2017讀書報告大于cm胃間質(zhì)瘤與胃良性腫瘤的鑒別

1、讀書報告會2017,Differentiation of large (≥5 cm) gastrointestinal stromal tumors frombenign subepithelial tumors in the stomach,,CONTENTS,目錄,,1,Introduction,,2,Materials and methods,,3,Results,,4,Discussion,,5,Case,,6,Conclus

2、ion,Page 3,Case,患者：女性，61歲主訴：發(fā)現(xiàn)左上腹腫塊5年?？企w查：腹部平軟，全腹無壓痛及腹肌緊張，劍突下偏右可觸及一腫塊，大小約4×6cm,邊緣清楚，無壓痛。,Case,Page 4,Page 5,Case,Page 6,Case,免疫組化結(jié)果顯示:Bcl-2(++),CD34(+++),Calretinin ( －),EMA(±),Ki-67(+約0.9%), S-100(－),SMA(

3、－ ), CD117(+++),DOG-1(+++),CD99(++)間質(zhì)瘤,Page 7,Introduction,Like many other organs, the stomach is not only the origin of epithelial tumors and lymphomas, but also a wide range of mesenchymal tumors.

4、Approximately 3% of all gastric tumors belong to the latter group . Gastric mesenchymal tumors can be divided into four main categories; true smooth muscle tumors neurogenic tumors, fibroblastic tumors, and gas-trointes

5、tinal stromal tumors(GISTs).,Gastric mesenchymal tumors typically manifest as a sub-epithelial lesion on both imaging and pathologic exam-inations. Except in very rare leiomyosarcomas , all gastric mesenchymal tumors ot

6、her than GISTs are almost always benign. GISTs, on the other hand, even when they are small, are potentially malignant . Therefore, accurate differentiation of GISTs from other benign subepithelial tumors is crucial for

7、planning management options,Page 8,Introduction,Introduction,In this study, we attempted to determine whether there are characteristic CT features which may help differentiate GISTs from non-GISTs in patients with large

8、(≥5 cm) gastric sub-epithelial tumors. Additionally, we assessed whether radio-logists’ performance in differentiation can be improved with knowledge of these CT criteria.,Page 9,Page 10,,Materials and methods,Materials

9、 and methods,Finally, 120 patients with ≥5 cm gastric subepithelial tumors were enrolled in our study: 99 patients with GIST (57 men, 42 women; mean age, 60.4±12.9 (standard deviation (SD)) years; range, 25–85 years

10、), 16 patients with sch-wannoma (7 men, 9 women; mean age, 58.9 ±12.4 (SD) years; range, 37–83 years), and 5 patients with leiomyoma (3 men, 2 women; mean age, 42.4±13.2 (SD) years; range, 27–63 years).,Page 11

11、,Results,Page 12,Clinical and pathologic features of 120 patients with large (≥5 cm) gastric subepithelial tumors.,Results,Page 13,Page 14,Fig. 2. A 57-year old man with gastric gastrointestinal stromal tumor (GIST). (A)

12、 Arterial (left) and portal (right) phase CT images demonstrate a 9 cm huge heterogeneous,low-attenuating subepithelial mass involving the greater cur-vature side of the gastric upper thirds, showing a mixed endo- and e

13、xophytic growth pattern. There are irregular necrosis and air-density (arrows) within the mass. A surface ulceration (arrowhead) is also noted at the endoluminal surface of the mass.Enlarged lymph nodes were not observed

14、 on CT. Both radiologists correctly interpreted this lesion as a GIST during the two review sessions and their diagnostic confidence was improved from 4 (probably GIST) to 5 (definitely GIST). (B) Gross specimen obtained

15、 after proximal gastrectomy shows a 9 cm huge subepithelial tumor (arrows) with surface ulcerations (arrowheads). On a cut section (right lower corner) of the tumor, the tumor has a gray to white cut surface with foci of

16、 necrosis or hemorrhage.,Results,Page 15,Results,Fig. 3. A 55-year old woman with gastric gastrointestinal stromal tumor (GIST).(A) On portal phase CT, a 6 cm heterogeneous, low-attenuating subepithelial mass (arrows) is

17、 seen at the posterior wall of the gastric upper thirds. The lesion shows a mixed growth pattern. There is a low attenuating necrotic portion (*) within the tumor. A well-enhancing enlarged lymph node (arrowhead) is also

