胃腸間質瘤影像學特點課件

1、胃腸間質瘤影像學特點胃腸間質瘤(GIST)2009-01-01楊梅(yngmi)第一頁，共四十六頁。胃腸間質瘤影像學特點流行病學(li xn bn xu)特點v胃腸道間質瘤（ gastrointestinal stromal tumor，GIST）是一 種少見的源于胃腸道間質細胞的腫瘤，發(fā)病率約2/10 萬，主 要發(fā)病人群在4070 歲，中位年齡58 歲，男性稍多于女性。v本病臨床表現(xiàn)及影像(yn xin) 學所見缺乏特異性，確診需要靠病理組織學及免疫組化檢測。第二頁，共四十六頁。胃腸間質瘤影像學特點組織學特點(tdin)vthe GIST cells are closely related

2、to the interstitial cells of Cajal (ICC)v組織學上可表現(xiàn)為梭形細胞型、上皮細胞型，或兩者的混 合型。v分子(fnz)學上絕大多數(shù)該腫瘤表現(xiàn)為c-kit基因的變異及少部分（約5%）患者PDGFRA基因的變異 v免疫組化絕大多數(shù)可檢測到CD117 抗體陽性，表明組織 或細胞表達c-kit 原癌基因蛋白，即屬賴氨酸激酶家族的 c-kit 原癌基因發(fā)生功能獲得性突變導致。有第三頁，共四十六頁。胃腸間質瘤影像學特點50-year-old woman with small-bowel gastrointestinal stromal tumor (GIST).Pho

3、tomicrograph of histopathologic slide shows typical GIST composed of fascicles of nondescript spindle cells. Appearance on H and E stain is similar to that of smoothmuscle tumor.第四頁，共四十六頁。胃腸間質瘤影像學特點免疫組化檢查(jinch)vThe tumours can be positive for KIT (95%), CD34 (6070%), ACAT2 (smooth muscle actin; 304

4、0%), S100 (5%), DES (desmin; 12%), and keratin (1-2%). KIT is the most specifi c and sensitive marker.。v另外，CD34（+），S-100（-），GFAP（-）有助于協(xié)助鑒別(jinbi)診斷，S-100（-）可除外神 經源性腫瘤，GFAP（-）可除外膠質瘤。第五頁，共四十六頁。胃腸間質瘤影像學特點第六頁，共四十六頁。胃腸間質瘤影像學特點臨床(ln chun)特點v最常見的間質性腫瘤，僅占胃腸道腫瘤的1-3%。好發(fā)于胃（60-70%）、小腸（1/3）、結腸/直腸（5%）、食管（2%）。還有發(fā)生

5、于網膜、腸系膜及后腹膜。v大多數(shù)間質瘤（約60-70%）為良性，且多發(fā)生于胃部。這些病灶多偶然發(fā)現(xiàn)，均可以手術切除。14的在眼底及賁門，75在胃體，11的胃竇 。v目前趨向認為小腸間質瘤有潛在惡性傾向，推測其惡性程度的主要(zhyo)指標是腫瘤的大小及細胞核分裂相數(shù)目（每50HPF 下的數(shù)目）第七頁，共四十六頁。胃腸間質瘤影像學特點vFletcher 等2認為：腫瘤直徑2 cm 和細胞核分裂相數(shù)目5/50HPF 為極低度惡性；直徑25 cm 和5/50HPF 為低度惡性；直徑510 cm 和5/50HPF 或直徑5 cm 和610/50HPF 為中度(zhn d)惡性；直徑5 cm 和5/50

6、HPF 或直徑 10 cm 和10/50HPF 為高度惡性，但也有直徑小的腫瘤發(fā)生 轉移的報道。第八頁，共四十六頁。胃腸間質瘤影像學特點v。Chiappa 等3報道胃腸間質瘤術后復發(fā)(f f)或轉移的時間是436 個月。v個別報道時間長達十幾年。第九頁，共四十六頁。胃腸間質瘤影像學特點臨床(ln chun)癥狀v臨床癥狀主要取決于腫瘤的位置及大小，且無特異性的表現(xiàn)，僅表現(xiàn)為飽脹感、消化不良、腹痛及可觸及(ch j)包塊等癥狀，偶爾癥狀由腫瘤內出血引起。 v腫瘤出血是由于潰瘍所致。第十頁，共四十六頁。胃腸間質瘤影像學特點v腫瘤常表現(xiàn)為起源于粘膜下向腔外生長的特性，很少引起腸梗阻。v十二指腸的間質

7、瘤引起梗阻性黃疸(hungdn)時易與胰腺癌相混淆。腫瘤位于Vater壺腹部。第十一頁，共四十六頁。胃腸間質瘤影像學特點鋇餐(bicn)檢查v表現(xiàn)(bioxin)為粘膜下邊緣清晰的充盈缺損。（Forty-two-year-old female with GIST at the gastroesophageal junction.）第十二頁，共四十六頁。胃腸間質瘤影像學特點CT影像學征象(zhngxing)v邊界清晰不均質的腫塊(zhn kui)v邊緣強化明顯，厚度不均，中心密度減低。v原因是由于出血、壞死、囊變。第十三頁，共四十六頁。胃腸間質瘤影像學特點Seventy-year-old mal

