Prognostic factors associated with gastrointestinal dysfunction after gastrointestinal tumor surgery:A meta-analysis

BACKGROUND Explore the risk factors of gastrointestinal dysfunction after gastrointestinal tumor surgery and to provide evidence for the prevention and intervention of gastrointestinal dysfunction in patients with gastrointestinal tumor surgery.AIM To investigate the potential risk factors for gastrointestinal dysfunction following gastrointestinal tumor surgery and to present information supporting the prevention and management of gastrointestinal dysfunction in surgery patients.METHODS Systematically searched the relevant literature from PubMed,Web of Science,Cochrane Library,Embase,CNKI,China Biomedical Database,Wanfang Database,and Weipu Chinese Journal Database self-established until October 1,2022.Review Manager 5.3 software was used for meta-analysis after two researchers independently screened literature,extracted data,and evaluated the risk of bias in the included studies.RESULTS A total of 23 pieces of literature were included,the quality of which was medium or above,and the total sample size was 43878.The results of meta-analysis showed that the patients were male(OR=1.58,95%CI:1.25-2.01,P=0.002)and≥60 years old(OR=2.60,95%CI:1.76-2.87,P<0.001),physical index≥25.3 kg/m2(OR=1.6,95%CI:1.00-1.12,P=0.040),smoking history(OR=1.89,95%CI:1.31-2.73,P<0.001),chronic obstructive pulmonary disease(OR=1.49,95%CI:1.22-1.83,P<0.001),enterostomy(OR=1.47,95%CI:1.26-1.70,P<0.001),history of abdominal surgery(OR=2.90,95%CI:1.67-5.03,P<0.001),surgical site(OR=1.2,95%CI:1.40-2.62,P<0.001),operation method(OR=1.68,95%CI:1.08-2.62,P=0.020),operation duration(OR=2.65,95%CI:1.92-3.67,P<0.001),abdominal adhesion grade(OR=2.52,95%CI:1.90-3.56,P<0.001),postoperative opioid history(OR=5.35,95%CI:3.29-8.71,P<0.001),tumor TNM staging(OR=2.58,95%CI:1.84-3.62,P<0.001),postoperative blood transfusion(OR=2.92,95%CI:0.88-9.73,P=0.010)is a risk factor for postoperative gastrointestinal dysfunction in patients with gastrointestinal tumors.CONCLUSION There are many factors affecting gastrointestinal dysfunction in gastrointestinal patients after surgery.Clinical staff should identify relevant risk factors early and implement targeted intervention measures on the basis of personalized assessment to improve the clinical prognosis of patients.

Surgical aspects of small intestinal neuroendocrine tumors

Small intestinal neuroendocrine tumors(NETs)are a heterogeneous group of epithelial tumors with a predominant neuroendocrine differentiation.Although NETs are usually considered rare neoplasms,small intestinal NETs are the most common primary malignancy of the small bowel,with an increasing prevalence worldwide during the course of the past few decades.The indolent nature of these tumors often leads to a delayed diagnosis,resulting in over one-third of patients presenting with synchronous metastases.Primary tumor resection remains the only curative option for this type of tumor.In this review article,the various surgical aspects for the excision of small intestinal NETs are discussed.

Intestinal Flora and Gastrointestinal Tumors

Intestinal flora is a large and complex micro-ecosystem, and the growth and proliferation activities of different flora will have an important impact on the occurrence and development of gastric cancer and colorectal cancer as well as related treatment. This article reviews the latest research progress on the relationship between intestinal flora and gastric cancer and colorectal cancer.

Tumor necrosis factor-α mediates JNK activation response to intestinal ischemia-reperfusion injury

AIM:To investigate whether tumor necrosis factor-α(TNF-α)mediates ischemia-reperfusion(I/R)-induced intestinal mucosal injury through c-Jun N-terminal kinase(JNK)activation.METHODS:In this study,intestinal I/R was induced by 60-min occlusion of the superior mesenteric artery in rats followed by 60-min reperfusion,and the rats were pretreated with a TNF-α inhibitor,pentoxifylline,or the TNF-α antibody infliximab.After surgery,part of the intestine was collected for histological analysis.The mucosal layer was harvested for RNA and protein extraction,which were used for further real-time polymerase chain reaction,enzyme-linked immunosorbent assay and Western blotting analyses.The TNF-α expression,intestinal mucosal injury,cell apoptosis,activation of apoptotic protein and JNK signaling pathway were analyzed.RESULTS:I/R significantly enhanced expression of mucosal TNF-α at both the mRNA and protein levels,induced severe mucosal injury and cell apoptosis,activated caspase-9/caspase-3,and activated the JNK signaling pathway.Pretreatment with pentoxifylline markedly downregulated TNF-α at both the mRNA and protein levels,whereas infliximab pretreatment did not affect the expression of TNF-α induced by I/R.However,pretreatment with pentoxifylline or infliximab dramatically suppressed I/R-induced mucosal injury and cell apoptosis and significantly inhibited the activation of caspase-9/3 and JNK signaling.CONCLUSION:The results indicate there was a TNFα-mediated JNK activation response to intestinal I/R injury.

