BACKGROUND Since fat does not transmit electrical energy well,delayed perforation and postpolypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma.The endoscopic s...BACKGROUND Since fat does not transmit electrical energy well,delayed perforation and postpolypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma.The endoscopic submucosal dissection(ESD)technique concentrates electrical energy conducts to the submucosa,not the adipose tissue.This helps to minimize electrical thermal injury,especially in the case of large colonic lipomas.In rare cases,such as colonic lipomas accompanied by mucosal lesions,it is difficult for endoscopists to decide how to safely remove them.CASE SUMMARY A 78-year-old man underwent colonoscopy for colorectal cancer screening.During colonoscopy,a yellowish submucosal tumor with positive cushion sign was observed in the ascending colon measuring about 4.5 cm.A nodular mucosal lesion of about 2.5 cm was observed on the mucosal surface of the lipoma.The lipoma was so large that it occupied much of the inside of the colon,making it difficult to see the entire laterally spreading tumor(LST)at once.The LST was confined to the surface of the lipoma,which had a semipedunculated shape with a wide neck.The margin of the LST was not observed at the neck of the lipoma.ESD was performed and the colonic lipoma with the LST was successfully removed without complications.After 3 d of hospitalization,the patient was discharged without any symptoms.The final pathology report showed that the lesion consisted of submucosal lipoma and tubulovillous adenoma with lowgrade dysplasia.CONCLUSION ESD is effective and safe for treating a large colonic lipoma with an LST by minimizing electrical thermal injury.展开更多
AIM： To clarify differences in mucin phenotype, prolif- erative activity and oncogenetic alteration among sub- types of colorectal laterally spreading tumor （LST）. METHODS： LSTs, defined as superficial elevated le...AIM： To clarify differences in mucin phenotype, prolif- erative activity and oncogenetic alteration among sub- types of colorectal laterally spreading tumor （LST）. METHODS： LSTs, defined as superficial elevated lesions greater than 10 mm in diameter with a low vertical axis, were macroscopically classified into two subtypes： （1） a granular type （Gr-LST） composed of superficially spread- ing aggregates of nodules forming a fiat-based lesion with a granulonodular and uneven surface; and （2） a non-granular type （NGr-LST） with a flat smooth surface and an absence of granulonodular formation. A total of 69 LSTs, comprising 36 Gr-LSTs and 33 NGr-LSTs, were immunohistochemically stained with MUC2, MUC5AC, MUC6, CD10 （markers of gastrointestinal cell lineage）, p53, 13-catenin and Ki-67 antibodies, and examined for alteration in exon 1 of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog （KRAS） and exon 15 of v-raf murine sarcoma viral oncogene homologue B1 （BRAF） by poly- merase chain reaction followed by direct sequencing. RESULTS： Histologically, 15 Gr-LST samples were ad- enomas with low-grade dysplasia （LGD）, 12 were high- grade dysplasia （HGD） and 9 were adenocarcinomas invading the submucosa （INV）, while 12 NGr-LSTs demonstrated LGD, 14 HGD and 7 INV. In the proximal colon, MUC5AC expression was significantly higher in the Gr-type than the NGr-type. MUC6 was expressed only in NGr-LST. MUC2 or CD10 did not differ. P53 ex- pression demonstrated a significant stepwise increment in progression through LGD-HGD-INV with both types of LST. Nuclear β-catenin expression was significantly higher in the NGr-type. Ki-67 expression was signifi- cantly higher in the Gr-type in the lower one third zone of the tumor. In proximal, but not distal colon tumors, the incidence of KRAS provided mutation was signifi- cantly higher in the Gr-type harboring a specific muta- tional pattern （G12V）. BRAF mutations （V600E） were detected only in two Gr-LSTs. CONCLUSION： The two subtypes of LST, especially in the proximal colon, have differing phenotypes of gastrointestinal cell lineage, proliferation and activa- tion of Wnt/β-catenin or RAS/RAF/extracellular signal- regulated kinase signaling.展开更多
AIM: To prospectively investigate the detection rate of laterally spreading tumors (LSTs) of the colorectum by computed tomography (CT) colonography (CTC).
