Intestinal tuberculosis with small bowel stricture and hemorrhage as the predominant manifestation: Three case reports

BACKGROUND Intestinal tuberculosis is a chronic disease caused by Mycobacterium tuberculosis that mainly affects the ileum and cecum.Small bowel tuberculosis,characterized by predominant involvement of the small intestine,is an extremely rare condition with highly atypical clinical presentations,making diagnosis even more challenging.CASE SUMMARY We report three cases of small intestinal tuberculosis,two of the patients pre-sented primarily with abdominal pain,and one presented with gastrointestinal bleeding.All patients underwent blood tests and imaging examinations.Small bowel endoscopy(SBE)revealed that the main lesions in these patients were in-testinal stenosis or gastrointestinal bleeding caused by small intestinal ulcers.One patient ultimately underwent surgical treatment.Following a complex diagnostic process and comprehensive analysis,all patients were confirmed to have small intestinal tuberculosis and received standard antituberculosis treatment,leading to an improvement in their condition.CONCLUSION Patients with SBTs present with nonspecific symptoms such as abdominal pain,weight loss,and occasional gastrointestinal bleeding.Accurate diagnosis requires a thorough evaluation of clinical symptoms and various tests to avoid misdiagno-sis and complications.

Massive bleeding in small intestinal mucosa-associated lymphoid tissue lymphoma associated with COVID-19 infection:a case report

The increased risk of mucosa-associated lymphoid tissue(MALT)lymphoma is closely associated with chronic antigenic stimulation,with infection being the most common cause of recurrence.Lesions are usually associated with the gastrointestinal tract,and the involvement of small intestinal is rare.Recent studies have established a close relationship between novel coronavirus 2019(COVID-19)and the occurrence and progression of various diseases.This article presents a rare case of a small intestinal MALT lymphoma.The patient was initially admitted with COVID-19 pneumonia and subsequently developed gastrointestinal bleeding during hospitalization.Medical and endoscopic treatments were ineffective,and an emergency exploratory laparotomy was performed.The affected segment of the small intestine was excised,and a pathological biopsy confirmed the diagnosis of MALT lymphoma.This case underscores the significance of raising clinical awareness of this condition among health care professionals.

Ability of lactulose breath test results to accurately identify colorectal polyps through the measurement of small intestine bacterial overgrowth

BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive and expensive test.Thus,there is a need for new methods of screening patients at high risk of developing polyps.AIM To identify a potential association between colorectal polyps and small intestine bacteria overgrowth(SIBO)or other relevant factors in a patient cohort with lactulose breath test(LBT)results.METHODS A total of 382 patients who had received an LBT were classified into polyp and non-polyp groups that were confirmed by colonoscopy and pathology.SIBO was diagnosed by measuring LBTderived hydrogen(H)and methane(M)levels according to 2017 North American Consensus recommendations.Logistic regression was used to assess the ability of LBT to predict colorectal polyps.Intestinal barrier function damage(IBFD)was determined by blood assays.RESULTS H and M levels revealed that the prevalence of SIBO was significantly higher in the polyp group than in the non-polyp group(41%vs 23%,P<0.01;71%vs 59%,P<0.05,respectively).Within 90 min of lactulose ingestion,the peak H values in the adenomatous and inflammatory/hyperplastic polyp patients were significantly higher than those in the non-polyp group(P<0.01,and P=0.03,respectively).In 227 patients with SIBO defined by combining H and M values,the rate of IBFD determined by blood lipopolysaccharide levels was significantly higher among patients with polyps than those without(15%vs 5%,P<0.05).In regression analysis with age and gender adjustment,colorectal polyps were most accurately predicted with models using M peak values or combined H and M values limited by North American Consensus recommendations for SIBO.These models had a sensitivity of≥0.67,a specificity of≥0.64,and an accuracy of≥0.66.CONCLUSION The current study made key associations among colorectal polyps,SIBO,and IBFD and demonstrated that LBT has moderate potential as an alternative noninvasive screening tool for colorectal polyps.

