蔣玲君,徐曉曉,張道春
(1.浙江省臺(tái)州市路橋區(qū)第三人民醫(yī)院,浙江 臺(tái)州 318056;2.浙江省臺(tái)州恩澤醫(yī)療中心(集團(tuán))路橋醫(yī)院放射科,浙江 臺(tái)州 318050)
肝臟炎性肌纖維母細(xì)胞瘤的CT表現(xiàn)與病理對(duì)照
蔣玲君1,徐曉曉2,張道春2
(1.浙江省臺(tái)州市路橋區(qū)第三人民醫(yī)院,浙江 臺(tái)州318056;2.浙江省臺(tái)州恩澤醫(yī)療中心(集團(tuán))路橋醫(yī)院放射科,浙江 臺(tái)州318050)
目的:探討肝臟炎性肌纖維母細(xì)胞瘤(HIMT)的CT表現(xiàn),以提高對(duì)本病的認(rèn)識(shí)。材料和方法:回顧性分析本院經(jīng)病理證實(shí)的6例HIMT的臨床資料及CT表現(xiàn),其中男4例,女2例;年齡48~59歲,平均43歲。6例均行CT平掃及動(dòng)態(tài)增強(qiáng)掃描。結(jié)果:6例中,5例單發(fā),1例多發(fā);邊界不清4例,邊界清晰2例;肝左葉3例,右葉2例,跨肝左、右葉1例。CT平掃均表現(xiàn)為低密度影,密度均勻者2例,密度不均者4例;動(dòng)態(tài)增強(qiáng)掃描動(dòng)脈期無(wú)明顯強(qiáng)化2例,輕-中度強(qiáng)化4例;門脈期呈進(jìn)一步中-重度強(qiáng)化6例,延遲期呈持續(xù)性強(qiáng)化5例,強(qiáng)化程度下降1例。另動(dòng)脈期病變內(nèi)見供血?jiǎng)用}1例,周圍見斑片狀異常強(qiáng)化1例;合并肝內(nèi)膽管擴(kuò)張1例。結(jié)論:HIMT的CT表現(xiàn)多樣,動(dòng)態(tài)增強(qiáng)掃描可充分反映病變的病理學(xué)特征,結(jié)合臨床資料,應(yīng)考慮到本病的可能;但最終確診仍依賴于病理和免疫組織學(xué)檢查。
肝腫瘤;腫瘤,肌組織;體層攝影術(shù),螺旋計(jì)算機(jī)
炎性肌纖維母細(xì)胞瘤 (Inflammatory myofibroblastic tumor,IMT)是以纖維結(jié)締組織增生伴大量炎性細(xì)胞浸潤(rùn)形成的一種少見的中間性腫瘤;常見的發(fā)病部位是肺,發(fā)生于肝臟者甚為罕見,最早由Pack于1953首次報(bào)道[1]。 筆者搜集本院2005年7月—2014年9月6例經(jīng)手術(shù)病理證實(shí)的肝臟IMT(HIMT)的影像學(xué)及臨床資料,旨在分析、總結(jié)本病的CT表現(xiàn)特征,從而增加對(duì)本病的認(rèn)識(shí),提高術(shù)前診斷準(zhǔn)確率。
1.1研究對(duì)象
6例HIMT中男4例,女2例;年齡48~59歲,平均43歲;臨床表現(xiàn)為上腹部疼痛、不適2例;腹脹、納差1例;體質(zhì)量下降1例,另2例為體檢偶然發(fā)現(xiàn)。6例患者均無(wú)肝炎、肝硬化病史,肝功能檢查均無(wú)異常,腫瘤標(biāo)志物如AFP、CEA均為陰性。
1.2檢查方法
采用Siemens Esprit螺旋CT掃描儀,行CT平掃+三期動(dòng)態(tài)增強(qiáng)掃描。掃描參數(shù):130 kV,120 mAs,層厚5mm,層間距5mm,螺距1.8mm。增強(qiáng)掃描使用非離子型對(duì)比劑碘海醇 (350 mgI/mL)1.0~1.5 mL/kg,流率為2.5~3.5 mL/s,注射對(duì)比劑25 s、60 s及120 s分別行動(dòng)脈期、門脈期及延遲期掃描。
2.1CT表現(xiàn)