BACKGROUND Colorectal mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease,and only a few cases have been reported to date.It has no specific clinical presentations and shows various endoscopic appearance...BACKGROUND Colorectal mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease,and only a few cases have been reported to date.It has no specific clinical presentations and shows various endoscopic appearances.There is no uniform consensus on its treatment.With the advancement of endoscopic technology,endoscopic treatment has achieved better results in individual case reports of early-stage patients.CASE SUMMARY We report a case of rectal MALT in a 57-year-old Chinese man with no symptoms who received endoscopy as part of a routine physical examination,which incidentally found a 25 mm×20 mm,laterally spreading tumor(LST)-like elevated lesion in the rectum.Therefore,he was referred to our hospital for further endoscopic treatment.Complete and curable removal of the tumor was performed by endoscopic submucosal dissection.We observed enlarged and dilated branch-like vessels similar to those of gastric MALT lymphoma on magnifying endoscopy with narrow-band imaging.And immunopathological staining showed hyperplastic capillaries in the mucosa.Histopathological findings revealed diffusely hyperplastic lymphoid tissue in the lamina propria,with a visible lymphoid follicle structure surrounded by a large number of diffusely infiltrated lymphoid cells that had a relatively simple morphology and clear cytoplasm.In addition,immunohistochemical analysis suggested strongly positive expression for CD20 and Bcl-2.Gene rearrangement results showed positivity for IGH-A,IGH-C,IGK-B,and IGL.Taking all the above findings together,we arrived at a diagnosis of extranodal marginal zone B-cell lymphoma of MALT lymphoma. Positron emission tomography-computed tomographyexamination showed no other lesions involved. The patient will be followed byperiodic endoscopic observation.CONCLUSIONIn conclusion, we report a case of rectal MALT with an LST-like appearancetreated by endoscopic submucosal dissection. Further studies will be needed toexplore the clinical behavior, endoscopic appearance, and treatment of rectalMALT.展开更多
BACKGROUND Colorectal laterally spreading tumors(LSTs)with malignant potential require en bloc resection by endoscopic submucosal dissection(ESD),but lesions with deep submucosal invasion(SMI)are endoscopically unrese...BACKGROUND Colorectal laterally spreading tumors(LSTs)with malignant potential require en bloc resection by endoscopic submucosal dissection(ESD),but lesions with deep submucosal invasion(SMI)are endoscopically unresectable.AIM To investigate the factors associated with high-grade dysplasia(HGD)/carcinoma and deep SMI in colorectal LSTs.METHODS The endoscopic and histological results of consecutive patients who underwent ESD for colorectal LSTs in our hospital from June 2013 to March 2019 were retrospectively analyzed.The characteristics of LST subtypes were compared.Risk factors for HGD/carcinoma and deep SMI(invasion depth≥1000μm)were determined using multivariate logistic regression.RESULTS A total of 323 patients with 341 colorectal LSTs were enrolled.Among the four subtypes,non-granular pseudodepressed(NG-PD)LSTs(85.5%)had the highest rate of HGD/carcinoma,followed by the granular nodular mixed(G-NM)(77.0%),granular homogenous(29.5%),and non-granular flat elevated(24.2%)subtypes.Deep SMI occurred commonly in NG-PD LSTs(12.9%).In the adjusted multivariate analysis,NG-PD[odds ratio(OR=16.8,P<0.001)and G-NM(OR=7.8,P<0.001)subtypes],size≥2 cm(OR=2.2,P=0.005),and positive non-lifting sign(OR=3.3,P=0.024)were independently associated with HGD/carcinoma.The NG-PD subtype(OR=13.3,P<0.001)and rectosigmoid location(OR=8.7,P=0.007)were independent risk factors for deep SMI.CONCLUSION Because of their increased risk for malignancy,it is highly recommended that NG-PD and G-NM LSTs are removed en bloc through ESD.Given their substantial risk for deep SMI,surgery needs to be considered for NG-PD LSTs located in the rectosigmoid,especially those with positive nonlifting signs.展开更多