New progress in CT and MRI examination and diagnosis of small intestinal tumors

Precise examination and diagnosis of small intestinal tumors is difficult because of the curved course and overlapping canal of the small intestine. Traditional technology for intestinal canal examination and endoscopy cannot exhibit the intestinal wall and extra-luminal structure well. With the development and advancement of multi-slice spiral computed tomography and magnetic resonance imaging (MRI), computed tomography enteroclysis (CTE) and magnetic resonance enteroclysis (MRE) are widely used in the examination and diagnosis of small intestinal tumors. CTE and MRE, with three-dimensional imaging capabilities and excellent soft-tissue contrast, can analyze the abnormalities of peripheral intestinal structure as well as the tunica mucosa. In addition, these two technologies can clearly reveal the localization, appearance, degree of mesenteric infiltration and remote tumor metastasis, which increases our cognition of the imaging diagnosis for intestinal tumors. Here we review recent progress in imaging (CT and MRI) examination and diagnosis of small intestinal tumors.

Gastrointestinal neuroendocrine tumors in 2020

Gastrointestinal neuroendocrine tumors are rare slow-growing tumors with distinct histological,biological,and clinical characteristics that have increased in incidence and prevalence within the last few decades.They contain chromogranin A,synaptophysin and neuron-specific enolase which are necessary for making a diagnosis of neuroendocrine tumor.Ki-67 index and mitotic index correlate with cellular proliferation.Serum chromogranin A is the most commonly used biomarker to assess the bulk of disease and monitor treatment and is raised in both functioning and non-functioning neuroendocrine tumors.Most of the gastrointestinal neuroendocrine tumors are non-functional.World Health Organization updated the classification of neuroendocrine tumors in 2017 and renamed mixed adenoneuroendocrine carcinoma into mixed neuroendocrine neoplasm.Gastric neuroendocrine tumors arise from enterochromaffin like cells.They are classified into 4 types.Only type I and type II are gastrin dependent.Small intestinal neuroendocrine tumor is the most common small bowel malignancy.More than two-third of them occur in the terminal ileum within 60 cm of ileocecal valve.Patients with small intestinal neuroendrocrine tumors frequently show clinical symptoms and develop distant metastases more often than those with neuroendocrine tumors of other organs.Duodenal and jejunoileal neuroendocrine tumors are distinct biologically and clinically.Carcinoid syndrome generally occurs when jejuno-ileal neuroendocrine tumors metastasize to the liver.Appendiceal neuroendocrine tumors are generally detected after appendectomy.Colonic neuroendocrine tumors generally present as a large tumor with local or distant metastasis at the time of diagnosis.Rectal neuroendocrine tumors are increasingly being diagnosed since the implementation of screening colonoscopy in 2000.Gastrointestinal neuroendocrine tumors are diagnosed and staged by endoscopy with biopsy,endoscopic ultrasound,serology of biomarkers,imaging studies and functional somatostatin scans.Various treatment options are available for curative and palliative treatment of gastrointestinal neuroendocrine tumors.

Malignant glomus tumor of the intestinal ileum with multiorgan metastases:A case report and review of literature

BACKGROUND Glomus tumors(GTs)are rare mesenchymal neoplastic lesions derived from cells of the glomus body.GTs rarely occurs in the visceral organs,where there may be few or no glomus bodies,and the majority of GTs are benign,rarely demonstrating aggressive or malignant behavior and histological features.CASE SUMMARY We report a patient with malignant GTs of the intestinal ileum with multiorgan metastases who was admitted due to moderate anemia.Capsule endoscopy revealed a bleeding mass in the intestinal ileum,and the patient underwent segmental ileal resection through laparoscopic surgery.The histopathological and immunohistochemical diagnoses were consistent with malignant GT.Longterm follow-up showed that the GT had metastasized to multiple organs such as the colon,brain,and possibly the lung.CONCLUSION This case was characterized by the highest degree of malignancy and by multiorgan metastases,and it was the first case of intestinal GT uncovered by capsule endoscopy.

