The Study Of Radiological Features Of Colonic Metastases From Gastric Cancer And The Pathological Findings Of Primary Gastric Cancer

Part One The radiological features of colorectai metastases from gastriccancer on double-contrast barium enemaPurpose: to analyze X-ray barium enema manifestations of colorectal metastasisfrom gastric cancer, and investigate the clinical and pathological characteristics andmechanism of occurrence and development of metastasis.Subject and methods: The history of one hundred and four patients who receivepreoperative routine radiological examination as suffering from gastric cancer or whobe examined because of being diagnosed recurrences or metastases of gastric cancerpostoperatively was reviewed, and the imaging findings of barium enema wereanalyzed.The primary gastric cancer were conformed by operation pathology or endoscopebiology, with imaging of gastric barium examination, plane and contrast enhancedMSCT as well as pictures of gastric endoscope. The diagnostic criteria of colorectalmetastasis from gastric cancer are: surgical pathology, exploratory abdominal operationbiopsy, ascetic cytology, concomitant clinical and radiological signs of the disease,with clinical exclusion of metastasis from the organs other then stomach, as well as thepathological conditions other then metastasis.The imaging findings were evaluated the following: Sex, the age of colorectalmetastasis initially is found, and the duration between the time which gastric cancer was found and the time which colorectal metastasis was revealed. Findings of gastricbarium examination, surgical pathology or endoscope biology. Imaging findings wereevaluated with an emphasis on morphology, histology, lymph node invasion, peritonealimplant, ascites cytology and metastasis to liver and spleen. In evaluating the findingsof barium enema, the large bowel was divided into rectum, sigmoid, descending,transverse, ascending and cecum. And further detailed segmentation of large bowelwere divided into rectum as Rb, Ra and Rs, sigmoid to Sp and So (p: pectoral half, o:oral half), descending colon to Dp and Do, spleen flexure, hepatic flexure, Th (onethird of hepatic side of transverse colon), Tm (middle one third of transverse colon),Ts(one third of spleen side of transverse colon), ascending colon to Ap and Ao, andcecum.The constriction of bowel lumen was graded as five following degrees: grade 0:no observable constriction, grade 1: constriction＜1/3, grade 2 constriction between1/3 and 2/3, grade 3: constriction＞2/3, and grade 4: obstructed. The deformation ofbowel lumen was designed as single side and bilateral. The changes of mucosa reliefwere designed as parallel tethered folds, granular changes, compression and diffusedchange.Results: There are 67 males and 37 females in 104 patients suffering from thecolorectal metastasis from gastric cancer, with the youngest 22 years old and oldest 89years old, and there are 63 patients whose age between 56 and 75 years old. Theinterval between the detection of the primary gastric cancer and colorectal metastasisrange from 0 to 128 months, with most (91.3%) in 36 months, including 32 cases inwhich colorectal metastasis found in the routine examination before gastric operation.The morphology of the primary gastric carcinoma was Borrmann 4 (n=65),Borrmann 3 (n=28), Borrmann 2 (n=9) and early cancer (n=2). The histology waspoorly differentiated adenocarcinoma (n=44), poorly differentiated adenocarcinomawith signet-ring cell carcinoma (n=27), signet-ring cell carcinoma (n=10), poorlydifferentiated adenocarcinoma with moderately differentiated adenocarcinoma (n=11),moderately differentiated adenocarcinoma (n=7), well differentiated adenocarcinoma(n=3), papillary adenocarcinoma (n=1) and undifferentiated carcinoma (n=1). The involved sites of colorectal metastasis were transverse colon (83), rectum (50),descending colon (20), sigmoid colon (17), ascending colon (15) and cecum (1). Withdetailed segmentation, the occurrence of involvement was Tm (47), Ts (44), Th (39)and Ra (39).The constriction of bowel lumen was evaluated on the barium enema. There were19 lesions with no observable constriction, 104 lesions with constriction＜1/3, 110lesions with constriction between 1/3 and 2/3, 96 lesions with constriction＞2/3, andfour lesions completely obstructed. The deformation of bowel lumen on single side wasseen in 227 lesions and bilateral in 96 