Due to the advent of the screening programs for colorectal cancer and the era of quality assurance colonoscopy the number the polyps that can be considered difficult,including large(>20 mm)laterally spreading tumor...Due to the advent of the screening programs for colorectal cancer and the era of quality assurance colonoscopy the number the polyps that can be considered difficult,including large(>20 mm)laterally spreading tumors(LSTs),has increased in the last decade.All LSTs should be assessed carefully,looking for suspicious areas of submucosal invasion(SMI),such as nodules or depressed areas,describing the morphology according to the Paris classification,the pit pattern,and vascular pattern.The simplest,most appropriate and safest endoscopic treatment with curative intent should be selected.For LST-granular homogeneous type,piecemeal endoscopic mucosal resection should be the first option due to its biological low risk of SMI.LST-nongranular pseudodepressed type has an increased risk of SMI,and en bloc resection should be mandatory.Underwater endoscopic mucosal resection is useful in situations where submucosal injection alters the operative field,e.g.,for the resection of scar lesions,with no lifting,adjacent tattoo,incomplete resection attempts,lesions into a colonic diverticulum,in ileocecal valve and lesions with intra-appendicular involvement.Endoscopic full thickness resection is very useful for the treatment of difficult to resect lesions of less than 20 up to 25 mm.Among the indications,we highlight the treatment of polyps with suspected malignancy because the acquired tissue allows an exact histologic risk stratification to assign patients individually to the best treatment and avoid surgery for low-risk lesions.Endoscopic submucosal dissection is the only endoscopic procedure that allows completes en bloc resection regardless of the size of the lesion.It should therefore be indicated in the treatment of lesions with risk of SMI.展开更多
Colorectal laterally spreading tumor (LST) is a flat protuberant lesion originating from the colorectal mucosa, which is mainly charactherized by lateral superficial diffusion, and rarely vertically invades the deep w...Colorectal laterally spreading tumor (LST) is a flat protuberant lesion originating from the colorectal mucosa, which is mainly charactherized by lateral superficial diffusion, and rarely vertically invades the deep wall of the intestine. LST is closely related to the occurrence and development of colorectal cancer, but its pathological morphology and molecular mechanism are different from those of general adenoma, and it has some particularity. At present, the related research on LST in China has just started, but we find that its incidence is not low. Therefore, the research progress of epidemiology, molecular biology as well as clinical diagnosis and treatment of this disease is reviewed.展开更多
文摘BACKGROUND Since fat does not transmit electrical energy well,delayed perforation and postpolypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma.The endoscopic submucosal dissection(ESD)technique concentrates electrical energy conducts to the submucosa,not the adipose tissue.This helps to minimize electrical thermal injury,especially in the case of large colonic lipomas.In rare cases,such as colonic lipomas accompanied by mucosal lesions,it is difficult for endoscopists to decide how to safely remove them.CASE SUMMARY A 78-year-old man underwent colonoscopy for colorectal cancer screening.During colonoscopy,a yellowish submucosal tumor with positive cushion sign was observed in the ascending colon measuring about 4.5 cm.A nodular mucosal lesion of about 2.5 cm was observed on the mucosal surface of the lipoma.The lipoma was so large that it occupied much of the inside of the colon,making it difficult to see the entire laterally spreading tumor(LST)at once.The LST was confined to the surface of the lipoma,which had a semipedunculated shape with a wide neck.The margin of the LST was not observed at the neck of the lipoma.ESD was performed and the colonic lipoma with the LST was successfully removed without complications.After 3 d of hospitalization,the patient was discharged without any symptoms.The final pathology report showed that the lesion consisted of submucosal lipoma and tubulovillous adenoma with lowgrade dysplasia.CONCLUSION ESD is effective and safe for treating a large colonic lipoma with an LST by minimizing electrical thermal injury.
