BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of ...BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.CASE SUMMARY A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT(CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600 E mutation. The patients were alive and well during the follow-up period(range:0.6-5 yr).CONCLUSION There have been only a few previous reports of GISTs associated with NF-1.Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence,genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intraabdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities.Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.展开更多
More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but s...More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but second in mortality.More than half of the patients are in advanced stages at diagnosis.Treatment options are complex because of the heterogeneity of the patient population,including different molecular subtypes.Treatments have included conventional fluorouracil-based chemotherapy,targeted therapy,immunotherapy,etc.In recent years,with the development of genetic testing technology,more and more targeted drugs have been applied to the treatment of CRC,which has further prolonged the survival of metastatic CRC patients.展开更多
AIM: To clarify the biological role of stem cell factor (SCF)-mediated wild-type KIT receptor activation in gastrointestinal stromal tumor (GIST) growth. METHODS: The co-expression of wild-type KIT receptor and SCF wa...AIM: To clarify the biological role of stem cell factor (SCF)-mediated wild-type KIT receptor activation in gastrointestinal stromal tumor (GIST) growth. METHODS: The co-expression of wild-type KIT receptor and SCF was evaluated in 51 GIST samples using mutation analysis and immunohistochemistry, and the results were correlated with clinicopathological param- eters, including the mitotic count, proliferative index (Ki-67 immunohistochemical staining), mitotic index (phospho-histone H3 immunohistochemical staining) and apoptotic index (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling). Using primary cultured GIST cells, the effect of SCF-mediated wild-type KIT receptor activation was determined by western blotting, methyl thiazolyl tetrazolium (MTT), and apoptosis assays. RESULTS: We found that wild-type KIT receptor and SCF protein were expressed in 100% and 76.5% of the 51 GIST samples, respectively, and the co-expression of wild-type KIT receptor and SCF was associated with known indicators of poor prognosis, including larger tumor size (P = 0.0118), higher mitotic count (P = 0.0058), higher proliferative index (P = 0.0012), higher mitotic index (P = 0.0282), lower apoptosis index (P = 0.0484), and increased National Institutes of Health risk level (P = 0.0012). We also found that the introduction of exogenous SCF potently increased KIT kinase activity, stimulated cell proliferation (P < 0.01) and inhibited apoptosis (P < 0.01) induced by serum starvation, while a KIT immunoblocking antibody suppressed proliferation (P = 0.01) and promoted apoptosis (P < 0.01) in cultured GIST cells. CONCLUSION: SCF-mediated wild-type KIT receptor activation plays an important role in GIST cell growth. The inhibition of SCF-mediated wild-type KIT receptor activation may prove to be particularly important for GIST therapy.展开更多
Approximately 80%-95%of gastrointestinal stromal tumors(GISTs)show positive staining for KIT,while the other 5%-20%show negative staining.If the tumor is negative for KIT,but is positive for CD34,a histological diagno...Approximately 80%-95%of gastrointestinal stromal tumors(GISTs)show positive staining for KIT,while the other 5%-20%show negative staining.If the tumor is negative for KIT,but is positive for CD34,a histological diagnosis is possible.However,if the tumor is negative for KIT,CD34,S-100,and SMA,a definitive diagnosis is often challenging.Recently,Discovered on GIST-1(DOG1)has received considerable attention as a useful molecule for the diagnosis of GIST.DOG1,a membrane channel protein,is known to be overexpressed in GIST.Because the sensitivity and specificity of DOG1 are higher than those of KIT,positive staining for DOG1has been reported,even in KIT-negative GISTs.KITnegative GISTs most commonly arise in the stomach and are mainly characterized by epithelioid features histologically.We describe our experience with a rare case of a KIT-negative GIST of the stomach that was diagnosed by positive immunohistochemical staining for DOG1 in a patient who presented with severe anemia.Our findings suggest that immunohistochemical staining for DOG1,in addition to gene analysis,is useful for the diagnosis of KIT-negative tumors that are suspected to be GISTs.展开更多
