異；膠質細胞通常平行排列；沿有髓鞘的神經纖維彌漫性浸潤；微血管增生，

7、缺乏壞死；GFAP＋；細胞成分為主型的偶爾是少突膠質細胞瘤分期與分級：通常WHO Ⅲ級,CT表現(xiàn) 平掃：邊界不清，非對稱，低密度增強：通常不強化MRI表現(xiàn)T1WI：等/低信號T2WI/FLAIR：高信號輕度強化，局灶性強化可代表惡性膠質瘤MRS：Cho/Cr、Cho/NAA升高，乳酸±，出現(xiàn)脂質峰,大體病理境界清楚，質軟、囊性、灰色腫塊。無包膜，質地較硬，常伴囊變，有時囊變部分可大大超過瘤體本身，而將瘤體推向

8、一側形成壁結節(jié)鏡下病理腫瘤細胞多細長，自細胞一端或兩端發(fā)出毛發(fā)絲狀纖維突起和嗜酸小體分期與分級：WHO Ⅰ級,毛細胞型星形細胞瘤,CT表現(xiàn)平掃：小腦蚓部或小腦半球稀疏的囊/實性腫塊；無瘤周水腫；低/等密度；20％有鈣化增強：>95％強化（強化形式各異）MRI表現(xiàn)實性或結節(jié)在T1WI上低/等信號，T2WI上高信號。囊性成分在T2WI上高信號，F(xiàn)LAIR上不被抑制。不均勻強化。MRS：高Cho，低NAA，高

9、乳酸,ADULT PATIENTS WITH SUPRATENTORIAL PILOCYTIC ASTROCYTOMAS:A PROSPECTIVE MULTICENTER CLINICAL TRIAL. PAUL D. BROWN et al.Int. J. Radiation Oncology Biol. Phys., Vol. 58, No. 4, 1153–1160, 2004,PAUL D. BROWN et al. AD

10、ULT 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 in

11、volved site Malignant transformation 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 t

12、herapy need not be offered to adults with supra- tentorial pilocytic astrocytomas who have undergone gross or subtotal resection,室管膜下巨細胞型星形細胞瘤,多為結節(jié)性硬化伴發(fā)錯構瘤惡變大體病理邊界清楚的分葉狀腫塊。常見鈣化、囊變、豐富的血管鏡下病理典型者呈雙核或多核星形細胞，常見囊變、壞死

13、，可見大的腫脹星形細胞胞質呈玻璃樣嗜酸性，分化良好，有絲分裂罕見分期與分級：WHO將其歸為Ⅰ級,CT表現(xiàn)平掃：常見一側側腦室或二側側腦室擴大, 腫瘤多呈低等混合密度，可見鈣化和囊變也可見沿紋狀體丘腦溝的室管膜下錯構結節(jié)，該結節(jié)呈等密度，伴鈣化或不伴鈣化增強：可見明顯不均勻強化動態(tài)掃描顯示達峰值時間縮短，密度下降期延長MRI表現(xiàn)平掃T1WI為低等混合信號，T2WI為等或高信號增強后常有明顯不均勻強化,Shunji Ni

14、shio et al. Subependymal giant cell astrocytoma: clinicaland neuroimaging features of four cases. Journal of Clinical Neuroscience(2001) 8(1), 31–34,There may be some academic debate as to whether subependymal nodules an

15、d SEGAs are two distinct lesions in respect of their growth potential, 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 oth

16、er end. Several authors have claimed that the ‘sube-pendymal nodules’, which are located near the foramen of Monro, are not or are only partially calcified and are enhanced after gadolinium, have a higher probability

17、 of evolving into a tumour, particularly in familial cases of TS.,subependymalnodules,Nabbout R, et al. Early diagnosis of subependymal giant cell astrocytoma in children with tuberous sclerosis. J Neurol Neurosurg Psych

18、iartry 1999; 66: 370–375.,多形黃色星形細胞瘤,大體病理鄰近腦膜的皮質囊性腫塊伴壁結節(jié)鏡下病理腫瘤很明顯的位于皮質區(qū)。多形性的表現(xiàn)：纖維性和巨大多核新生的星形細胞；大黃色瘤細胞（含脂肪成分）；密實的網狀結構；淋巴細胞浸潤。缺少壞死，有絲分裂；可伴皮質發(fā)育不良分期與分級：WHO Ⅱ級,CT表現(xiàn)平掃：囊性呈低密度伴混雜密度結節(jié)。實性呈低密度、高密度或混雜密度鈣化、出血、顱骨侵蝕罕見增強：有時顯著不均勻

