病理與臨床特點(diǎn)

大腦膠質(zhì)瘤病( gliomatosis cerebri,GC)2007 年被列入星形細(xì)胞起源腫瘤,特點(diǎn)是腫瘤細(xì)胞極度彌漫性浸潤,正常結(jié)構(gòu)相對保存,不形成肉眼可見的腫塊,WHO 為Ⅱ-IV 級(jí),多數(shù)為Ⅲ級(jí)。曾稱為彌漫性膠質(zhì)瘤(diffuse glioma)、彌漫性中樞神經(jīng)鞘病(diffuse central schwannosis)及彌漫性大腦膠質(zhì)瘤病(diffuse cerebral lipomatoSis)1938年 Nevin 首次提出GC 的命名。GC 作為一獨(dú)立疾病已從 2016年 WHO 新分類中刪去,認(rèn)為是多種膠質(zhì)瘤的生長方式,見于 IDH 突變的星形細(xì)胞瘤和少突膠質(zhì)細(xì)胞瘤以及 IDH 野生型的膠質(zhì)母細(xì)胞瘤,即現(xiàn)在認(rèn)為是多種彌漫型膠質(zhì)瘤亞型的特殊類型。腫瘤呈浸潤性生長,腦結(jié)構(gòu)仍保留,大體病理難以辨認(rèn)腫瘤邊界。鏡下腫瘤由中等密集程度圓形或拉長的瘤細(xì)胞組成,分化程度不同,染色質(zhì)豐富,偶見間變。灰白質(zhì)內(nèi)均見瘤細(xì)胞,但解剖結(jié)構(gòu)仍存在,腫瘤細(xì)胞沿神經(jīng)元周圍、血管周圍及柔腦膜下浸潤。部分病例 GFAP及 S-100 染色陽性。發(fā)病高峰年齡為 20~50歲,無明顯性別差。臨床表現(xiàn)無特異性,包括智力下降及人格改變。本病預(yù)后不良,中位生存期14個(gè)月?；熆赡転楸静∮行У氖走x治療方法。

Brain glioma disease (gliomatosis cerebri, GC) in 2007 was listed in astrocytes on the origin of tumor, is characterized by diffuse infiltration of the tumor cells are, normal structure relative to save, do not form visible lump, WHO is Ⅱ - level IV, mostly Ⅲ level. GC was first named by Nevin in 1938 after diffuse glioma and diffuse central schwannosis and diffuse lipomatoSis of the brain. GC, as an independent disease, has been deleted from the new classification of WHO in 2016 and is considered to be the growth mode of a variety of gliomas, which can be seen in astrocytomas and oligodendrogliomas with IDH mutations and glioblastomas with IDH wild-type glioblastomas, which are now considered to be special types of a variety of diffuse glioma subtypes. The tumor showed invasive growth, and the brain structure remained. Microscopically, the tumor consists of moderately dense rounded or elongated tumor cells with varying degrees of differentiation, rich chromatin, and occasional interchanges. Tumor cells were found in the gray matter, but the anatomical structure was still present. Tumor cells infiltrated along the periphery of neurons, blood vessels and submeninges. GFAP and s-100 were positive in some cases. The peak age of the disease was 20~50 years old, and there was no significant gender difference. Clinical manifestations are not specific, including intellectual decline and personality changes. The prognosis is poor and the median survival is 14 months. Chemotherapy may be the first effective treatment for this disease.

CT與 MRI 特點(diǎn)

①部位與形態(tài):可侵犯腦各部位,但 3/4 位于大腦半球,丘腦與基底核常受累,半數(shù)病例同時(shí)侵犯中腦,腦橋、小腦及延髓也可受侵。腫瘤范圍廣,累及3 個(gè)腦葉以上,邊界不清。病變處腦回增粗及腦溝裂變淺;

(1)location and morphology: can invade all parts of the brain, but 3/4 is located in the cerebral hemisphere, thalamus and basal ganglia are often involved, half of the cases also invade the midbrain, pons, cerebellum and medulla oblongata can also be invaded. The tumor was extensive and involved more than 3 lobes of the brain. Thickening of gyri and shallow fissions in sulcus;

②CT 檢查為等或低密度,常難以分辨,間接征象為局部腦腫脹、灰白質(zhì)界面消失,可形似血管病或代謝中毒性疾病。增強(qiáng)掃描多無強(qiáng)化,少數(shù)病例晚期可見模糊的斑片狀或環(huán)狀強(qiáng)化;

(2)CT examination is equal or low density, often difficult to distinguish, indirect signs for local brain swelling, gray matter interface disappeared, can be shaped like vascular disease or metabolic toxic diseases. There was no enhancement in most of the enhanced scans, and there were some fuzzy patchy or annular enhancement in the late stage in a few cases.