Evaluating the accuracy and reproducibility of ChatGPT-4 in answering patient questions related to small intestinal bacterial overgrowth

BACKGROUND Small intestinal bacterial overgrowth(SIBO)poses diagnostic and treatment challenges due to its complex management and evolving guidelines.Patients often seek online information related to their health,prompting interest in large language models,like GPT-4,as potential sources of patient education.AIM To investigate ChatGPT-4's accuracy and reproducibility in responding to patient questions related to SIBO.METHODS A total of 27 patient questions related to SIBO were curated from professional societies,Facebook groups,and Reddit threads.Each question was entered into GPT-4 twice on separate days to examine reproducibility of accuracy on separate occasions.GPT-4 generated responses were independently evaluated for accuracy and reproducibility by two motility fellowship-trained gastroenterologists.A third senior fellowship-trained gastroenterologist resolved disagreements.Accuracy of responses were graded using the scale:(1)Comprehensive;(2)Correct but inadequate;(3)Some correct and some incorrect;or(4)Completely incorrect.Two responses were generated for every question to evaluate reproducibility in accuracy.RESULTS In evaluating GPT-4's effectiveness at answering SIBO-related questions,it provided responses with correct information to 18/27(66.7%)of questions,with 16/27(59.3%)of responses graded as comprehensive and 2/27(7.4%)responses graded as correct but inadequate.The model provided responses with incorrect information to 9/27(33.3%)of questions,with 4/27(14.8%)of responses graded as completely incorrect and 5/27(18.5%)of responses graded as mixed correct and incorrect data.Accuracy varied by question category,with questions related to“basic knowledge”achieving the highest proportion of comprehensive responses(90%)and no incorrect responses.On the other hand,the“treatment”related questions yielded the lowest proportion of comprehensive responses(33.3%)and highest percent of completely incorrect responses(33.3%).A total of 77.8%of questions yielded reproducible responses.CONCLUSION Though GPT-4 shows promise as a supplementary tool for SIBO-related patient education,the model requires further refinement and validation in subsequent iterations prior to its integration into patient care.

Simultaneously metastatic cholangiocarcinoma and small intestine cancer from breast cancer misdiagnosed as primary cholangiocarcinoma:A case report

BACKGROUND Cholangiocarcinoma and small intestine cancer are common clinical malignancies,but metastatic cholangiocarcinoma and small intestine cancer are rare,especially simultaneous metastatic cholangiocarcinoma and small intestine cancer from breast cancer.Since the clinical presentation of metastatic cholangiocarcinoma and small intestine cancer does not differ from primary tumor,it may lead to misdiagnosis preoperatively.CASE SUMMARY A 66-year-old woman was admitted to our hospital for further treatment due to abdominal pain and jaundice.Abdominal magnetic resonance imaging and magnetic resonance cholangiopancreatography showed an occupying lesion of the bile duct,considering a high possibility of primary bile duct tumor.Therefore,we performed a radical bile duct cancer surgery and cholecystectomy,and multiple tumors in the small intestine were found and removed during the surgery process.Postoperative pathology showed metastatic bile duct cancer and small intestine cancer from tumors in other parts.The patient underwent a right total mastectomy and axillary lymph node dissection because of right breast cancer 2 years ago.Combining with the immunohistochemical results,the patient was finally diagnosed as metastatic cholangiocarcinoma and metastatic small intestine cancer from breast cancer.Postoperatively,the patient received four cycles of chemotherapy and targeted therapy with docetaxel,capecitabine and trastuzumab.Unfortunately,the patient eventually died from tumor progression,thoracoabdominal infection,and sepsis 5 mo after surgery.CONCLUSION Simultaneous metastatic cholangiocarcinoma and small intestine cancer from breast cancer are rare and the prognosis is extremely poor.Improving preoperative diagnostic accuracy is beneficial to avoid excessive surgical treatment.Treatment should be aimed at relieving biliary obstruction and abdominal pain,and then supplemented with chemotherapy and targeted therapy to control tumor progression and prolong the patient’s life.