8、e with GIST of the stomach with liver metastases. A large intraluminal mass is seen in the stomach, with heterogenous liver metastases.第十四頁，共四十六頁。胃腸間質瘤影像學特點v很多腫瘤發(fā)現(xiàn)時已經體積很大，約5-30cm，增強CT表現(xiàn)為不均質強化、腔外生長的腫塊(Fig. 2)。v較小的原發(fā)于胃的間質瘤表現(xiàn)為明顯的強化(Fig. 3)，在小腸的原發(fā)間質瘤很少有此征象。v小腸的間質瘤發(fā)現(xiàn)時已經很大且傾向于惡性，絕大多數(shù)病灶(bngzo)發(fā)生于十二指腸。v有的較大

9、的腫瘤平掃時可發(fā)現(xiàn)出血第十五頁，共四十六頁。胃腸間質瘤影像學特點Fig. 2.48-year-old woman with small-bowel gastrointestinal stromal tumor. Axial contrast-enhanced CT scan of pelvis shows exophytic heterogeneously enhancing mass (arrow).第十六頁，共四十六頁。胃腸間質瘤影像學特點Fig. 3.30-year-old man with gastric gastrointestinal stromal tumor. Axial co

10、ntrast enhanced CT scan of upper abdomen shows intense homogenous enhancement of tumor arising from gastric wall (arrow).第十七頁，共四十六頁。胃腸間質瘤影像學特點v偶爾也會在CT上發(fā)現(xiàn)腔內的腫瘤(Fig. 4).。v口服造影劑時可發(fā)現(xiàn)粘膜下潰瘍(Fig. 5)。v還有部分腔外的間質瘤被誤診為胰腺的腫瘤或假性囊腫(Fig. 6)。腫瘤與腸管壁常僅通過一個很薄的蒂相連，要認真(rn zhn)辨認腫瘤的起源。v如果存在腸系膜轉移，轉移灶為邊界清晰、邊緣光滑，無牽拉改變(Fig.

11、7)。第十八頁，共四十六頁。胃腸間質瘤影像學特點Fig. 4.69-year-old woman with gastric gastrointestinal stromal tumor. Axial contrast-enhanced CT scan of upper abdomen shows large intraluminal component of tumor (arrow).第十九頁，共四十六頁。胃腸間質瘤影像學特點Fifty-six-year-old male with GIST of gastric fundus. Postcontrast CT shows homogenou

12、s intraluminal GIST along the lesser curve, extending into the gastrohepatic ligament.第二十頁，共四十六頁。胃腸間質瘤影像學特點Fig. 5.Gastric gastrointestinal stromal tumor (GIST).A, Axial contrast-enhanced CT scan of upper abdomen of 69-year-old woman shows large intraluminal component of tumor with pocket of gas (arr

13、ow).第二十一頁，共四十六頁。胃腸間質瘤影像學特點B, In 63-year-old woman with gastric GIST, axial contrast-enhanced CT scan of upper abdomen shows large heterogeneously enhancing tumor in stomach and ulcer filled with oral contrast agent (arrow).第二十二頁，共四十六頁。胃腸間質瘤影像學特點Fig. 6.30-year-old man with gastric gastrointestinal st

14、romal tumor.第二十三頁，共四十六頁。胃腸間質瘤影像學特點B). This tumor was originally mistaken for infected pancreatic pseudocyst.第二十四頁，共四十六頁。胃腸間質瘤影像學特點fig.776-year-old man with small-bowel gastrointestinal stromal tumor. Axial contrast- enhanced CT scan of pelvis shows smooth mesenteric metastasis (arrowheads) at presen

15、tation.第二十五頁，共四十六頁。胃腸間質瘤影像學特點v和小腸的淋巴結相同，胃腸間質瘤可以(ky)是小腸管腔瘤樣擴張。(Fig. 8).v原因：腫瘤迅速生長。 腫瘤破壞肌間神經叢。v原發(fā)腫瘤沒有鈣化，但是，在特殊化療后的轉移灶內偶爾會出現(xiàn)鈣化。第二十六頁，共四十六頁。胃腸間質瘤影像學特點Fig. 8.45-year-old man with small-bowel gastrointestinal stromal tumor.A and B, Axial contrast-enhanced CT scans of mid abdomen show large mass (arrow) ar

16、ising from small bowel, causing aneurysmal dilatation of bowel. Proximal (arrowheads) and distal segments of small bowel were of normal caliber.第二十七頁，共四十六頁。胃腸間質瘤影像學特點第二十八頁，共四十六頁。胃腸間質瘤影像學特點腫瘤如果與管腔交通，使腫瘤空洞化及竇道(du do)形成。Seventy-seven-year-old male with GIST of the ileum. Postcontrast CTshows a large in