目的联合检测EGFR野生型非小细胞肺癌（NSCLC）患者的ERCC1、RRM1、TYMS和TUBB3的mRNA表达水平差异,以探究4种基因的表达水平对化疗效果及预后的影响。方法将353例NSCLC患者的标本通过xTAG-液相芯片法筛选出EGFR野生型患者,采用实时荧...目的联合检测EGFR野生型非小细胞肺癌（NSCLC）患者的ERCC1、RRM1、TYMS和TUBB3的mRNA表达水平差异,以探究4种基因的表达水平对化疗效果及预后的影响。方法将353例NSCLC患者的标本通过xTAG-液相芯片法筛选出EGFR野生型患者,采用实时荧光定量PCR检测标本中4种基因的mRNA表达水平。EGFR野生型患者中4种基因均高表达的为高表达组,否则为低表达组,比较两组患者接受化疗后的中位无进展生存期及中位总生存期。结果遴选出EGFR野生型NSCLC患者227例,除吸烟与不吸烟者外,其他不同特征型患者之间4种基因mRNA表达水平之间差异无统计学意义（P〉0.05）。野生型高表达组有27例,野生型低表达组有53例,两组患者客观缓解率（ORR）（14.8%vs 41.5%,P〈0.05）、疾病控制率（DCR）（40.7%vs 81.1%,P〈0.05）、中位无进展生存期（月）（3.3 vs 4.9,P=0.001）与中位总生存期（月）（7.1 vs 8.1,P=0.048）间差异均有统计学意义。Cox多因素分析显示,4种基因高表达为EGFR野生型NSCLC患者化疗预后的独立危险因素（HR=1.92;95%CI：1.10~3.42）。结论 EGFR野生型NSCLC患者肿瘤组织的ERCC1、TYMS、TUBB3和RRM1 mRNA为高表达水平时,预示其对化疗药物具有耐药性。联合检测4种基因的表达有利于化疗方案的选择。展开更多
Although gastrointestinal stromal tumor(GIST) occurs generally in the digestive tract,omental GIST is very rare.We report the first case of an adult greater omental GIST with a new platelet-derived growth factor recep...Although gastrointestinal stromal tumor(GIST) occurs generally in the digestive tract,omental GIST is very rare.We report the first case of an adult greater omental GIST with a new platelet-derived growth factor receptor α gene(PDGFRA)-mutation with hemoperitoneum.A 43-year-old man was admitted to our hospital complaining of acute abdominal pain.Abdominal contrast-enhanced computed tomography revealed a huge mass in the right abdominal cavity,and a large accumulation of fluid in the pelvic cavity,suggesting hemoperitoneum.We diagnosed the rupture as an intra-abdominal tumor,and an emergency tumorectomy was performed with resection of the greater omentum.This tumor was located in the distal right side ofthe greater omentum,and showed no continuity with the gastric wall.The tumor occurred primarily in the greater omentum.The resected tumor was about 19 cm × 12 cm × 14 cm in diameter,and weighed 1529 g.Histologically,the tumor was composed of epithelioidshaped cells with high cellularity,and was positive for CD117 and CD34,and negative for S-100,α-smooth muscle actin.The mitosis was 6/50 under high power field.This case showed exon 18 mutation of PDGFRA with 846(Asp to Glu) substitution,848(Asn to Lys) substitution.This is the first report of this PDGFRA mutation in omental GIST,and this might play an important role in the tumorigenesis of this case.Based on these findings,the tumor was diagnosed as high risk GIST primarily occurring in the greater omentum.The patient was treated with imatinib at a dose of 400 mg/d as adjuvant chemotherapy,and has been followed up for 24 mo with no evidence of recurrence.展开更多
Gastrointestinal stromal tumors(GISTs) are the most common type of mesenchymal tumor of the gastrointestinal tract. The tumorigenesis of GISTs is driven by gain-of-function mutations in KIT or plateletderived growth f...Gastrointestinal stromal tumors(GISTs) are the most common type of mesenchymal tumor of the gastrointestinal tract. The tumorigenesis of GISTs is driven by gain-of-function mutations in KIT or plateletderived growth factor receptor α(PDGFRA),resultingin constitutive activation of the tyrosine kinase and its downstream signaling pathways. Oncogenic KIT or PDGFRA mutations are compelling therapeutic targets for the treatment of GISTs,and the KIT/PDGFRA inhibitor imatinib is the standard of care for patients with metastatic GISTs. However,most GIST patients develop clinical resistance to imatinib and other tyrosine kinase inhibitors. Five mechanisms of resistance have been characterized:(1) acquisition of a secondary point mutation in KIT or PDGFRA;(2) genomic amplification of KIT;(3) activation of an alternative receptor tyrosine kinase;(4) loss of KIT oncoprotein expression; and(5) wild-type GIST. Currently,sunitinib is used as a secondline treatment for patients after imatinib failure,and regorafenib has been approved for patients whose disease is progressing on both imatinib and sunitinib. Phase Ⅱ/Ⅲ trials are currently in progress to evaluate novel inhibitors and immunotherapies targeting KIT,its downstream effectors such as phosphatidylinositol 3-kinase,protein kinase B and mammalian target of rapamycin,heat shock protein 90,and histone deacetylase inhibitor. Other candidate targets have been identified,including ETV1,AXL,insulin-like growth factor 1 receptor,KRAS,FAS receptor,protein kinase c theta,ANO1(DOG1),CDC37,and aurora kinase A. These candidates warrant clinical evaluation as novel therapeutic targets in GIST.展开更多