19、強化MRI表現(xiàn)T1WI：低或混雜信號; T2WI/FLAIR：高或混雜信號。 有些病例伴皮質發(fā)育不良增強：通常中度或顯著強化，邊界清，偶見腦膜尾征,Pleomorphic xanthoastrocytoma: clinical, imaging and pathological features of four cases. Alfredo Bucciero et al.Clinical Neurology and Neuros

20、urgery 99 (1997) 40-45,少枝少突神經膠質瘤,一般病理情況：起源于皮質，向皮質下白質生長大體病理邊界清晰，粉灰色，柔軟的腫塊。位于皮質，皮質下白質。鈣化常見。出血、囊變可見。鏡下病理中度增生的腫瘤細胞，偶爾伴有絲分裂。核圓、均質，胞質清晰。微小鈣化可見，囊變或黏液樣變?？捎胸S富的毛細血管網分期與分級：WHO Ⅱ級間變型少枝膠質瘤：WHO Ⅲ級,Engelhard HH, Stelea A, Cochran

21、 EJ. Oligodendroglioma: pathologyand molecular biology. Surg Neurol 2002;58:111–7.,CT表現(xiàn)平掃：低、等密度，大部分鈣化，出血少見，20％可見囊變增強：程度不同MRI表現(xiàn)信號不均：T1WI上低、等信號，T2WI上高信號，出血，壞死罕見局限性，有輕度的瘤周水腫50％強化,室管膜瘤,大體病理邊界清。柔軟，分葉，灰粉色的腫塊。可見囊變，壞死，

22、出血?？稍竭^第四腦室各孔，偶爾侵犯鄰近室管膜的腦組織鏡下病理腫瘤細胞圍繞血管排列形成假菊形團，細胞成分中度。有絲分裂少，偶爾有核不典型變間變型室管膜瘤：細胞成分增多。核不典型變，染色過深。微血管增生。腫瘤細胞呈假柵欄樣排列伴多樣的壞死分期與分級：WHO Ⅱ級。WHO Ⅲ級（間變型）,CT表現(xiàn)平掃：大多數(shù)為等密度?？捎谐鲅?，囊變，50％伴鈣化。常見腦積水增強：形式多樣的不均勻強化MRI表現(xiàn)信號混雜：T1WI上略低信號，T

23、2WI上等或低信號。常見鈣化，出血，囊變，血管流空多達90％伴腦積水增強：中度不均勻強化MRS：NAA/Cho，Cr/Cho較星形細胞瘤，髓母細胞瘤高,They are common tumors in children, comprising about 10% of paediatric CNS, while intraspinal ependymomas are more often in adults2/3 of the

24、 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 ciste

25、rnsCalcifications are not infrequent,while haemorrhage is rare,Holger Pettersson, et al. The encyclopaedia of medicle imaging(VI):neuroradiology and head and neck imaging.2000,脈絡叢腫瘤,大體病理局限性，乳頭狀腦室內腫塊。囊變出血常見。兒童好發(fā)于側腦室三角區(qū)，

26、成人好發(fā)于第四腦室、橋小腦角池鏡下病理CPP：立方形上皮細胞伴纖維血管核心CPCa：細胞成分增多，核質比例升高。核形態(tài)多樣，有絲分裂多見 分期與分級：CPP：WHO Ⅰ級；CPCa: WHO Ⅲ級,CT表現(xiàn)平掃：75％等或低密度。腦積水。25％出現(xiàn)點狀鈣化。偶爾有出血，囊性增強：顯著均勻強化MRI表現(xiàn)T1WI上等低混雜信號增強：顯著強化CPP可出現(xiàn)局限性侵犯室管膜旁腦組織，但

27、范圍擴大則提示CPCa?？梢娏骺宅F(xiàn)象，出血DSA：脈絡叢動脈增粗，血管染色濃密，延遲，動靜脈分流常見,Ji Hoon Shin et al. Choroid plexus papilloma in the posterior cranial fossaMR, CT, and angiographic findings.Journal of Clinical Imaging. 2001; 25: 154– 162Chitra