Current opinion on the regulation of small intestinal magnesium absorption

Magnesium(Mg^(2+))has an important role in numerous biological functions,and Mg^(2+)deficiency is associated with several diseases.Therefore,adequate intestinal absorption of Mg^(2+)is vital for health.The small intestine was previously thought to absorb digested Mg^(2+)exclusively through an unregulated paracellular mechanism,which is responsible for approximately 90%of total Mg^(2+)absorption.Recent studies,however,have revealed that the duodenum,jejunum,and ileum absorb Mg^(2+)through both transcellular and paracellular routes.Several regulatory factors of small intestinal Mg^(2+)uptake also have been explored,e.g.,parathyroid hormone,fibroblast growth factor-23,apical acidity,proton pump inhibitor,and pH-sensing channel and receptors.The mechanistic factors underlying proton pump inhibitor suppression of small intestinal Mg^(2+),such as magnesiotropic protein dysfunction,higher mucosal bicarbonate secretion,Paneth cell dysfunction,and intestinal inflammation,are currently being explored.The potential role of small intestinal microbiomes in Mg^(2+)absorption has also been proposed.In this article,we reviewed the current knowledge on the mechanisms and regulatory factors of small intestinal Mg^(2+)absorption.

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.

What are the effects of proton pump inhibitors on the small intestine?

Generally, proton-pump inhibitors(PPIs) have great benefit for patients with acid related disease with less frequently occurring side effects. According to a recent report, PPIs provoke dysbiosis of the small intestinal bacterial flora, exacerbating nonsteroidal anti-inflammatory drug-induced small intestinal injury.Several meta-analyses and systematic reviews have reported that patients treated with PPIs, as well as post-gastrectomy patients, have a higher frequency of small intestinal bacterial overgrowth(SIBO) compared to patients who lack the aforementioned conditions.Furthermore, there is insufficient evidence that these conditions induce Clostridium difficile infection. At this time, PPI-induced dysbiosis is considered a type of SIBO. It now seems likely that intestinal bacterial flora influence many diseases, such as inflammatory bowel disease, diabetes mellitus, obesity, nonalcoholic fatty liver disease, and autoimmune diseases.When attempting to control intestinal bacterial flora with probiotics, prebiotics, and fecal microbiota transplantation, etc., the influence of acid suppression therapy, especially PPIs, should not be overlooked.

Morphological and molecular response of small intestine to lactulose and hydrogen-rich water in female piglets fed Fusarium mycotoxins contaminated diet