Sendur et al pointed out the attention on the importance of mutational analysis for adjuvant treatment of gastrointestinal stromal tumor (GIST) in an article published in World Journal of Gastroenterology . In particu...Sendur et al pointed out the attention on the importance of mutational analysis for adjuvant treatment of gastrointestinal stromal tumor (GIST) in an article published in World Journal of Gastroenterology . In particular, they suggested that the optimal dose and duration of adjuvant therapy could be defined by the mutational status of the primary disease. This comment would underline the importance of centralised laboratories, given the increasingly important role of molecular analysis in the work-flow of all GIST, and the need of retrospective analyses for subgroups population stratified for the mutational status from the available studies in the adjuvant setting, in order to define the role of mutational analysis in choosing the optimal dose and duration of adjuvant therapy.展开更多
Gastrointestinal stromal tumors(GISTs)represent a malignant gastrointestinal tumor of neurofibromatosis type 1(NF1)Von Recklinghausen disease.In the current case,we report a 27-year-old woman with NF1,who presented wi...Gastrointestinal stromal tumors(GISTs)represent a malignant gastrointestinal tumor of neurofibromatosis type 1(NF1)Von Recklinghausen disease.In the current case,we report a 27-year-old woman with NF1,who presented with a lower abdominal mass,symptomatic anaemia,and significant weight loss.We employed multiple approaches to assess the tumor behavior,including computed tomography(CT)scan,surgical tumor resection,histological and immunohistochemical analysis and gene sequencing.Additionally,the patient was given Imatinib mesylate(Gleevec)as adjuvant therapy.CT scan delineated a large thick wall cavity lesion connecting to the small bowel segment.Resection of the tumor yielded a mass of 17 cm×13 cm with achievement of safety margins.The diagnosis was GIST,confirmed by immunohistochemical expression of CD117,CD34,and Bcl-2.Sequencing revealed no mutations in either KIT or platelet-derived growth factor receptor-alpha,genes which are mutated in over 85%of sporadic GIST cases.Further,there was no evidence of recurrence,metastasis or metachronous GIST for over three years in our patient.From our analyses,we believe selective genotyping is advisable for high risk patients to predict potential tumor behavior.展开更多
基金Supported by National Natural Science Foundation of China,No.81601692Program of Liaoning Province Department of Education,No.LK2016002
文摘BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.CASE SUMMARY A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT(CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600 E mutation. The patients were alive and well during the follow-up period(range:0.6-5 yr).CONCLUSION There have been only a few previous reports of GISTs associated with NF-1.Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence,genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intraabdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities.Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.
文摘More than 1.9 million new colorectal cancer(CRC)cases and 935000 deaths were estimated to occur worldwide in 2020,representing about one in ten cancer cases and deaths.Overall,colorectal ranks third in incidence,but second in mortality.More than half of the patients are in advanced stages at diagnosis.Treatment options are complex because of the heterogeneity of the patient population,including different molecular subtypes.Treatments have included conventional fluorouracil-based chemotherapy,targeted therapy,immunotherapy,etc.In recent years,with the development of genetic testing technology,more and more targeted drugs have been applied to the treatment of CRC,which has further prolonged the survival of metastatic CRC patients.