基金Supported by A grant-in-aid for General Scientific Research from the Ministry of Education, Science, Sports and Culture to Hiroyuki Mitomi, No. 21590394to Tsuyoshi Saito, No. 23590434, To-kyo, Japan
文摘AIM： To clarify differences in mucin phenotype, prolif- erative activity and oncogenetic alteration among sub- types of colorectal laterally spreading tumor （LST）. METHODS： LSTs, defined as superficial elevated lesions greater than 10 mm in diameter with a low vertical axis, were macroscopically classified into two subtypes： （1） a granular type （Gr-LST） composed of superficially spread- ing aggregates of nodules forming a fiat-based lesion with a granulonodular and uneven surface; and （2） a non-granular type （NGr-LST） with a flat smooth surface and an absence of granulonodular formation. A total of 69 LSTs, comprising 36 Gr-LSTs and 33 NGr-LSTs, were immunohistochemically stained with MUC2, MUC5AC, MUC6, CD10 （markers of gastrointestinal cell lineage）, p53, 13-catenin and Ki-67 antibodies, and examined for alteration in exon 1 of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog （KRAS） and exon 15 of v-raf murine sarcoma viral oncogene homologue B1 （BRAF） by poly- merase chain reaction followed by direct sequencing. RESULTS： Histologically, 15 Gr-LST samples were ad- enomas with low-grade dysplasia （LGD）, 12 were high- grade dysplasia （HGD） and 9 were adenocarcinomas invading the submucosa （INV）, while 12 NGr-LSTs demonstrated LGD, 14 HGD and 7 INV. In the proximal colon, MUC5AC expression was significantly higher in the Gr-type than the NGr-type. MUC6 was expressed only in NGr-LST. MUC2 or CD10 did not differ. P53 ex- pression demonstrated a significant stepwise increment in progression through LGD-HGD-INV with both types of LST. Nuclear β-catenin expression was significantly higher in the NGr-type. Ki-67 expression was signifi- cantly higher in the Gr-type in the lower one third zone of the tumor. In proximal, but not distal colon tumors, the incidence of KRAS provided mutation was signifi- cantly higher in the Gr-type harboring a specific muta- tional pattern （G12V）. BRAF mutations （V600E） were detected only in two Gr-LSTs. CONCLUSION： The two subtypes of LST, especially in the proximal colon, have differing phenotypes of gastrointestinal cell lineage, proliferation and activa- tion of Wnt/β-catenin or RAS/RAF/extracellular signal- regulated kinase signaling.
文摘AIM: To prospectively investigate the detection rate of laterally spreading tumors (LSTs) of the colorectum by computed tomography (CT) colonography (CTC).
文摘BACKGROUND Colorectal mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease,and only a few cases have been reported to date.It has no specific clinical presentations and shows various endoscopic appearances.There is no uniform consensus on its treatment.With the advancement of endoscopic technology,endoscopic treatment has achieved better results in individual case reports of early-stage patients.CASE SUMMARY We report a case of rectal MALT in a 57-year-old Chinese man with no symptoms who received endoscopy as part of a routine physical examination,which incidentally found a 25 mm×20 mm,laterally spreading tumor(LST)-like elevated lesion in the rectum.Therefore,he was referred to our hospital for further endoscopic treatment.Complete and curable removal of the tumor was performed by endoscopic submucosal dissection.We observed enlarged and dilated branch-like vessels similar to those of gastric MALT lymphoma on magnifying endoscopy with narrow-band imaging.And immunopathological staining showed hyperplastic capillaries in the mucosa.Histopathological findings revealed diffusely hyperplastic lymphoid tissue in the lamina propria,with a visible lymphoid follicle structure surrounded by a large number of diffusely infiltrated lymphoid cells that had a relatively simple morphology and clear cytoplasm.In addition,immunohistochemical analysis suggested strongly positive expression for CD20 and Bcl-2.Gene rearrangement results showed positivity for IGH-A,IGH-C,IGK-B,and IGL.Taking all the above findings together,we arrived at a diagnosis of extranodal marginal zone B-cell lymphoma of MALT lymphoma. Positron emission tomography-computed tomographyexamination showed no other lesions involved. The patient will be followed byperiodic endoscopic observation.CONCLUSIONIn conclusion, we report a case of rectal MALT with an LST-like appearancetreated by endoscopic submucosal dissection. Further studies will be needed toexplore the clinical behavior, endoscopic appearance, and treatment of rectalMALT.