18、 noted at the perigastric area. Two radiologists interpreted this lesion as GIST during the two interpretation sessions and the con-fidence level was improved by one reviewer from 3 (possibly GIST) to 5 (definitely GIST)

19、. (B) Gastric wedge resection specimen shows a 6 cm subepithelial mass (arrows) with surface ulcerations (arrowheads). Microscopic examination confirmed the diagnosis of a gastrointestinal stromal tumor (not shown). Ther

20、e was necrosis and hemorrhage in the tumor and its mitotic count was 2/50 HPFs. Therefore, this lesion was categorized as having an intermediate risk of aggressive behavior. There was no malignant focus in the four resec

21、ted lymph nodes (not shown). HPF, high-power field.,Page 16,Fig. 4. A 39-year old woman with gastric schwannoma. (A, B) On portal phase CT images, an 8 cm homogeneous, low-attenuating subepithelial mass (*) is seen at th

22、e lesser curvature side of the gastric mid-body, showing a mixed endo- and exophytic growth pattern. A small surface ulceration (arrow) was noted at the endoluminal surface of the lesion. There are several enlarged and w

23、ell-enhancing lymph nodes (arrowheads) at the left gastric and perigastric areas. The tumor was interpreted as gastric GIST by both reviewers (confidence level: 4, probably GIST) at the first review session, but was reco

24、rded as schwannoma by both reviewers (confidence level: 1) at the second review session.,Results,Page 17,Results,Fig. 5. A 61-year old man with gastric schwannoma. (A) On portal phase CT scan, an 11 cm large heterogeneou

25、s iso-attenuating mass (*) is seen at the greater curvature side of the gastric mid body. There is no necrosis within the tumor or surface ulcerations.(B) Serial CT images show multiple enlarged and enhancing lymph nodes

26、 (arrowheads) at the perigastric and paraaortic areas. After wedge resection, the lesion was confirmed as a gastric schwannoma (not shown). Reactive hyperplasia was noted at four lymph nodes in the resected specimen (not

27、 shown).,Page 18,Fig. 6. A 49-year old man with gastric leiomyoma. (A) Arterial and portal phase CT images demonstrate a 6 cm homo-geneous and low-attenuating subepithelial mass (*) involving the gastric cardia and gastr

28、o-esophageal junction (arrows). The lesion shows an endophytic growth pattern. There is no intratumoral necrosis, calcification, and surface ulcerations. No enlarged lymph nodes were observed. Both radiologists’ diagnost

29、ic confidence was improved from 2 (probably non-GIST) to 1 (definitely non-GIST) during the two successive review sessions. (B) Gross specimen obtained after wedge resection shows an elongated subepithelial tumor (arrows

30、). On a cut section (right lower corner) of the tumor, the tumor has a gray to white, whirling cut surface without foci of necrosis or hemorrhage.,Results,Discussion,In this study, none of the gastric schwannomas and lei

31、om-yomas except one schwannoma showed intra-tumoral necrosis. gastric leiomyomas seldom accompany with intra-tumoral necrosis. This should not be surprising considering the relatively slow speed of tumor growth in benign

32、 tumors which is typically on par with that of neovascularization.,Page 19,Discussion,Conversely, in malignant tumors such as GIST, the speed of tumor growth often outstrips that of neovascularization leading to central

33、 necrosis. Even though the presence of necrosis at the center of the tumor is a well-known imaging feature of GISTs, particularly large GISTs [5–7], the absence of necrosis in gastric schwannomas on imaging studies has n

34、ot been emphasized in previous studies [10,11].,Page 20,Discussion,We believe that the results of this study suggest and con-firm that the presence of necrosis is a differentiating CT feature of GIST which has already be

35、en well-established in the pathologic field.,Page 21,Discussion,In other words, the presence of enlarged lymph nodes is a highly specific CT finding for gastric schwannoma according to our study results. In our study, 75

36、% (12/16) of large schwannomas had enlarged lymph nodes whereas only 5.1% (5/99) of large GISTs had lymphadenopathy.,Page 22,Discussion,Our study demonstrated that gastric leiomyomas were exclusively located at the car

37、dia of the stomach.,Page 23,Conclusion,In conclusion, heterogeneous enhancement and presence of necrosis are CT findings highly suggestive of large GISTs in differentiation from large gastric schwannomas or leiomyomas.