Endoscopic characteristics of small intestinal malignant tumors observed by balloon-assisted enteroscopy

BACKGROUND Capsule endoscopy and balloon-assisted enteroscopy(BAE) enable visualization of rare small bowel conditions such as small intestinal malignant tumors.However,details of the endoscopic characteristics of small intestinal malignant tumors are still unknown.AIM To elucidate the endoscopic characteristics of small intestinal malignant tumors.METHODS From March 2005 to February 2017,1329 BAE procedures were performed at Keio University Hospital. Of these procedures,malignant tumors were classified into three groups,Group 1: epithelial tumors including primary small intestinal cancer,metastatic small intestinal cancer,and direct small intestinal invasion by an adjacent organ cancer; Group 2: small intestinal malignant lymphoma; and Group 3,small intestinal gastrointestinal stromal tumors. We systematically collected clinical and endoscopic data from patients' medical records to determine the endoscopic characteristics for each group.RESULTS The number of patients in each group was 16(Group 1),23(Group 2),and 6(Group 3),and the percentage of solitary tumors was 100%,43.5%,and 100%,respectively(P < 0.001). Patients' clinical background parameters including age,symptoms,and laboratory data were not significantly different between the groups. Seventy-five percent of epithelial tumors(Group 1) were located in the upper small intestine(duodenum and ileum),and approximately 70% of gastrointestinal stromal tumors(Group 3) were located in the jejunum. Solitary protruding or mass-type tumors were not seen in malignant lymphoma(Group2)(P < 0.001). Stenosis was seen more often in Group 1,(68.8%,27.3%,and 0%;Group 1,2,and 3,respectively; P = 0.004). Enlarged white villi inside and/or surrounding the tumor were seen in 12.5%,54.5%,and 0% in Group 1,2,and 3,respectively(P = 0.001).CONCLUSION The differential diagnosis of small intestinal malignant tumors could be tentatively made based on BAE findings.

Perforation of the colon by invading recurrent gastrointestinal stromal tumors during sunitinib treatment

The molecular targets of sunitinib are receptor tyrosine kinases (RTKs),and this drug has also been known to exert blocking effects on the activation of KIT,which is similar to the mechanism of action of imatinib. Moreover,sunitinib has an additional anti-angiogenic effect through its inhibition of the vascular endothelial growth factor receptor activation. We report here a 70-year-old patient diagnosed with a recurrent gastrointestinal stromal tumor (GIST),which invaded the transverse colon and led to a perforation during sunitinib treatment. A computed tomography scan and 3-dimensional reconstruction showed necrosis of the recurrent hepatic mass and perforation of the invaded transverse colon. After percutaneous drainage of the intraperitoneal abscess,antibiotic treatment and restricted diet,the condition of the patient improved. The present case is the first to report that sunitinib,which is administered to treat GIST resistant to imatinib,can cause unexpected colon perforation and subsequent peritonitis.

Neuroendocrine Tumor of Small Intestine, a Diagnostic Challenge

Incidence of neuroendocrine tumors (NET) has significantly increased in the past three decades. In the small intestine, NET are the most frequent tumors, even more frequent than adenocarcinomas. Due to atypical presentations and late symptoms, NET in the small intestine frequently represent a diagnostic challenge. It is important to take these tumors into consideration in differential diagnosis of gastrointestinal neoplasms. Surgeons, oncologists, endocrinologists, and gastroenterologists should understand the disease characteristics and management alternatives. This document aims to review the key points of NET and main diagnostic tools. We present the case of a 50-year-old male who presented lower gastrointestinal bleeding. Imaging and endoscopic studies showed no conclusive findings. A capsule endoscopy showed multiple ulcered lesions with neoplastic aspect in the distal jejune. Due to the multifocal nature of the lesions, clinicians suspected NET-associated digestive bleeding. The patient underwent exploratory laparoscopy with ileectomy and radical abdominal lymphadenectomy. Histopathologic examination confirmed the suspected diagnosis of NET. This case reflects the complexity of diagnostic approach and differential diagnoses for these tumors.