Background: Following the intake of Fusarium mycotoxin-contaminated feed,small intestines may be exposed to high levels of toxic substances that can potentially damage intestinal functions in livestock.It is well known that Fusarium mycotoxins will lead a breakdown of the normally impeccable epithelial barrier,resulting in the development of a "leaky" gut.H2 administration with different methods has been proved definitely potentials to prevent serious intestinal diseases.The goal of this study is to investigate the roles of lactulose(LAC) and hydrogenrich water(HRW) in preventing intestinal dysfunction in piglets fed Fusarium mycotoxin-contaminated feed.Methods: A total of 24 female piglets were evenly assigned to 4 groups: negative control(NC) group,mycotoxincontaminated(MC) feed group,MC feed with LAC treatment(MC + LAC),and MC feed with HRW treatment(MC +HRW),respectively.Piglets in the NC group were fed uncontaminated control diet,while remaining piglets were fed Fusarium mycotoxin-contaminated diet.For the NC and MC groups,10 mL/kg body weight(BW) of hydrogen-free water(HFW) was orally administrated to piglets twice daily;while in the MC + LAC and MC + HRW groups,piglets were treated with the same dose of LAC solution(500 mg/kg BW) and HRW twice daily,respectively.On d 25,serum was collected and used for biochemical analysis.Intestinal tissues were sampled for morphological examination as well as relative genes and protein expression analysis.Results: Our data showed that Fusarium mycotoxins induced higher serum diamine oxidase(DAO) activities(P < 0.05),D-lactic acid levels(P < 0.01),and endotoxin status(P < 0.01),lower villus height(P < 0.01) and ratio of villus height to crypt depth(P < 0.05) in small intestine,greater apoptosis index and higher mRNA expression related to tight junctions(P < 0.05).In addition,the distribution and down-regulation of claudin-3(CLDN3) protein in the small intestinal was also observed.As expected,oral administrations of HRW and LAC were found to remarkably provide beneficial effects against Fusarium mycotoxin-induced apoptosis and intestinal leaking.Moreover,either HRW or LAC treatments were also revealed to prevent abnormal intestinal morphological changes,disintegrate tight junctions,and restore the expression and distribution of CLDN3 protein in the small intestinal mucosal layer in female piglets that were fed Fusarium mycotoxins contaminated diet.Conclusions: Our data suggest that orally administrations of HRW and LAC result in less Fusarium mycotoxininduced apoptosis and leak in the small intestine.Either HRW or LAC treatments could prevent the abnormal changes of intestinal morphology and molecular response of tight junctions as well as restore the distribution and expression of CLDN3 protein of small intestinal mucosa layer in female piglets that were fed Fusarium mycotoxins contaminated diet.

Protective effects of Ligustrazine,Kakonein and Panax Notoginsenoside on the small intestine and immune organs of rats with severe acute pancreatitis

BACKGROUND:Severe acute pancreatitis (SAP) is characterized by fatal pathogenic conditions and a high mortality.It is important to study SAP complicated with multiple organ injury.In this study we compared the protective effects of three traditional Chinese medicines (Ligustrazine,Kakonein and Panax Notoginsenoside) on the small intestine and immune organs (thymus,spleen and lymph nodes) of rats with SAP and explored their mechanism of action.METHODS:One hundred forty-four rats with SAP were randomly divided into model control,Ligustrazine-treated,Kakonein-treated,and Panax Notoginsenoside-treated groups (n=36 per group).Another 36 normal rats comprised the sham-operated group.According to the different time points after operation,the experimental rats in each group were subdivided into 3-,6-and 12-hour subgroups (n=12).At various time points after operation,the mortality rate of rats and pathological changes in the small intestine and immune organs were recorded and the serum amylase levels were measured.RESULTS:Compared to the model control groups,the mortality rates in all treated groups declined and the pathological changes in the small intestine and immune tissues were relieved to different degrees.The serum amylase levels in the three treated groups were significantly lower than those in the model control group at 12 hours.The pathological severity scores for the small intestinal mucosa,thymus and spleen (at 3 and 12 hours) in the Ligustrazine-treated group,for the thymus (at 3 and 12 hours) and spleen (at 3 and 6 hours) in the Kakonein-treated group,and for the thymus (at 3 hours)and spleen (at 3 hours) in the Panax Notoginsenoside-treated group were significantly lower than those in the model control group.The pathological severity scores of the small intestinal mucosa (at 6 and 12 hours) and thymus (at 6 hours) in the Ligustrazine-treated group were significantly lower than those in the Kakonein-and Panax Notoginsenoside-treated groups.CONCLUSIONS:All the three traditional Chinese drugs significantly alleviated the pathological changes in the small intestine and immune organs of SAP rats.Ligustrazine was the most effective one among them.