③T1WI 表現(xiàn)為境界不凊的等或稍低信號(hào),腦回增粗,灰白質(zhì)界面欠清。T2WI及FLAIR 為彌漫性高信號(hào),界限不清,有時(shí)內(nèi)部見少許更高信號(hào)。DWI 一般無擴(kuò)散受限,少數(shù)為輕中度高信號(hào),DTI顯示纖維束無破壞。MRS近似正常,或見Cho與mI增高及NAA下降。增強(qiáng)掃描約半數(shù)病例出現(xiàn)局限性或彌漫性輕中度強(qiáng)化,呈斑片狀,強(qiáng)化區(qū)代表該處腫瘤級(jí)別較高。原發(fā)于腦膜GC可見腦膜異常增厚及強(qiáng)化,形似腦膜癌病。

(3)T1WI of state not part or slightly low signal, such as enlargement of gyri, gray matter interface. T2WI and FLAIR are diffuse hyperintensity, with blurred boundaries and sometimes a few higher signals inside. DWI generally has no diffusion limitation, and a few are light to medium high signals. DTI shows no damage to fiber bundles. MRS was approximately normal, or Cho and mI increased and NAA decreased. About half of the cases presented localized or diffuse mild to moderate enhancement in the enhanced scan, which was patchy, and the enhanced area represented higher tumor grade. Abnormal thickening and enhancement of the meninges, similar to meningeal carcinomatosis, were observed by GC。

鑒別診斷  

需與多種彌漫性病變鑒別。

①多發(fā)性硬化,病灶一般多發(fā),但較局限,增強(qiáng)掃描可見開環(huán)狀強(qiáng)化,臨床特點(diǎn)為癥狀反復(fù)發(fā)作與進(jìn)行性加重;

(1)multiple sclerosis, lesions generally multiple, but more limited, enhanced scan can be seen open ring enhancement, clinical characteristics of recurrent symptoms and progressive aggravation;

②腦炎與本病鑒別困難,但腦炎可有前驅(qū)病毒感染,臨床上有發(fā)熱及腦脊液異常等;

(2)encephalitis and the disease is difficult to identify, but encephalitis can have progenitor virus infection, clinical fever and cerebrospinal fluid abnormalities;

③線粒體腦肌病,反復(fù)中風(fēng)樣發(fā)作,但病變常為非血管性分布,MRA 顯示血管正?；蜉p度異常,MRS顯示Lac 增高。肌肉活檢可確診;

(3)mitochondrial encephalomyopathy, repeated stroke-like attacks, but the lesions were usually nonvascular distribution,MRA showed normal or mild abnormalities of blood vessels, and MRS showed increased Lac. Muscle biopsy can be confirmed;

④腦缺血及動(dòng)脈硬化性腦病,前者常為某一動(dòng)脈分布區(qū)異常,急性發(fā)病,DWI及 MRA 可見明顯異常;后者以幕上腦皮質(zhì)下白質(zhì)及腦室周圍為著,對稱分布,不累及腦皮質(zhì);

(4)cerebral ischemia and arteriosclerotic encephalopathy, the former is often an abnormal artery distribution area, acute onset,DWI and MRA can be clearly abnormal; The latter was distributed symmetrically in the supratentorial subcortical white matter and around the ventricle, and did not involve the cerebral cortex.

⑤腎上腺腦白質(zhì)營養(yǎng)不良為遺傳性疾病,典型影像學(xué)表現(xiàn)為累及三角區(qū)周圍白質(zhì)的蝴蝶狀異常密度及信號(hào),增強(qiáng)掃描可見病變中帶強(qiáng)化;

(5)adrenal and cerebral leukodystrophy is a genetic disease, and the typical imaging manifestations are abnormal butterfly density and signal of white matter around the triangle region, which can be seen in enhanced scan.

⑥亞急性硬化性全腦炎為麻疹病毒介導(dǎo)腦炎,病變對稱累及頂葉與枕葉,T1WI 低信號(hào),T2WI 彌漫性高信號(hào),增強(qiáng)掃描無強(qiáng)化。

(6)Subacute sclerosing panencephalitis is measles virus mediated encephalitis, lesions symmetric involving the parietal lobe and occipital lobe,T1WI low signal,T2WI diffuse high signal, enhanced scanning without enhancement.

簡要討論

GC 的特點(diǎn)是至少累及3個(gè)腦葉,通常侵犯基底核與大腦深部白質(zhì),影像學(xué)表現(xiàn)明顯,而臨床癥狀相對較輕,病變進(jìn)展緩慢,腫瘤內(nèi)可并存多種級(jí)別的腫瘤性星形細(xì)胞,因此活檢有可能低估腫瘤級(jí)別,應(yīng)在功能MRI(如MRS)指導(dǎo)下進(jìn)行取材。

GC is characterized by involvement at least three lobes, usually infringement of basal ganglia and deep brain white matter, imaging findings, and clinical symptoms are relatively mild, pathological changes slowly, tumor can coexist in a variety of levels of tumor astrocytes, therefore biopsy may underestimate the level of tumor, should be under the guidance of functional MRI (MRS) of materials.