28、Sarkar et al. Choroid Plexus Papilloma:A Clinicopathological Study of 23 CasesSurg Neurol 1999;52:37–9,Propensity to arise at the foramen of Luschka with extraventricular extension Occasional peritumoral signal v

29、oids/cysts or calcification Weaker enhancement on MR or CT Less strong tumor staining by the anterior or posterior inferior cerebellar artery on angiography The lack of hydrocephalus of the extraventricular CP

30、Ps 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 CPPs,Adult choroid plexus papill

31、oma in the posterior cranial fossa,節(jié)細胞膠質瘤,病因－病理機制－病理生理：從膠質錯構瘤或軟腦膜下顆粒細胞轉變而來；從胚胎性神經母細胞瘤或PNET分化而來大體病理實性或囊性腫塊伴壁結節(jié)。常擴展到腦皮質鏡下病理神經元變形，偶爾出現(xiàn)雙核。新生的膠質細胞通常為星型細胞，GFAP+，有絲分裂罕見分期與分級：WHOⅠ級或Ⅱ級間變型節(jié)細胞膠質瘤WHO Ⅲ級惡性伴膠質母細胞瘤樣膠質細胞罕見，WHO Ⅳ

32、級,CT表現(xiàn)平掃：密度多樣：60％低密度，40％低等混雜密度，35％~40％有鈣化。表淺的病灶可擴展到顱骨增強：約50％強化，中度不均勻強化MRI表現(xiàn)信號多樣：T1WI 上與灰質信號相當或略低，T2WI上稍高信號；FLAIR上不被抑制50％強化：中度不均勻強化50％伴皮質發(fā)育不良MRS：Cho/Cr升高,15例神經節(jié)細胞膠質瘤實性與囊實性腫瘤 1 2例 ,實性部分呈長或等Ｔ1長Ｔ2信號 ,信號不均勻 ,邊緣欠清或清。注

33、藥后腫瘤可有不規(guī)則增強或均勻增強。實性部分內可有囊腔 ,鈣化或伴有出血。囊性腫瘤 3例 ,囊性部分呈等腦脊液信號顳葉的腫瘤伴有鈣化及腦內囊性腫瘤應與神經節(jié)細胞膠質瘤相鑒別,楊建華 ,高培毅 ,陸榮慶。中樞神經系統(tǒng)神經節(jié)細胞膠質瘤的影像診斷。中國醫(yī)學影像技術　 2 0 0 2年　第 1 8卷　第 3期223-,They are circumscribed tumors that tend to have a cystic

34、 component and frequently calcify On CT they have different densities, but more frequently are iso- or hyperdense, and very often enhance with contrast,節(jié)細胞膠質瘤 Ganglioglioma,Lagares A et al. Ganglioglioma

35、of the brainstem: report of three cases and review of the literature. Surg Neurol 2001;56:315–24.,Hypointense or isointense on T1-weighted imaging MRI Hyperintense on T2-weighted imaging, and has been shown to be e

36、ven more hyperintense on proton density imaging The tumor tends to be solid or at least have solid components, and the solid elements will usually, but not always, enhance with gadolinium Gangliogliomas demon

37、strate 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,節(jié)細胞膠質瘤 Ganglioglioma,Zentner Jet al. G

38、angliogliomas clinical radiological, and histopathological findings in 51 patients. J Neurol Neurosurg Psychiatry 1994;57:1497–502M. Law et al. Conventional MR imaging with simultaneous measurements of cerebral blood vo

39、lume and vascular permeability in ganglioglioma. Magnetic Resonance Imaging 22 (2004) 599–606,M. Law et al.,胚胎發(fā)育不良性神經上皮瘤,起源于發(fā)育不良的原始神經外胚層細胞大體病理顳葉好發(fā)，腦回變厚鏡下病理多結節(jié)結構。顯著特征：特異性的膠質神經元成分。與皮質垂直的不同質細胞呈柱狀排列。少枝突樣細胞圍繞血管排列。其他細胞可向星形