基金Supported by Beijing Nova Program,No.Z201100006820147Beijing Municipal Administration of Hospitals’Youth Program,No.QML20180102。
文摘BACKGROUND Colorectal laterally spreading tumors(LSTs)with malignant potential require en bloc resection by endoscopic submucosal dissection(ESD),but lesions with deep submucosal invasion(SMI)are endoscopically unresectable.AIM To investigate the factors associated with high-grade dysplasia(HGD)/carcinoma and deep SMI in colorectal LSTs.METHODS The endoscopic and histological results of consecutive patients who underwent ESD for colorectal LSTs in our hospital from June 2013 to March 2019 were retrospectively analyzed.The characteristics of LST subtypes were compared.Risk factors for HGD/carcinoma and deep SMI(invasion depth≥1000μm)were determined using multivariate logistic regression.RESULTS A total of 323 patients with 341 colorectal LSTs were enrolled.Among the four subtypes,non-granular pseudodepressed(NG-PD)LSTs(85.5%)had the highest rate of HGD/carcinoma,followed by the granular nodular mixed(G-NM)(77.0%),granular homogenous(29.5%),and non-granular flat elevated(24.2%)subtypes.Deep SMI occurred commonly in NG-PD LSTs(12.9%).In the adjusted multivariate analysis,NG-PD[odds ratio(OR=16.8,P<0.001)and G-NM(OR=7.8,P<0.001)subtypes],size≥2 cm(OR=2.2,P=0.005),and positive non-lifting sign(OR=3.3,P=0.024)were independently associated with HGD/carcinoma.The NG-PD subtype(OR=13.3,P<0.001)and rectosigmoid location(OR=8.7,P=0.007)were independent risk factors for deep SMI.CONCLUSION Because of their increased risk for malignancy,it is highly recommended that NG-PD and G-NM LSTs are removed en bloc through ESD.Given their substantial risk for deep SMI,surgery needs to be considered for NG-PD LSTs located in the rectosigmoid,especially those with positive nonlifting signs.
文摘Due to the advent of the screening programs for colorectal cancer and the era of quality assurance colonoscopy the number the polyps that can be considered difficult,including large(>20 mm)laterally spreading tumors(LSTs),has increased in the last decade.All LSTs should be assessed carefully,looking for suspicious areas of submucosal invasion(SMI),such as nodules or depressed areas,describing the morphology according to the Paris classification,the pit pattern,and vascular pattern.The simplest,most appropriate and safest endoscopic treatment with curative intent should be selected.For LST-granular homogeneous type,piecemeal endoscopic mucosal resection should be the first option due to its biological low risk of SMI.LST-nongranular pseudodepressed type has an increased risk of SMI,and en bloc resection should be mandatory.Underwater endoscopic mucosal resection is useful in situations where submucosal injection alters the operative field,e.g.,for the resection of scar lesions,with no lifting,adjacent tattoo,incomplete resection attempts,lesions into a colonic diverticulum,in ileocecal valve and lesions with intra-appendicular involvement.Endoscopic full thickness resection is very useful for the treatment of difficult to resect lesions of less than 20 up to 25 mm.Among the indications,we highlight the treatment of polyps with suspected malignancy because the acquired tissue allows an exact histologic risk stratification to assign patients individually to the best treatment and avoid surgery for low-risk lesions.Endoscopic submucosal dissection is the only endoscopic procedure that allows completes en bloc resection regardless of the size of the lesion.It should therefore be indicated in the treatment of lesions with risk of SMI.
文摘Colorectal laterally spreading tumor (LST) is a flat protuberant lesion originating from the colorectal mucosa, which is mainly charactherized by lateral superficial diffusion, and rarely vertically invades the deep wall of the intestine. LST is closely related to the occurrence and development of colorectal cancer, but its pathological morphology and molecular mechanism are different from those of general adenoma, and it has some particularity. At present, the related research on LST in China has just started, but we find that its incidence is not low. Therefore, the research progress of epidemiology, molecular biology as well as clinical diagnosis and treatment of this disease is reviewed.