lesions. Mucosal changes showed as paralleltethered relief in 253 lesions, granular in 23 lesions, compression in 20 lesions anddiffused change in 62 lesions.In 48 cases rectum metastasis found on barium enema, 42 cases of rectum wallthickening were revealed on MSCT, in which 41 cases enhanced and 25 cases revealedas layering pattern. In 89 cases colon metastasis found on barium enema, 73 werefound with colon wall thickened, and in which 71 cases were enhanced and 31 caseshad layering pattern.Conclusion: The preferable sites of colorectal metastasis from gastric cancer aretransverse colon and rectum. Barium enema shows parallel tethered mucosal folds,granular appearances, compression and diffused invasion, and several changes maymixed, with the parallel tethered mucosal folds typical and the most common findings.Most lesions were progressed to typical change in the following examination, and partsof involved segments are elongated and especially the lesion of upper and middlerectum extended to lower part of rectum. From this study we considered that thoughthe pattern of colorectal metastasis from gastric cancer are always known as directinvasion and peritoneal seeding from primary tumor, we think the main route ofmalignant spread may be subperitoneal spread, and metastasis to the transverse colonfrom gastric tumor by the gastrocolic ligament may be one type of subperitonealspread.We studied the colorectal metastasis from gastric cancer mainly on the base ofthe imaging of barium enema. Although we studied the primary gastric lesions with pathological correlation, the limitation was lack of comprehensive pathologicalcorrelation in many metastasis lesions. So there are much unclear knowledge to beresearched about pathological features and mechanism of metastasis.Part twoThe radiological features of colorectal metastases from gastriccancer on MSCTPurpose: to analyze CT manifestations of colorectal metastasis from gastriccancer, and investigate the clinical and pathological characteristics and mechanism ofoccurrence and development of metastasis.Subject and methods: The history of one hundred and four patients who receivepreoperative routine radiological examination as suffering from gastric cancer or whobe examined because of being diagnosed recurrences or metastases of gastric cancerpostoperatively were analyzed. The imaging of MSCT were reviewedCT findings scanned at the same time when barium enema examined werereviewed by the consensus of two experienced radiologists. The findings wereevaluated on the following: the presence or absence of thickening at the site ofinvolvement, the pattern of enhancement, the thickening and nodule of omentum andperitoneum as well as ligament, and enhancement, the presence or absence of lymphnode swelling and mass in the abdominal cavity, ascites and distribution,hydronephrosis or hydroureter, liver or spleen metastasis, etc. For the cases whichreceived barium enema and CT more then one time, evaluate the progress of abovechanges.Results: In 48 cases rectum metastasis found on barium enema, 42 cases ofrectum wall thickening were revealed on MSCT, in which 41 cases enhanced and 25cases revealed as layering pattern. In 89 cases colon metastasis found on barium enema,73 were found with colon wall thickened, and in which 71 cases were enhanced and 31 cases had layering pattern.CT revealed ascites in 55 patients, with fluid in supramesocolic compartments in18 cases, inframesocolic in 4 cases, right and left paracolic gutters in 15 cases andpelvis in 45 cases. Pleural effusion was found in six patients. Omenta or mensentarywere remarkably thickened in three cases and nodule in 14 cases, hydronephrosis andhydroureter were found on CT in 27 patients, all of which were slightly dilated. Tumormass were found in two cases and hepatic metastasis in one patient.Forty-five patients were received MSCT scan in those patients, and 31 cases werefound the wall of involved bowel segment thicker then prior examination, and most oflesions developed as layered enhancement.Conclusion. CT findings at the time when lesions were found at barium enemamanifested as thickened bowel wall with typically concentric layering bowel wallthickening, as called it as target sign. Ascites, thickening of and nodule in omentum ormesentery, hydronephrosis and hydroureter were also features on CT images. Mass andhepatic metastasis are relatively rare. In the following up examination