40、細胞，神經元分化。微囊性變。鄰近皮質發(fā)育不良分期與分級：WHO Ⅰ級,CT表現(xiàn)平掃：楔性低密度灶。皮質或皮質下。30％延伸到腦室。20％有鈣化增強：80％不強化。20％結節(jié)或斑片樣強化MRI表現(xiàn)T1WI上低信號T2WI上高信號FLAIR低等混雜信號無瘤周水腫增強： 1/3表現(xiàn)為點狀或環(huán)形強化,Due to the slow growth, the cortical location(usually in the t

41、emporal 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 absent,Holger Pettersson, et al. The en

42、cyclopaedia of medicle imaging(VI):neuroradiology and head and neck imaging.2000,中央性神經細胞瘤,大體病理色灰，質脆，局限性的腦室內腫塊。血供中等，可出血，鈣化鏡下病理類似少枝膠質瘤。不規(guī)則的圓形細胞向神經元分化可有不同的結構形式：血管周圍假菊形團（類似室管膜瘤）。蜂窩表現(xiàn)（類似少枝膠質瘤）。大的纖維區(qū)（類似松果體瘤）良性，間變壞死罕見。偶爾出現(xiàn)

43、少量的有絲分裂，微血管增生分期與分級：WHO Ⅱ級,CT表現(xiàn)平掃：通常實性和囊性低等密度。50％有鈣化。腦積水常見增強：中度不均勻強化MRI表現(xiàn)信號不均：T1WI上大多數(shù)與皮質信號相等，T2WI上高信號部分病例可見流空效應中度至顯著強化,Spiros Sgouros, F.R.C.S,et al. CENTRAL NEUROCYTOMA:A CORRELATIVE CLINICOPATHOLOGIC AND RADIO

44、LOGIC 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 se

45、condand third 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

46、 it appears that there may be malignant variants.Surgery should aim for maximum possible excision, as the location of the tumor allows. The role of postoperative radiotherapy remains controversial and may be considered i

47、n cases of subtotal excision of tumors with anaplastic histologic features. Chemotherapy may be of benefit in cases recurring despite,腦膜瘤,病因：起源于蛛網膜的帽狀細胞。大體病理邊界清晰，圓形或分葉狀，廣基底與硬腦膜相連骨質增生硬化常見。非腫瘤性的硬膜增厚常見明顯的腦組織侵犯罕見鏡下病理亞型：

48、上皮型，纖維型，過渡型其他：血管瘤型，微囊型，分泌型，脊索樣型，不典型腦膜瘤，間變型腦膜瘤分期與分級：90％WHO Ⅰ級。 5％~7％WHO Ⅱ級（不典型，透明細胞型，脊索樣型）。1％~3％WHO Ⅲ級（間變型，乳頭型，桿狀型）,CT表現(xiàn)平掃：骨質增生硬化，骨皮質不規(guī)則，內生骨疣常見。70％~75％低密度，20％~25％伴鈣化，2％~3％伴瘤內或瘤旁囊變增強：90％以上顯著強化MRI表現(xiàn)所有序列上的信號通常都與腦皮質信號

49、相等50％~65％伴水腫25％不典型變（壞死，囊變，出血）90％以上顯著強化，常不均勻硬膜尾征：35％~80％出現(xiàn)，增厚的硬腦膜隨著遠離腫瘤而逐漸變細,其他表現(xiàn)DWI，ADC：多樣MRS：Cho/Cr與增生潛能相關，在1.5ppm出現(xiàn)丙氨酸峰提示腦膜瘤DSA：腫瘤周邊由軟腦膜血管供血，中心由硬腦膜血管供血,Nauta 分型：1型：囊腔或壞死腔位于腫瘤深部或中央，2型：囊腔或壞死腔位于腫瘤邊緣 (遠顱內側)，3型：囊腔

50、位于腫瘤周圍腦組織內，4型：囊腔位于腫瘤腦組織之間（擴大的蛛網膜下腔），5型:與上述2型相仿，唯囊壁為纖維組織和腫瘤細胞島所組成（Worthington）。但Feliciani等認為屬Nauta2型的亞型,囊性腦膜瘤,蛛 網 膜 下 腔,腦 組 織,囊 性 區(qū),腦 膜 瘤,NAUTA 4 型：囊性區(qū)位于腫瘤和腦組織之間，為擴的蛛網膜下腔,NAUTA 2 型：囊性區(qū)位于腫瘤邊沿,NAUTA 1 型：囊性區(qū)位于腫瘤中央,NAUTA