Tumor necrosis factor alpha increases intestinal permeability in mice with fulminant hepatic failure

AIM:To determine the effect of tumor necrosis factor alpha(TNF-α) on intestinal permeability(IP) in mice with fulminant hepatic failure(FHF),and the expression of tight junction proteins.METHODS:We selected D-lactate as an index of IP,induced FHF using D-galactosamine/lipopolysaccharide and D-galactosamine/TNF-α,assessed the results using an enzymatic-spectrophotometric method,transmission electron microscopy,immunohistochemistry,Western blotting and real-time quantitative polymerase chain reaction.The effect of the administration of antiTNF-α immunoglobulin G(IgG) antibody,before the administration of D-galactosamine/lipopolysaccharide,on TNF-α was also assessed.RESULTS:IP was significantly increased in the mouse model of FHF 6 h after injection(13.57 ± 1.70 mg/L,13.02 ± 1.97 mg/L vs 3.76 ± 0.67 mg/L,P = 0.001).Electron microscopic analysis revealed tight junction(TJ) disruptions,epithelial cell swelling,and atrophy of intestinal villi.Expression of occludin and claudin-1 mRNA was significantly decreased in both FHF models(occludin:0.57 ± 0.159 fold vs baseline,P = 0.000;claudin-1:0.3067 ± 0.1291 fold vs baseline,P = 0.003),as were the distribution density of proteins in the intestinal mucosa and the levels of occludin and claudin-1 protein(occludin:0.61 ± 0.0473 fold vs baseline,P = 0.000;claudin-1:0.6633 ± 0.0328 fold vs baseline,P = 0.000).Prophylactic treatment with antiTNF-α IgG antibody prevented changes in IP(4.50 ± 0.97 mg/L vs 3.76 ± 0.67 mg/L,P = 0.791),intestinal tissue ultrastructure,and the mRNA levels of occludin and claudin-1 expression(occludin:0.8865 ± 0.0274 fold vs baseline,P = 0.505;claudin-1:0.85 ± 0.1437 fold vs baseline,P = 0.1),and in the protein levels(occludin:0.9467 ± 0.0285 fold vs baseline,P > 0.05;claudin-1:0.9533 ± 0.0186 fold vs baseline,P = 0.148).CONCLUSION:Increased in IP stemmed from the downregulation of the TJ proteins occludin and claudin-1,and destruction of the TJ in the colon,which were induced by TNF-α in FHF mice.

Perforation of metastatic melanoma to the small bowel with simultaneous gastrointestinal stromal tumor

The gastrointestinal tract (GIT) is a common site of metastases for malignant melanoma. These metastatic tumors are often asymptomatic. We describe a case of a 58-year-old male who presented with a sudden onset of generalized abdominal pain. The patient's past medical history was significant for lentigo melanoma of the right cheek. Laparotomy was performed and two segments ofsmall bowel, one with a perforated tumor, the other with a non-perforated tumor, were removed. Histology and immunohistochemical staining revealed the perforated tumor to be a metastatic malignant melanoma and the non-perforated tumor was found to be a gastrointestinal stromal tumor (GIST). The patient was discharged 7 d postoperatively. To the best of our knowledge, this is the first reported case in the literature of a simultaneous metastatic malignant melanoma and a GIST. Surgical intervention is warranted in patients with symptomatic GIT metastases to improve the quality of life or in those patients with surgical emergencies.

Upfront surgery of small intestinal neuroendocrine tumors. Time to reconsider?

Small intestinal neuroendocrine tumors(SI-NETs) may demonstrate a widely variable clinical behavior but usually it is indolent. In cases with localized disease, locoregional resective surgery(LRS) is generally indicated with a curative intent. LRS of SI-NETs is also the recommended treatment when symptoms are present, regardless of the disease stage. Concerning asymptomatic patients with distant metastases, prophylactic LRS has been traditionally suggested to avoid possible future complications. Even the current European Neuroendocrine Tumor Society guidelines emphasize a possible effect of LRS in Stage IV SINETs with unresectable liver metastases. On the contrary, the 2017 National Comprehensive Cancer Network Guidelines on carcinoid tumors do not support the resection of a small, asymptomatic, relatively stable primary tumor in the presence of unresectable metastatic disease. Furthermore, a recent study revealed no survival advantage for asymptomatic patients with distant-stage disease who underwent upfront LRS. At the aforementioned paper, it was suggested that delayed surgery as needed was comparable with the upfront surgical approach in terms of postoperative morbidity and mortality, the length of the hospital stay and the rate of incisional hernia repairs but was associated with fewer reoperations for bowel obstruction. On the other hand, it is also important to note that some patients might benefit from a prophylactic surgical approach and our attention should focus on identifying this patient population.