本組6例中,肝左葉3例,肝右葉2例,同時(shí)累及肝左、右葉1例;5例單發(fā),1例多發(fā);病變呈類圓形5例,結(jié)節(jié)狀及斑片狀1例;邊界不清4例,邊界清晰2例;范圍約17 mm×20 mm~57 mm×47 mm。CT平掃6例均呈低密度(圖1a,2a,3a),其中4例密度不均,病變中心可見更低密度區(qū)。動(dòng)態(tài)增強(qiáng)掃描動(dòng)脈期無(wú)明顯強(qiáng)化2例,輕-中度強(qiáng)化4例;門脈期呈進(jìn)一步中-重度強(qiáng)化6例;延遲期呈持續(xù)性強(qiáng)化5例,其中,2例見“靶征”(圖1b~1d),即病變中心可見類圓形、斑片狀低密度區(qū),外周帶呈等、稍高密度影,最外周為低密度影環(huán)繞,增強(qiáng)掃描病變中心低密度區(qū)始終無(wú)強(qiáng)化,外周帶呈不同程度延遲性強(qiáng)化;延遲期強(qiáng)化程度下降1例(圖2d)。另動(dòng)脈期病變內(nèi)見供血?jiǎng)用}伸入1例(圖3b),周圍見斑片狀異常強(qiáng)化區(qū)1例(圖3c);合并肝內(nèi)膽管擴(kuò)張1例。
2.2病理表現(xiàn)
本組6例表現(xiàn)為良性或低度惡性腫瘤。腫瘤大體觀呈實(shí)性腫塊或息肉樣腫物。光鏡下腫瘤組織由增生的肌纖維母細(xì)胞、纖維母細(xì)胞及炎細(xì)胞構(gòu)成,其中可見大量的漿細(xì)胞、淋巴細(xì)胞浸潤(rùn)。免疫組化顯示Vimentin、SMA均為陽(yáng)性或強(qiáng)陽(yáng)性表達(dá),ALK、CD-68部分陽(yáng)性表達(dá),其他標(biāo)記物 S-100、CD117和CD34均為陰性。
圖1a~1d 女,43歲,肝右前葉IMT。圖1a:CT平掃示肝右前葉類圓形低密度影,邊界尚清,密度不均,中心見斑片狀更低密度壞死區(qū);圖1b~1d:增強(qiáng)掃描示病變內(nèi)見“靶征”形成,圖1b,1c:動(dòng)脈期及門脈期示病變內(nèi)更低密度壞死區(qū),無(wú)明顯強(qiáng)化,稍外周帶呈輕-中度強(qiáng)化,最外周帶呈輕度強(qiáng)化,其中,門脈期強(qiáng)化程度略高于動(dòng)脈期;圖1d:延遲期示病變內(nèi)低密度影始終無(wú)強(qiáng)化;稍外周帶仍呈持續(xù)性強(qiáng)化,最外周帶呈明顯延遲性強(qiáng)化。Figure 1a~1d. Female,43 years old. IMT in the right anterior lobe of liver.Figure 1a:A round hypo-densitymasswith some patchy necrosis and defined border in right anterior lobe of the liver were shown in the precontrasted enhancement CT images.Figure 1b~1d:A“target sign”was shown in the lesion in the post-contrasted enhancement CT scan.Figure 1b,1c:In the arterial and portal phase,the mass with no clear enhancement in the necrosis lesion and mild/moderate enhancement around the lesion.Otherwise,the enhancement of the lesion in portal phase was more obvious.Figure 1d:The outside segment of lesion was shown obvious enhancement in the delayed phase,but the inside necrosis segment was still no enhancement.