51、 3 型：囊性區(qū)位于腫瘤鄰近腦組織內,惡性腦膜瘤,大體病理腫瘤較大，呈膨脹性或浸潤性生長，切面上多見出血、壞死、囊變鏡下病理有明顯的惡性腫瘤細胞表現(xiàn)；可見部分瘤組織保持典型的腦膜瘤結構外，有惡性表現(xiàn)例如指狀浸潤或彌漫浸潤腦組織；瘤細胞豐富，細胞生長活躍，核異型明顯，核大深染，可出現(xiàn)巨核細胞，核分裂相多見；常見壞死灶分期與分級：WHO歸為Ⅲ~Ⅳ級,CT表現(xiàn)具有腦膜瘤的一般特征腫瘤邊緣不規(guī)則或呈鋸齒狀，邊界不清腫瘤平掃或

52、增強掃描顯示密度不均，斑片狀強化囊變，出血可見腫瘤周圍出現(xiàn)明顯水腫而本身無或僅輕微鈣化腫瘤附近明顯的骨質破壞并可向顱外蔓延腫瘤侵犯半球呈蘑傘狀，又稱蘑菇征,MRI表現(xiàn)腫瘤信號不均勻較良性腦膜瘤多見增強后掃描病灶呈斑片狀或環(huán)狀強化腫瘤形態(tài)多不規(guī)則，輪廓呈分葉狀、結節(jié)狀或鋸齒狀腫瘤包膜不完整，厚薄不一，不完整處鏡下可見腫瘤組織侵犯并穿破包膜向腦內浸潤粗短不規(guī)則形硬膜尾征向顱內外浸潤生長顱外遠處轉移術后易復發(fā)MRS分析

53、，惡性腦膜瘤表現(xiàn)為NAA成分無或少，Cho/Cr比例升高，可見脂肪酸族代謝,腦浸潤可發(fā)生于組織學上為良性、非典型性或間變性（惡性）腦膜瘤，有腦浸潤的腦膜瘤較易復發(fā)，伴有組織學上腦浸潤的良性腦膜瘤的臨床過程與非典型性腦膜瘤相似，但不出現(xiàn)非典型性和間變性（惡性）腦膜瘤的遺傳學（基因）改變。言外之義，腦浸潤=非典型性腦膜瘤,陳星榮。 腦膜瘤。中國醫(yī)學計算機成像雜志。2002,腦浸潤的確定性征象：腫瘤邊緣毛糙模糊，蘑菇征，偽足征（

54、腫瘤邊緣指狀突出），毛刷征，為腦浸潤的確定性征象。腦浸潤的提示性征象:腫瘤輪廓呈節(jié)結狀或分葉狀。,陳星榮。 腦膜瘤。中國醫(yī)學計算機成像雜志。2002,,,蘑菇征為腦浸潤的確定性征象,,蛛網膜浸潤:擴大蛛網膜下腔內毛刺狀增強,,血管外皮細胞瘤,大體病理許多血管外皮細胞瘤類似腦膜瘤。3／4為邊界清楚、質硬、有包膜的分葉狀腫決。可有寬或窄基底與硬腦膜聯(lián)系。血管外皮細胞瘤為含有許多穿支血管的富血供腫瘤鏡下病理可見豐富的細胞和血管形

55、成致密的彌漫的網絡結構，呈小葉狀排列的腫瘤細胞周圍繞以鹿角血管為其特征?？梢娪薪z分裂分期與分級：WHO將血管外皮細胞瘤歸為起源不明腫瘤類,CT表現(xiàn)平掃：多呈低等混合密度。其內常見囊變或壞死。骨窗顯示病灶局部侵蝕性骨質破壞增強：病灶呈不均勻強化MRI表現(xiàn)T1WI呈等信號， PDWI、 T2WI呈略高信號信號不均勻，與腫瘤壞死、囊變及腫瘤血管流空有關增強后掃描明顯不均勻強化,血管母細胞瘤,大體病理局限性邊界清晰，可見血管豐