Multidisciplinary team for the diagnosis and treatment of 2cases of primary intestinal yolk sac tumor

Extragonadal primary yolk sac tumor of the intestinal tract origin is exceedingly rare. Through a multiple disciplinary team, the diagnosis and treatment of primary intestinal yolk sac tumor were further defined. We report 2 such cases with detailed histologic and immunohistochemical analysis. The two patients were a 7-year-old girl and a 29-year-old woman. Both of them preoperatively had an elevated serum alpha fetoprotein(AFP) level(≥ 1,210 ng/mL). The tumors are located in the intestine and imaging examination indicated the rectum as the primary site. Grossly the mass was grey-white and crisp texture. Microscopic examination featured reticular, microcystic, macrocystic, papillary, solid, and some glandular patterns. Immunohistochemically,tumor cells of both cases were positive for SALL4, AFP, pan-cytokeratin(AE1/AE3), and glypican-3. Simultaneously, a stain for EMA, OCT4, CD30, HCG, vimentin and CK20 were negative in all 2 neoplasms. The features of morphology,immunohistochemistry, laboratory examinations and imaging studies consist of the diagnosis of primary yolk sac tumor of the intestine.

YTE-17 inhibits colonic carcinogenesis by resetting antitumor immune response via Wnt5a/JNK mediated metabolic signaling

The density and composition of lymphocytes infiltrating colon tumors serve as predictive factors for the clinical outcome of colon cancer.Our previous studies highlighted the potent anti-cancer properties of the principal compounds found in Garcinia yunnanensis(YTE-17),attributing these effects to the regu-lation of multiple signaling pathways.However,knowledge regarding the mechanism and effect of YTE-17 in the prevention of colorectal cancer is limited.In this study,we conducted isobaric tags for relative and absolute quantification(iTRAQ)analysis on intestinal epithelial cells(IECs)exposed YTE-17,both in vitro and in vivo,revealing a significant inhibition of the Wnt family member 5a(Wnt5a)/c-Jun N-terminal kinase(JNK)signaling pathway.Subsequently,we elucidated the influence and mechanism of YTE-17 on the tumor microenvironment(TME),specifically focusing on macrophage-mediated T helper 17(Th17)cell induction in a colitis-associated cancer(CAC)model with Wnt5a deletion.Additionally,we performed the single-cell RNA sequencing(scRNA-seq)on the colonic tissue from the Wnt5a-deleted CAC model to characterize the composition,lineage,and functional status of immune mesenchymal cells during different stages of colorectal cancer(CRC)progression.Remarkably,our findings demon-strate a significant reduction in M2 macrophage polarization and Th17 cell phenotype upon treatment with YTE-17,leading to the restoration of regulatory T(Treg)/Th17 cell balance in azoxymethane(AOM)/dextran sodium sulfate(DSS)model.Furthermore,we also confirmed that YTE-17 effectively inhibited the glycolysis of Th17 cells in both direct and indirect co-culture systems with M2 macrophages.Notably,our study shed light on potential mechanisms linking the non-canonical Wnt5a/JNK signaling pathway and well-established canonical b-catenin oncogenic pathway in vivo.Specifically,we proposed that Wnt5a/JNK signaling activity in IECs promotes the development of cancer stem cells with b-catenin activity within the TME,involving macrophages and T cells.In summary,our study undergoes the po-tential of YTE-17 as a preventive strategy against CRC development by addressing the imbalance with the immune microenvironment,thereby mitigating the risk of malignancies.

A Rare Cause of Pneumoperitoneum: Perforated Gastrointestinal Stromal Tumor (GIST)

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor and has a malignant potential. The clinical presentation with pneumoperitoneum and peritonitis is extremely rare. We report a case of a 40-year-old male presented with symptoms of acute abdomen. Radiological work-up confirmed pneumoperitoneum. Emergency laparatomy and complete resection were performed. The final diagnosis revealed perforated GIST originating from the jejunum. If an abdominal mass presents with pneumoperitoneum and peritonitis, jejunal GIST should be considered in diagnosis. A complete radical resection followed by postoperative adjuvant chemotheraphy with Imatinib is recommended.

