BACKGROUND Mucinous adenocarcinoma of the colorectum is a rare histological subtype characterized by an abundant mucinous component.Mucinous tumors are frequently diagnosed at an advanced stage,which indicates an aggr...BACKGROUND Mucinous adenocarcinoma of the colorectum is a rare histological subtype characterized by an abundant mucinous component.Mucinous tumors are frequently diagnosed at an advanced stage,which indicates an aggressive subtype.However,few case reports have been published,and little information is available concerning genetic alterations in mucinous adenocarcinoma.CASE SUMMARY A 76-year-old man underwent en bloc endoscopic submucosal dissection(ESD)for the management of a type 0-Is+IIa lesion.Histological examination revealed an intramucosal mucinous adenocarcinoma with signet-ring cell carcinoma and well-to-moderately differentiated tubular adenocarcinoma.Three years after the ESD,local recurrence was detected by an endoscopic examination,revealing a new 0-Is+IIa lesion with a phenotype similar to the previously resected lesion.Re-ESD was chosen for the management of the recurrent tumor,and the histological examination showed positive tumor infiltration at the vertical margin.Additional surgical resection was performed for the curative treatment.Genetic analysis showed pathogenic alterations in RNF43 and TP53 in the adenoma and an additional SMAD4 alteration in the carcinoma.CONCLUSION This mucinous mucosal adenocarcinoma case was suggested to have an aggressive phenotype and a careful and close follow-up are required.展开更多
BACKGROUND Epstein-Barr virus(EBV)-associated carcinoma is a gastric cancer subtype with a morphology characterized by gastric carcinoma with lymphoid stroma(GCLS).Clinicopathological studies have indicated a better p...BACKGROUND Epstein-Barr virus(EBV)-associated carcinoma is a gastric cancer subtype with a morphology characterized by gastric carcinoma with lymphoid stroma(GCLS).Clinicopathological studies have indicated a better prognosis for GCLS than for common gastric carcinomas.Some previous cases of early gastric cancer associated with EBV had been diagnosed by endoscopic resection.CASE SUMMARY We present two GCLS cases subjected to endoscopic submucosal dissection(ESD)for a definitive diagnosis.A protruded gastric lesion was identified by routine endoscopic examination,but forceps biopsy showed no atypical cells before ESD.The resected specimen showed a poorly differentiated adenocarcinoma with lymphoid cells involving the mucosa and submucosa.The final diagnosis was submucosa-invasive poorly differentiated gastric adenocarcinoma.Accordingly,additional gastrectomy was recommended to obtain a complete cure.One patient underwent additional distal gastrectomy with lymph node dissection,but the other was refused because of cardiovascular complications.Both patients remained in remission for more than half a year.EBV positivity was determined by EBV-encoded RNA in situ hybridization.We also conducted a literature review of cases of early gastric cancer associated with EBV that had been diagnosed by ESD.CONCLUSION Submucosa-invasive GCLS could be dissected using ESD,and EBV positivity should be subsequently assessed to determine whether or not any additional curative surgery is required.Further prospective investigations on the prevalence of lymph node metastasis in EBV-associated carcinoma should be performed to expand the indications for endoscopic resection.展开更多
The fabrication of heterostructures of two-dimensional semiconductors with specific bandgaps is an important approach to realizing the full potential of these materials in electronic and optoelectronic devices. Severa...The fabrication of heterostructures of two-dimensional semiconductors with specific bandgaps is an important approach to realizing the full potential of these materials in electronic and optoelectronic devices. Several groups have recently reported the direct growth of lateral and vertical heterostructures based on monolayers of typical semiconducting transition metal dichalcogenides （TMDCs） such as WSe2, MoSe2, WS2, and MoS2. Here, we demonstrate the single-step direct growth of lateral and vertical heterostructures based on bandgap-tunable Mo1-xWxS2 alloy monolayers by the sulfurization of patterned thin films of WO3 and MoO3. These patterned films are capable of generating a wide variety of concentration gradients by the diffusion of transition metals during the crystal growth phase. Under high temperatures, this leads to the formation of monolayer crystals of Mo1-xWxS2 alloys with various compositions and bandgaps, depending on the positions of the crystals on the substrates. Heterostructures of these alloys are obtained through stepwise changes in the ratio of W/Mo within a single domain during low-temperature growth. The stabilization of the monolayer Mo1-xWxS2 alloys, which often degrade even under gentle conditions, was accomplished by coating the alloys with other monolayers. The present findings demonstrate an efficient means of both studying and optimizing the optical and electrical properties of TMDC-based heterostructures to allow use of the materials in future device applications.展开更多