17、tra-abdominal mass with central cavitation.第二十九頁，共四十六頁。胃腸間質瘤影像學特點v腫瘤長大過程中，邊緣光滑，僅推擠并不侵犯周圍組織及血管。這一點(y din)可以與類癌及腺癌鑒別Fifty-six-year-old male with GIST of the ileum. (a) Postcontrast CTshows 12 cm, partially necrotic primary tumour arising from the small bowel.第三十頁，共四十六頁。胃腸間質瘤影像學特點直腸結腸的間質瘤表現(xiàn)為邊界(binji)清晰

18、的壁結節(jié)，向管腔內侵犯。Seventy-seven-year-old male with rectal GIST. Postcontrast CT shows the heterogeneously enhancing mass with intraluminal extension (arrow).第三十一頁，共四十六頁。胃腸間質瘤影像學特點胃腸間質瘤的轉移(zhuny)途徑 淋巴道轉移：v到目前為止還沒有文獻有報道。v腺癌和淋巴瘤主要為淋巴道轉移。v如果發(fā)現(xiàn)(fxin)有淋巴結轉移就應該考慮其他診斷。第三十二頁，共四十六頁。胃腸間質瘤影像學特點腸系膜轉移(zhuny)v腸系膜轉移通常見于腫

19、瘤的復發(fā)，與術后腹膜種植相關。v也可與較大的小腸的間質瘤同時發(fā)現(xiàn)，胃的間質瘤較少見。v絕大多數(shù)腸系膜的病灶為中心低密度。v因為(yn wi)病灶通常較小且遠離原發(fā)病灶而漏診。(Fig. 10).v較大的病灶圍繞腸系膜血管生長，但不引起遠端機靜脈栓塞。(Fig. 11).第三十三頁，共四十六頁。胃腸間質瘤影像學特點Fig. 10.76-year-old man with small-bowel gastrointestinal stromal tumor. Axial contrast-enhanced CT scan of mid abdomen shows rounded nodule (a

20、rrowhead) in mesentery in keeping with metastases. Metastasis is far from site of resected tumor (arrow).第三十四頁，共四十六頁。胃腸間質瘤影像學特點Fifty-six-year-old male with GIST of the ileum. (a) Postcontrast CTshows 12 cm, partially necrotic primary tumour arising from the small bowel. (b) Three years later postres

21、ection of the primary tumour, peritoneal deposits are present in the right lower quadrant (arrow).第三十五頁，共四十六頁。胃腸間質瘤影像學特點Fig. 11.75-year-old woman with small-bowel gastrointestinal stromal tumor. Axial contrast-enhanced CT scan of mid abdomen shows large mesenteric mass (arrow) growing around mesente

22、ric vessels (arrowheads). There is no thrombosis of mesenteric vessels.第三十六頁，共四十六頁。胃腸間質瘤影像學特點網膜(wngm)轉移v網膜轉移較腸系膜轉移更少見。v病灶通常直徑小于2cm，均勻強化。v因為網膜是蠕動的，因此在下一次檢查時可能不在同一個位置。v腹水非常少見，多見于分子靶向治療之后，由于(yuy)藥物納稅潴留副作用造成的。第三十七頁，共四十六頁。胃腸間質瘤影像學特點Fig. 12.76-year-old man with small-bowel gastrointestinal stromal tumor.

23、Axial contrast-enhanced CT scan第三十八頁，共四十六頁。胃腸間質瘤影像學特點axial T2-weighted fat-suppressed fast spin-echo MRI (B) of pelvis show omental caking (arrows).第三十九頁，共四十六頁。胃腸間質瘤影像學特點肝轉移(zhuny)v較小的肝轉移瘤在治療前表現(xiàn)(bioxin)為富血供。v增強CT上于門脈期表現(xiàn)為均勻明顯強化；在肝靜脈期完全排空(Fig.13)。v但是，在增強圖像上并不是所有的轉移瘤同等程度強化，有的高密度，有的低密度，因為不是同一代的轉移瘤(Fig.1

24、4)。第四十頁，共四十六頁。胃腸間質瘤影像學特點Fig. 13.78-year-old woman with small-bowel gastrointestinal stromal tumor. A, Axial breath-hold 3D fat-suppressed gradient-echo MRI of liver with gadolinium shows bright homogenous enhancement of metastasis (arrow) in late arterial phase. Smaller hypovascular metastases are a

25、lso evident (arrowheads).第四十一頁，共四十六頁。胃腸間質瘤影像學特點B, In venous phase, MRI of large metastasis shows complete washout of contrast material (arrow). Smaller hypovascular metastases are also evident (arrowheads).第四十二頁，共四十六頁。胃腸間質瘤影像學特點Fig. 14.50-year-old woman with gastric gastrointestinal stromal tumor. Axial contrast- enhanced CT scan of liver rev