2002年WHO軟組織腫瘤新分類中對(duì)IMT進(jìn)行了正確定義:即是由分化的肌纖維母細(xì)胞性梭形細(xì)胞組成,并常伴大量漿細(xì)胞和(或)淋巴細(xì)胞的一種腫瘤;并將其歸為纖維母細(xì)胞/肌纖維母細(xì)胞腫瘤;中間性,少數(shù)可轉(zhuǎn)移類[2]。從而避免了與其之前一些命名的混淆,如:炎性假瘤、漿細(xì)胞肉芽腫、組織細(xì)胞瘤等。IMT是一種少見的間葉源性腫瘤,其發(fā)病機(jī)制尚不明確,部分可發(fā)生于手術(shù)或創(chuàng)傷后,有研究認(rèn)為,IMT最初可能是人體對(duì)炎癥的一種異常或過度反應(yīng),最終激活具有增殖潛能的肌纖維母細(xì)胞顯著增生或失控性生長(zhǎng)形成腫瘤性病變[3-4]。
3.1臨床特點(diǎn)
IMT好發(fā)于肺部,亦可發(fā)生于肺外軟組織、頭頸、腹部臟器、縱隔及生殖道等;但原發(fā)于肝臟IMT極為罕見。HIMT臨床表現(xiàn)無(wú)明顯特異性,部分患者僅在體檢時(shí)偶然發(fā)現(xiàn);常見臨床表現(xiàn)有:發(fā)熱、上腹部疼痛、嘔吐,體質(zhì)量減輕等;絕大多數(shù)患者無(wú)肝炎、肝硬化病史,肝功能多正常,腫瘤標(biāo)志物如AFP、CEA多為陰性。本組患者臨床表現(xiàn)主要有:上腹部疼痛、腹脹、納差,體質(zhì)量下降等,肝功能均無(wú)明顯異常,與文獻(xiàn)報(bào)道基本一致。
圖2a~2e 女,49歲,肝左內(nèi)葉IMT(箭頭)。圖2a:CT平掃示肝左內(nèi)葉類圓形低密度影,邊界不清,密度均勻;圖2b:增強(qiáng)掃描動(dòng)脈期病變呈輕度不均勻強(qiáng)化,相對(duì)于肝實(shí)質(zhì)仍呈稍低密度影;圖2c:門脈期呈進(jìn)一步持續(xù)性強(qiáng)化,強(qiáng)化范圍略擴(kuò)大,以周邊強(qiáng)化為主,呈相對(duì)稍高密度影,內(nèi)見斑片狀稍低密度區(qū);圖2d:延遲期病變強(qiáng)化程度下降,呈相對(duì)稍低密度影。圖2e:病變內(nèi)見纖維組織細(xì)胞增生,及少許淋巴樣細(xì)胞浸潤(rùn),并伴有多量泡沫狀細(xì)胞灶性增生,形成結(jié)節(jié)狀結(jié)構(gòu)(HE)。Figure 2a~2e. Female,49 years old.IMT in the left medial lobe of liver(arrow).Figure 2a:A round homogeneous hypo-density mass with unclear border in the left medial lobe of liver was shown in the pre-contrasted CT scan.Figure 2b:In the arterial phase,the lesion was shown mild heterogeneous enhancement lower density relative to liver.Figure 2c:In the portal phase,the lesion was shown continued heterogeneous enhancement with some no enhanced low density inside.The enhanced area was larger and then shown hyper-density.Figure 2d:In the delayed phase,the enhancement of the lesion was decreasing and its density was lower than the liver.Figure 2e:HE.There were hyperplastic fibrous tissue cells and a few lymphoid cells,accompanied foamy cells formed a nodular structure in the lesion.
圖3a~3c 女,59歲,肝右后葉IMT。圖3a:CT平掃示肝右后葉類圓形低密度影,密度均勻,邊界欠清;圖3b:動(dòng)脈期肝右后葉見一迂曲血管伸入病變內(nèi)(箭頭);圖3c:動(dòng)脈期示病變呈中度不均勻強(qiáng)化,周圍見斑片狀明顯異常強(qiáng)化區(qū)(箭頭)。Figure 3a~3c. Female,59 years old.IMT in the right posterior lobe of liver.Figure 3a:A round hypo-density mass with homogeneous density and unclear border in the right posterior lobe of liver was shown in the pre-contrasted CT scan.Figure 3b:In the arterial phase,there was a right hepatic artery branch crossed the lesion(arrow).Figure 3c:In the arterial phase,the lesion with moderate heterogeneous enhancement and obvious abnormal enhancement around it was shown in the lesion(arrow).