Wandering small intestinal stromal tumor:A case report

BACKGROUND The occurrence of gastrointestinal stromal tumors(GISTs)in the small intestine is rare,and a case of wandering small intestinal stromal tumor has been rarely reported to date.Dissemination of this case can help inform future diagnosis and effective treatment.CASE SUMMARY A 68-year-old patient presented to us with tarry stools.Computed tomography showed a mobile tumor moving widely within the abdominal cavity.As the laboratory data showed a low range of red blood cells and an immediate surgery was not indicated,we performed digital subtraction angiography and embolization to achieve hemostasis.Surgical resection was performed after the patient’s condition improved.The tumor was successfully removed laparoscopically.Histological examination revealed submucosal GIST with infarction,which was of intermediate-risk,with mitotic count<1 per 10 high-power field.Immunohistochemical studies revealed the following:CD117+,Dog1+,CD34+,SMA+,S100-,CK-,Des-,SOX-11-,STAT6-,Ki67 Hotspots 10%+.The patient was ultimately diagnosed with wandering small intestinal stromal tumor.CONCLUSION When a highly vascularized tumor is clinically encountered in the small intestine,the possibility of stromal tumors should be considered.However,when the tumor cannot be visualized at its original location,the possibility of tumor migration is considered.

Clinical and ultrasound features of small intestinal stromal tumors in woman pelvic cavity

Objective： The purpose of this study was to search the ultrasound features of small intestinal stromal tumor （SIST） in women by reviewing their clinical data. Methods： The study group consisted of 18 female patients with pathologically proven SIST in our hospital from 2000 to 2009. Medical records were reviewed for clinical information such as manifestation, findings of ultrasonography and immunohistochemical phenotype. Results： The average age of 18 female patients with SIST was 55.2 years （ranged, 39-84 years）. Seventeen cases of them had abnormal hypogastric masses, no mass in one case. The shapes of masses were round or Iobulate beside tightly uterus or ovary. The echo of masses was low. It＇s borders were clear and sometimes irregular. The sizes of the masses varied from 6.89-193.05 cm3, the diameter ranged from 24 tom-110 ram, 85.3% of which 50 mm-110 mm. There were rare color flow signals under color Doppler velocity mode or color Doppler power mode. Exploratory laparotomy confirmed that 16 cases of the tumors originated from small intestine, and 2 cases from the ileocecat. The positive rate of the immunohistochemical phenotype of CDl17 was 88.2%, and CD34 was 76.5%. The examination of pathology confirmed that 16 cases were malignant and 2 cases borderline tumors. Eighteen cases underwent radical surgical resection. Conclusion： The characteristics of SISTs in women pelvic cavity are： age 〉 40 years, a mass （proven not from productive system by ultrasonography） in pelvic cavity, melena, positive findings in pathology and CD117/CD34, especially notice masses which diameter is more than 50 mm and possess potential malignant. Ultrasonography is a convenient and effective tool of screening SISTs.

A Case Report of MODY_(3)Combined with Intestinal Neuroendocrine Tumor

Maturity-onset diabetes of the young 3(MODY_(3))is an autosomal dominant monogenic diabetes mellitus characterized by defective p-cell function and non-insulin-dependent early-onset diabetes mellitus.The facts that patients with MODY_(3) are often misdiagnosed as type 1 and type 2 diabetes mellitus and genetic diagnosis is expensive,make its diagnosis very challenging.In this study,we reported a case of MODY_(3),which was verified to be caused by a mutation in hepatocyte nuclear factor 1αgene(c.598C>X p.Arg200Trp).In addition,the patient had a neuroendocrine tumor simultaneously,and a KMT2D gene mutation(c.5587C>G,p.Prol863Ala)might be associated with this leson.

GASTROINTESTINAL STROMAL TUMORS:IMAGING FINDINGS

Gastrointestinal stromal tumor(GIST)is a non-epithelial neoplasm arising from the wall of the gastrointestinal(GI)tract.It is most frequently found in the stomach(60%-70%),followed by the small intestine(20%-30%),the colorectum(10%),and the esophagus(<5%).Some GISTs occur in the omentum,mesentery and retroperitoneum.GIST arising in the retroperitoneum is extremely rare,and its radiological findings have not been well described.However GISTs account for 2%-3% of all gastric tumors.GISTs are one of the most common mesenchymal tumors of the gastrointestinal tract.GIST referred to in the older medical literature as leiomyomas,leiomyoblastomas,and leiomyosarcomas because they were believed to originate from the smooth muscle layers of the wall of the gastrointestinal tract.Recently,however,immunoreactivity for KIT(CD117,a tyrosine kinase growth factor receptor)has differentiated gastrointestinal stromal tumors from true leiomyomas,leiomyosarcomas,neurofibromas,and schwannomas.In this review,we summarize the imaging findings of gastrointestinal stromal tumors and to determine whether some imaging features are useful for predicting malignancy in these tumors.