with bariumenema and CT, we found part of lesions may not be revealed out on MSCT at the slightchange on barium enema, but part of lesion may be more remarkable on CT thenbarium enema. Most lesions were progressed to typical change in the followingexamination, and parts of involved segments are elongated and especially the lesion ofupper and middle rectum extended to lower part of rectum. From this study weconsidered that though the pattem of colorectal metastasis from gastric cancer arealways known as direct invasion and peritoneal seeding from primary tumor, we thinkthe main route of malignant spread may be subperitoneal spread, and metastasis to thetransverse colon from gastric tumor by the gastrocolic ligament may be one type ofsubperitoneal spread. Part threeThe comparative study between radiological findings andpathology of primary gastric carcinoma in colorectal metastasis casesPurpose: to investigate the imaging characteriatics of primary gastric carcinomain colorectal cases compared with pathological findings, and study the correlationsbetween imaging features and histology of primary gastric carcinoma.Subject and methods: The radiological and pathological data of fifty six cases ofgastric cancinoma with complete records of operation pathology in one hundred andfour patients (same as part one) were collected. Radiological findings including the sizeand morphology of tumor were reviewed by the consensus of three experiencedradiologists. Morphology of tumor divided into six types as following: type 0(superficial type), type 1 (protruded type), type 2 (localized ulcerated type), type 3(invasive ulcerated type), type 4 (massive invasive type) and type 5 (unclassified).The histology of gastric cancer firstly divided into common type and special type,all cases in this study were common type, which further divided into papillaryadenocarcinoma (pap), well differentiated tubular adenocarcinoma (tub1), moderatelydifferentiated tubular adenocarcinoma (tub2), poorly differentiated adenocarcinoma (por),signet-ring cell carcinoma (sig) and mucinous adenocarcinoma (muc). The histologicalrecords such as the pattern of tumor infiltration, lymphatic infiltration, venousinfiltration and lymph nodes metastasis were reviewed. The correlation between theradiology and histology were statistically analyzed using spearman method.Results: the age of this 56 patients group range from 31 years old to 77 years old,among them, 43 cases in the range from 51 years old to 75 years old, accounting for76.8 percents. Radiologically, there were 2 cases of type 0, 1 case of type 1, 6 cases oftype 2, 22 cases of type 3 and 25 cases of type 4, with type 3 and type 4 accounting for83.9 percents. Histologically, there were 1 case of pap, 4 cases of tub1, 6 cases of tub237 cases of por, 6 cases of sig, and 2 cases of muc, with por for 66.1 percents. Therewere 40 cases of scirrhous type and 16 cases of intermediate type, without any case ofmedullary type in this 56 cases group. In the pattern of tumor infiltration, 43 cases manifested as typeγ, and 13 cases as typeβ, without any case of typeα. In thelymphatic and venous infiltration, 18 cases with no lymphatic Infiltration, 19 caseswith slight lymphatic infiltration, 11 cases with moderate and 8 cases with severeinfiltration were revealed, no venous infiltration were revealed in 40 cases, slightvenous infiltration in 14 cases and moderate venous infiltration in 2 cases, with nosevere venous infiltration case. Lymphatic nodes metastasis were not revealed in 15cases, the number of metastasis lymphatic nodes less than 5 were revealed in 14 cases,the number of metastasis lymphatic nodes between 6 and 10 were revealed in 8 cases,the number of metastasis lymphatic nodes more than 5 were revealed in 19 cases.Statistical analysis results shows that there were statistical significance incorrelation between the radiological morphology and the size of sub mucosa invasion,radiological morphology and the pattern of tumor infiltration, and minus correlationbetween radiological morphology and the lymphatic infiltration.Conclusion: The strong correlation is existed between radiological morphologyand histological features as the size of submucosal invasion and pattern of tumorinfiltration. In these cases of gastric carcinoma with colorectal metastasis, the tumorsmostly were type 4 and type 3, with massive submucosal invasion and massive tumorinfiltration.