3.2病理特點(diǎn)
HIMT是以肝臟局部非肝實(shí)質(zhì)細(xì)胞成分炎性增生形成瘤樣結(jié)節(jié)為主要病理特征。大體上病灶可表現(xiàn)為孤立性結(jié)節(jié)或多個(gè)結(jié)節(jié)融合,部分有完整包膜;剖面呈灰白色或黃白色,部分可見出血、壞死,少數(shù)可有中央疤痕。鏡檢可見不同數(shù)量的纖維母細(xì)胞及毛細(xì)血管代替正常的肝臟組織,其間散在有較多增生組織細(xì)胞、多克隆細(xì)胞,亦可有淋巴細(xì)胞、嗜酸性粒細(xì)胞等慢性炎性細(xì)胞浸潤(rùn)。其鏡下表現(xiàn)與疾病的演變過程相符合:病變初期會(huì)出現(xiàn)大量的炎細(xì)胞、肉芽組織及壞死;隨著病變進(jìn)展,膠原纖維增多,最后可出現(xiàn)膠原團(tuán)。免疫組化常表達(dá)Vimentin、SMA、MSA,部分病例 Desmin陽(yáng)性,S-100、myoglobin、CD34陰性[5]。
3.3影像學(xué)表現(xiàn)
HIMT可發(fā)生于任何年齡,以青壯年居多,男性多于女性;可單發(fā)或多發(fā),以肝右葉多見。本組6例中,男4例,女2例,平均年齡43歲;肝左葉3例,肝右葉2例,同時(shí)累及肝左、右葉1例;其中1(1/6)例多發(fā);本組發(fā)病年齡及部位與文獻(xiàn)報(bào)道不完全相符,可能與病例數(shù)較少有關(guān)。
CT平掃常表現(xiàn)為邊界清或不清低密度影,密度均勻或不均勻,鈣化少見。根據(jù)病變不同的病理發(fā)展階段,HIMT可表現(xiàn)為不同的CT動(dòng)態(tài)增強(qiáng)表現(xiàn),無(wú)明顯特異性。筆者學(xué)習(xí)本組6例HIMT CT動(dòng)態(tài)增強(qiáng)表現(xiàn)并結(jié)合相關(guān)文獻(xiàn)復(fù)習(xí)[6],總結(jié)如下:①HIMT動(dòng)態(tài)增強(qiáng)掃描常見表現(xiàn)有:動(dòng)脈期不強(qiáng)化或輕度強(qiáng)化,門脈期強(qiáng)化較動(dòng)脈期明顯,這與病變主要由門靜脈供血,肝動(dòng)脈供血較少有關(guān);延遲期呈持續(xù)性強(qiáng)化,強(qiáng)化范圍進(jìn)一步擴(kuò)大,呈等、稍高密度影;病變內(nèi)常可見斑點(diǎn)、片狀低密度不強(qiáng)化區(qū),部分可見“靶征”形成,即病變中心可見類圓形、斑片狀低密度區(qū),外周帶呈等、稍高密度影,最外周為低密度影環(huán)繞,增強(qiáng)掃描病變中心低密度區(qū)始終無(wú)強(qiáng)化,外周帶呈不同程度延遲性強(qiáng)化;本組可見2(2/6)例,與病灶中心為散在斑點(diǎn)狀、片狀凝固性壞死,而周圍多為環(huán)帶狀纖維組織包裹及炎性細(xì)胞浸潤(rùn)的病理基礎(chǔ)相對(duì)應(yīng);其中,低強(qiáng)化區(qū)以纖維組織細(xì)胞浸潤(rùn)為主,而高強(qiáng)化區(qū)以炎性細(xì)胞(包括泡沫組織細(xì)胞、漿細(xì)胞及淋巴細(xì)胞等)浸潤(rùn)為主。另增強(qiáng)掃描動(dòng)脈期部分病變周圍可見斑片狀強(qiáng)化,經(jīng)病理證實(shí)其血管內(nèi)皮細(xì)胞標(biāo)記物CD34(+)[7],本組中可見1(1/6)例。②HIMT動(dòng)態(tài)增強(qiáng)掃描少見表現(xiàn)有:動(dòng)脈期呈輕度強(qiáng)化,門脈期呈進(jìn)一步強(qiáng)化,強(qiáng)化程度較動(dòng)脈期明顯,范圍略擴(kuò)大,延遲期病變強(qiáng)化程度下降,呈相對(duì)稍低密度影;筆者推測(cè)可能與病變內(nèi)纖維組織成分相對(duì)較少,造影劑廓清較快有關(guān);本組僅1例(1/6)見此類似表現(xiàn),與Liu等[8]報(bào)道相一致。
3.4鑒別診斷
HIMT需與肝膿腫、肝轉(zhuǎn)移瘤、肝內(nèi)膽管細(xì)胞癌及原發(fā)性肝細(xì)胞癌等相鑒別。①肝膿腫起病急,常有腹痛、發(fā)熱及白細(xì)胞升高等癥狀,病灶內(nèi)常見多房、分隔狀改變,外周水腫帶無(wú)延遲性強(qiáng)化;但當(dāng)其外周帶有肉芽組織形成時(shí)二者難以鑒別;且肝膿腫可向HIMT轉(zhuǎn)歸,即所謂假瘤樣肝膿腫。②肝轉(zhuǎn)移瘤常多發(fā),并有原發(fā)腫瘤病史,病灶周圍少見低密度環(huán)及延遲性強(qiáng)化改變等。③肝內(nèi)膽管細(xì)胞癌亦可表現(xiàn)為動(dòng)態(tài)增強(qiáng)早期輕度強(qiáng)化,門脈期、延遲期呈持續(xù)性輕中度強(qiáng)化;但膽管細(xì)胞癌常以肝左葉多見,并??梢娻徑伪荒ぐ櫩s,病灶內(nèi)或周邊??梢娔懝軘U(kuò)張,管壁增厚等征象。④原發(fā)性肝細(xì)胞癌,典型者容易鑒別;但對(duì)于少數(shù)不典型者,如少血供者或有門靜脈參與供血者,其強(qiáng)化形式常與HIMT重疊,二者鑒別較困難;因此,常需要結(jié)合臨床有無(wú)肝炎、肝硬化病史及AFP的測(cè)定等進(jìn)行輔助診斷。