基金Supported by The National Natural Science Foundation of China, No.30700809 and No.30972876
文摘AIM: To clarify the biological role of stem cell factor (SCF)-mediated wild-type KIT receptor activation in gastrointestinal stromal tumor (GIST) growth. METHODS: The co-expression of wild-type KIT receptor and SCF was evaluated in 51 GIST samples using mutation analysis and immunohistochemistry, and the results were correlated with clinicopathological param- eters, including the mitotic count, proliferative index (Ki-67 immunohistochemical staining), mitotic index (phospho-histone H3 immunohistochemical staining) and apoptotic index (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling). Using primary cultured GIST cells, the effect of SCF-mediated wild-type KIT receptor activation was determined by western blotting, methyl thiazolyl tetrazolium (MTT), and apoptosis assays. RESULTS: We found that wild-type KIT receptor and SCF protein were expressed in 100% and 76.5% of the 51 GIST samples, respectively, and the co-expression of wild-type KIT receptor and SCF was associated with known indicators of poor prognosis, including larger tumor size (P = 0.0118), higher mitotic count (P = 0.0058), higher proliferative index (P = 0.0012), higher mitotic index (P = 0.0282), lower apoptosis index (P = 0.0484), and increased National Institutes of Health risk level (P = 0.0012). We also found that the introduction of exogenous SCF potently increased KIT kinase activity, stimulated cell proliferation (P < 0.01) and inhibited apoptosis (P < 0.01) induced by serum starvation, while a KIT immunoblocking antibody suppressed proliferation (P = 0.01) and promoted apoptosis (P < 0.01) in cultured GIST cells. CONCLUSION: SCF-mediated wild-type KIT receptor activation plays an important role in GIST cell growth. The inhibition of SCF-mediated wild-type KIT receptor activation may prove to be particularly important for GIST therapy.
文摘Approximately 80%-95%of gastrointestinal stromal tumors(GISTs)show positive staining for KIT,while the other 5%-20%show negative staining.If the tumor is negative for KIT,but is positive for CD34,a histological diagnosis is possible.However,if the tumor is negative for KIT,CD34,S-100,and SMA,a definitive diagnosis is often challenging.Recently,Discovered on GIST-1(DOG1)has received considerable attention as a useful molecule for the diagnosis of GIST.DOG1,a membrane channel protein,is known to be overexpressed in GIST.Because the sensitivity and specificity of DOG1 are higher than those of KIT,positive staining for DOG1has been reported,even in KIT-negative GISTs.KITnegative GISTs most commonly arise in the stomach and are mainly characterized by epithelioid features histologically.We describe our experience with a rare case of a KIT-negative GIST of the stomach that was diagnosed by positive immunohistochemical staining for DOG1 in a patient who presented with severe anemia.Our findings suggest that immunohistochemical staining for DOG1,in addition to gene analysis,is useful for the diagnosis of KIT-negative tumors that are suspected to be GISTs.
文摘目的联合检测EGFR野生型非小细胞肺癌（NSCLC）患者的ERCC1、RRM1、TYMS和TUBB3的mRNA表达水平差异,以探究4种基因的表达水平对化疗效果及预后的影响。方法将353例NSCLC患者的标本通过xTAG-液相芯片法筛选出EGFR野生型患者,采用实时荧光定量PCR检测标本中4种基因的mRNA表达水平。EGFR野生型患者中4种基因均高表达的为高表达组,否则为低表达组,比较两组患者接受化疗后的中位无进展生存期及中位总生存期。结果遴选出EGFR野生型NSCLC患者227例,除吸烟与不吸烟者外,其他不同特征型患者之间4种基因mRNA表达水平之间差异无统计学意义（P〉0.05）。野生型高表达组有27例,野生型低表达组有53例,两组患者客观缓解率（ORR）（14.8%vs 41.5%,P〈0.05）、疾病控制率（DCR）（40.7%vs 81.1%,P〈0.05）、中位无进展生存期（月）（3.3 vs 4.9,P=0.001）与中位总生存期（月）（7.1 vs 8.1,P=0.048）间差异均有统计学意义。Cox多因素分析显示,4种基因高表达为EGFR野生型NSCLC患者化疗预后的独立危险因素（HR=1.92;95%CI：1.10~3.42）。结论 EGFR野生型NSCLC患者肿瘤组织的ERCC1、TYMS、TUBB3和RRM1 mRNA为高表达水平时,预示其对化疗药物具有耐药性。联合检测4种基因的表达有利于化疗方案的选择。
文摘Although gastrointestinal stromal tumor(GIST) occurs generally in the digestive tract,omental GIST is very rare.We report the first case of an adult greater omental GIST with a new platelet-derived growth factor receptor α gene(PDGFRA)-mutation with hemoperitoneum.A 43-year-old man was admitted to our hospital complaining of acute abdominal pain.Abdominal contrast-enhanced computed tomography revealed a huge mass in the right abdominal cavity,and a large accumulation of fluid in the pelvic cavity,suggesting hemoperitoneum.We diagnosed the rupture as an intra-abdominal tumor,and an emergency tumorectomy was performed with resection of the greater omentum.This tumor was located in the distal right side ofthe greater omentum,and showed no continuity with the gastric wall.The tumor occurred primarily in the greater omentum.The resected tumor was about 19 cm × 12 cm × 14 cm in diameter,and weighed 1529 g.Histologically,the tumor was composed of epithelioidshaped cells with high cellularity,and was positive for CD117 and CD34,and negative for S-100,α-smooth muscle actin.The mitosis was 6/50 under high power field.This case showed exon 18 mutation of PDGFRA with 846(Asp to Glu) substitution,848(Asn to Lys) substitution.This is the first report of this PDGFRA mutation in omental GIST,and this might play an important role in the tumorigenesis of this case.Based on these findings,the tumor was diagnosed as high risk GIST primarily occurring in the greater omentum.The patient was treated with imatinib at a dose of 400 mg/d as adjuvant chemotherapy,and has been followed up for 24 mo with no evidence of recurrence.