56、富的結節(jié)，囊變鏡下病理通常囊壁壓迫腦組織而不是腫瘤實質。結節(jié)成分為大的空泡樣的基質細胞和豐富的毛細血管網分期與分級：WHO Ⅰ級,CT表現(xiàn)平掃：低密度囊＋等密度結節(jié)增強：常見：結節(jié)顯著均勻強化，囊不強化 少見：實性腫塊 罕見：環(huán)狀強化的腫塊MRI表現(xiàn)T1WI：囊腫低信號，結節(jié)等信號T2WI：高信號部分病例出現(xiàn)明顯的流空效應;結節(jié)顯著強化DSA：大的乏血管腫塊

57、（囊腫）＋血管豐富的結節(jié)（有時見動靜脈分流）,髓母細胞瘤,大體病理質硬，邊界清或質軟，邊界不清鏡下病理細胞密集，核圓或橢圓，胞質稀少。分化不好的神經外胚層細胞瘤細胞圍繞一神經纖維作放射狀排列形成典型的菊型團有絲分裂和細胞凋亡常見四種亞型：促纖維增生型，MB伴廣泛結節(jié)，大細胞型，黑色素型分期與分級：WHO Ⅳ級。,促纖維增生型MB,CT表現(xiàn)平掃：后顱凹中線的低密度實性腫塊。10％~20％伴鈣化。第四腦室向前移位增強：90

58、％以上強化。強化程度由輕度到中度,強化形式由斑片狀到均勻一致的強化MRI表現(xiàn)第四腦室中線處信號均勻的腫塊T1WI上等/低信號，T2WI等信號或低高混雜信號可見囊變，出血，壞死90％出現(xiàn)程度不同的強化50％可見腦脊液播散MRS ：NAA/Cho降低，Cr/Cho降低,Frost et al. medulloblastomas have a lateral location in 30% of cases inadults

59、 and 7% in children.Sarkar et al. lateral location was more common in adults (46.4%) as compared to childhood cases(10.7%),Frost JP, et al. Medulloblastoma in adults. Int J Radiat Oncol Biol Phys 1995;32:951–7.Sarkar

60、 C, et al. Are childhood and adult medulloblastoma different? A comparative study of clinicopathological features, proliferation index and apoptotic index. J Neuroncol 2002;59:49–61.,The classic well-defined homogeneous

61、vermian tumour with intense contrast enhancement seems to be rare in adults, whose tumours are predominantly in the cerebellar hemisphere, poorly defined and enhance less,Malheiros SM, Carrete Jr H, Stavale JN, et al. MR

62、I of medulloblastoma in adults. Neuroradiology 2003;45:463–7.,CPA 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

63、, from the viewpoint of a differential diagnosis, the most important factor is to bear in mind the possibility of a CPA medulloblastoma,Awadhesh K, et al.Cerebellopointine angle medulloblastoma. Journal of Clinical Neuro

64、science (2004) 11(1), 42–45,原發(fā)腦淋巴瘤,98％是B細胞淋巴瘤，T細胞罕見；90％在幕上，局限性多于浸潤性。20％~25％為多發(fā)病變大體病理大腦半球的單發(fā)或多發(fā)病變。中心有壞死，HIV陽性病人伴出血鏡下病理以血管為中心，環(huán)繞、浸潤血管及血管周圍間隙。有幾種亞型，其中大細胞型占近50％，核漿質比例升高,CT表現(xiàn)平掃：低密度，偶爾等密度。可出血，壞死增強：常見中度均勻強化；少見環(huán)狀強化

65、 罕見：不強化（浸潤性，與白質腦病相仿）MRI表現(xiàn)T1WI及T2WI均為與皮質等或低信號FLAIR上為高信號顯著均勻強化DWI：彌散受限MRS：NAA降低，Cho升高，可出現(xiàn)脂峰或乳酸峰,Deep location explains that seizures are less frequent than in other brain tumoursCT scans and MRI typically show i

66、n a third of cases unique or multiple periventricular, homogeneously enhancing lesions Ring-like enhancement is rare in immunocompetent patients, but atypical features can simulate inflammatory or infectious diseases

67、or other brain tumours (meningiomas) Spontaneous (or steroid-induced) disappearance of lesions is classic, hence the term ghost tumours,Anthony Behin,et al. Primary brain tumours in adultsTHE LANCET ? Vol 361 ? January

68、 25, 2003,CT 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 i

69、s less prominent than edema in malignant glioma or metastases Neuroradiological gold standard of both diagnosis as well as monitoring therapy is MRI, which shows hypointense, frequently multiple enhancing lesions in T1w