3.5治療及預(yù)后
HIMT是肝臟偏良性腫瘤,發(fā)展緩慢,極少發(fā)生惡變;大部分患者經(jīng)激素或抗生素治療后腫塊可縮小或消失;而對(duì)于術(shù)前不能完全除外肝臟其他惡性腫瘤,經(jīng)激素、抗生素等藥物治療無(wú)效或病情進(jìn)展者,則應(yīng)積極采取手術(shù)治療。由于HIMT是一種惰性腫瘤,且患者很少合并肝炎、肝硬化等病史,因此其預(yù)后良好,患者可長(zhǎng)期存活。
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Comparison with CT imaging features and pathologic findings of hepatic inflammatory myofibroblastic tumor
JIANG Ling-jun1,XU Xiao-xiao2,ZHANG Dao-chun2
(1.Luqiao District of Taizhou City Third People's Hospital,Taizhou Zhejiang 318056,China;2.Department of Radiology,Taizhou Enze Medical Center(Group)Luqiao Hospital,Taizhou Zhejiang 318050,China)
Objective:To evluate the CT imaging features of hepatic inflammatory myofibroblastic tumor(HIMT),so as to improve its diagnostic accuracy.Materials and Methods:The clinical and CT imaging findings of 6 cases of HIMT which confirmed by pathology in our hospital were analyzed retrospectively,including 4 males and 2 females,aged from 48 to 59 years old,mean age was 43 years old.Pre-and post-contrast CT images were examined for all six cases.Results:Five of six cases were single lesion,the other one was multiple.Clear margin was in four cases and unclear margin in two cases. Three cases were located in the left lobe of liver,2 cases were in the right lobe of the liver and 1 case was located both the left and right lobe.In the pre-contrasted enhancement CT scan,heterogeneous(n=2)or homogeneous(n=4)hypo-density were shown in six cases.No enhancement(n=2)or mild/moderate enhancement(n=4)was shown in arterial phase respectively. Delayed enhancement was shown in the portal phase(n=6)and the delayed phase(n=5).Moreover,on the arterial phase image,feeding artery were shown in one case,having patchy enhancement around it in one case.The dilatation of the intra-hepatic bile duct was seen in one case.Conclusion:The dynamic contrast enhancement CT features of HIMT are multiple characteristic,which correlate with its pathologic findings.But the final diagnosis relies on pathology and immunohistochemistry examination.
Liver neoplasms;Neoplasms,muscle tissue;Tomography,spiral computed
R735.7;R730.262;R814.42
A
1008-1062(2015)07-0487-04
2014-12-16;
2015-01-20
蔣玲君(1977-),女,浙江臺(tái)州人,主治醫(yī)師。