基金Supported by The Special Project of Zhejiang Province,No.2012C03007-4Zhejiang Public Technology Research Program,No.2014C33234Zhejiang Provincial Top Key Discipline of Biology,and Science Foundation of Zhejiang Sci-Tech University,No.14042107-Y
文摘Gastrointestinal stromal tumors(GISTs) are the most common type of mesenchymal tumor of the gastrointestinal tract. The tumorigenesis of GISTs is driven by gain-of-function mutations in KIT or plateletderived growth factor receptor α(PDGFRA),resultingin constitutive activation of the tyrosine kinase and its downstream signaling pathways. Oncogenic KIT or PDGFRA mutations are compelling therapeutic targets for the treatment of GISTs,and the KIT/PDGFRA inhibitor imatinib is the standard of care for patients with metastatic GISTs. However,most GIST patients develop clinical resistance to imatinib and other tyrosine kinase inhibitors. Five mechanisms of resistance have been characterized:(1) acquisition of a secondary point mutation in KIT or PDGFRA;(2) genomic amplification of KIT;(3) activation of an alternative receptor tyrosine kinase;(4) loss of KIT oncoprotein expression; and(5) wild-type GIST. Currently,sunitinib is used as a secondline treatment for patients after imatinib failure,and regorafenib has been approved for patients whose disease is progressing on both imatinib and sunitinib. Phase Ⅱ/Ⅲ trials are currently in progress to evaluate novel inhibitors and immunotherapies targeting KIT,its downstream effectors such as phosphatidylinositol 3-kinase,protein kinase B and mammalian target of rapamycin,heat shock protein 90,and histone deacetylase inhibitor. Other candidate targets have been identified,including ETV1,AXL,insulin-like growth factor 1 receptor,KRAS,FAS receptor,protein kinase c theta,ANO1(DOG1),CDC37,and aurora kinase A. These candidates warrant clinical evaluation as novel therapeutic targets in GIST.
文摘Sendur et al pointed out the attention on the importance of mutational analysis for adjuvant treatment of gastrointestinal stromal tumor (GIST) in an article published in World Journal of Gastroenterology . In particular, they suggested that the optimal dose and duration of adjuvant therapy could be defined by the mutational status of the primary disease. This comment would underline the importance of centralised laboratories, given the increasingly important role of molecular analysis in the work-flow of all GIST, and the need of retrospective analyses for subgroups population stratified for the mutational status from the available studies in the adjuvant setting, in order to define the role of mutational analysis in choosing the optimal dose and duration of adjuvant therapy.
文摘Gastrointestinal stromal tumors(GISTs)represent a malignant gastrointestinal tumor of neurofibromatosis type 1(NF1)Von Recklinghausen disease.In the current case,we report a 27-year-old woman with NF1,who presented with a lower abdominal mass,symptomatic anaemia,and significant weight loss.We employed multiple approaches to assess the tumor behavior,including computed tomography(CT)scan,surgical tumor resection,histological and immunohistochemical analysis and gene sequencing.Additionally,the patient was given Imatinib mesylate(Gleevec)as adjuvant therapy.CT scan delineated a large thick wall cavity lesion connecting to the small bowel segment.Resection of the tumor yielded a mass of 17 cm×13 cm with achievement of safety margins.The diagnosis was GIST,confirmed by immunohistochemical expression of CD117,CD34,and Bcl-2.Sequencing revealed no mutations in either KIT or platelet-derived growth factor receptor-alpha,genes which are mutated in over 85%of sporadic GIST cases.Further,there was no evidence of recurrence,metastasis or metachronous GIST for over three years in our patient.From our analyses,we believe selective genotyping is advisable for high risk patients to predict potential tumor behavior.