文摘BACKGROUND Mucinous adenocarcinoma of the colorectum is a rare histological subtype characterized by an abundant mucinous component.Mucinous tumors are frequently diagnosed at an advanced stage,which indicates an aggressive subtype.However,few case reports have been published,and little information is available concerning genetic alterations in mucinous adenocarcinoma.CASE SUMMARY A 76-year-old man underwent en bloc endoscopic submucosal dissection(ESD)for the management of a type 0-Is+IIa lesion.Histological examination revealed an intramucosal mucinous adenocarcinoma with signet-ring cell carcinoma and well-to-moderately differentiated tubular adenocarcinoma.Three years after the ESD,local recurrence was detected by an endoscopic examination,revealing a new 0-Is+IIa lesion with a phenotype similar to the previously resected lesion.Re-ESD was chosen for the management of the recurrent tumor,and the histological examination showed positive tumor infiltration at the vertical margin.Additional surgical resection was performed for the curative treatment.Genetic analysis showed pathogenic alterations in RNF43 and TP53 in the adenoma and an additional SMAD4 alteration in the carcinoma.CONCLUSION This mucinous mucosal adenocarcinoma case was suggested to have an aggressive phenotype and a careful and close follow-up are required.
文摘BACKGROUND Epstein-Barr virus(EBV)-associated carcinoma is a gastric cancer subtype with a morphology characterized by gastric carcinoma with lymphoid stroma(GCLS).Clinicopathological studies have indicated a better prognosis for GCLS than for common gastric carcinomas.Some previous cases of early gastric cancer associated with EBV had been diagnosed by endoscopic resection.CASE SUMMARY We present two GCLS cases subjected to endoscopic submucosal dissection(ESD)for a definitive diagnosis.A protruded gastric lesion was identified by routine endoscopic examination,but forceps biopsy showed no atypical cells before ESD.The resected specimen showed a poorly differentiated adenocarcinoma with lymphoid cells involving the mucosa and submucosa.The final diagnosis was submucosa-invasive poorly differentiated gastric adenocarcinoma.Accordingly,additional gastrectomy was recommended to obtain a complete cure.One patient underwent additional distal gastrectomy with lymph node dissection,but the other was refused because of cardiovascular complications.Both patients remained in remission for more than half a year.EBV positivity was determined by EBV-encoded RNA in situ hybridization.We also conducted a literature review of cases of early gastric cancer associated with EBV that had been diagnosed by ESD.CONCLUSION Submucosa-invasive GCLS could be dissected using ESD,and EBV positivity should be subsequently assessed to determine whether or not any additional curative surgery is required.Further prospective investigations on the prevalence of lymph node metastasis in EBV-associated carcinoma should be performed to expand the indications for endoscopic resection.
文摘The fabrication of heterostructures of two-dimensional semiconductors with specific bandgaps is an important approach to realizing the full potential of these materials in electronic and optoelectronic devices. Several groups have recently reported the direct growth of lateral and vertical heterostructures based on monolayers of typical semiconducting transition metal dichalcogenides （TMDCs） such as WSe2, MoSe2, WS2, and MoS2. Here, we demonstrate the single-step direct growth of lateral and vertical heterostructures based on bandgap-tunable Mo1-xWxS2 alloy monolayers by the sulfurization of patterned thin films of WO3 and MoO3. These patterned films are capable of generating a wide variety of concentration gradients by the diffusion of transition metals during the crystal growth phase. Under high temperatures, this leads to the formation of monolayer crystals of Mo1-xWxS2 alloys with various compositions and bandgaps, depending on the positions of the crystals on the substrates. Heterostructures of these alloys are obtained through stepwise changes in the ratio of W/Mo within a single domain during low-temperature growth. The stabilization of the monolayer Mo1-xWxS2 alloys, which often degrade even under gentle conditions, was accomplished by coating the alloys with other monolayers. The present findings demonstrate an efficient means of both studying and optimizing the optical and electrical properties of TMDC-based heterostructures to allow use of the materials in future device applications.