Giant primary angiosarcoma of the small intestine showing severe sepsis

Primary malignant tumors of the small intestine are rare,comprising less than 2%of all gastrointestinal tumors.An 85-year-old woman was admitted with fever of 40℃ and marked abdominal distension.Her medical history was unremarkable,but blood examination showed elevated inflammatory markers.Abdominal computed tomography showed a giant tumor with central necrosis,extending from the epigastrium to the pelvic cavity.Giant gastrointestinal stromal tumor of the small intestine communicating with the gastrointestinal tract or with superimposed infection was suspected.Because no improvement occurred in response to antibiotics,surgery was performed.Laparotomy revealed giant hemorrhagic tumor adherent to the small intestine and occupying the peritoneal cavity.The giant tumor was a solid tumor weighing 3490 g,measuring24 cm×17.5 cm×18 cm and showing marked necrosis.Histologically,the tumor comprised spindle-shaped cells with anaplastic large nuclei.Immunohistochemical studies showed tumor cells positive for vimentin,CD31,and factorⅧ-related antigen,but negative for c-kit and CD34.Angiosarcoma was diagnosed.Although no postoperative complications occurred,the patient experienced enlargement of multiple metastatic tumors in the abdominal cavity and died 42 d postoperatively.The prognosis of small intestinal angiosarcoma is very poor,even after volume-reducing palliative surgery.

Multiple chronic non-specific ulcer of small intestine characterized by anemia and hypoalbuminemia

A female patient with anemia and hypoalbuminemia was admitted to our hospital due to an over 20-year history of recurrent dizziness,fatigue and ankle edema.She was diagnosed as multiple chronic nonspecific ulcer of the small intestine characterized by non-specific histology and persistent gastrointestinal bleeding.

Epidemiology of cancer of the small intestine

Cancer of the small intestine is very uncommon.There are 4 main histological subtypes:adenocarcinomas,carcinoid tumors,lymphoma and sarcoma.The incidence of small intestine cancer has increased over the past several decades with a four-fold increase for carcinoid tumors,less dramatic rises for adenocarcinoma and lymphoma and stable sarcoma rates.Very little is known about its etiology.An increased risk has been noted for individuals with Crohn's disease,celiac disease,adenoma,familial adenomatous polyposis and Peutz-Jeghers syndrome.Several behavioral risk factors including consumption of red or smoked meat,saturated fat,obesity and smoking have been suggested.The prognosis for carcinomas of the small intestine cancer is poor(5 years relative survival < 30%),better for lymphomas and sarcomas,and best for carcinoid tumors.There has been no signif icant change in longterm survival rates for any of the 4 histological subtypes.Currently,with the possible exceptions of obesity and cigarette smoking,there are no established modifiable risk factors which might provide the foundation for a prevention program aimed at reducing the incidence and mortality of cancers of the small intestine.More research with better quality and sufficient statistical power is needed to get better understanding of the etiology and biology of this cancer.In addition,more studies should be done to assess not only exposures of interest,but also host susceptibility.

Heterogeneity across the murine small and large intestine

The small and large intestine of the gastrointestinal tract(GIT) have evolved to have discrete functions with distinct anatomies and immune cell composition.The importance of these differences is underlined when considering that different pathogens have uniquely adapted to live in each region of the gut.Furthermore,different regions of the GIT are also associated with differences in susceptibility to diseases such as cancer and chronic inflammation.The large and small intestine,given their anatomical and functional differences,should be seen as two separate immunological sites.However,this distinction is often ignored with findings from one area of the GIT being inappropriately extrapolated to the other.Focussing largely on the murine small and large intestine,this review addresses the literature relating to the immunology and biology of the two sites,drawing comparisons between them and clarifying similarities and differences.We also highlight the gaps in our understanding and where further research is needed.

AN ANALYTICAL SOLUTION FOR THE MODEL OF DRUG DISTRIBUTION AND ABSORPTION IN SMALL INTESTINE

According to the physiological and anatomical characteristics of small intestine,neglecting the effect of its motility on the distribution and absorption of drug and nutrient,Y.Miyamoto et al.proposed a model of two-dimensional laminar flow in a circular porous tube with permeable wall and calculated the concentration profile of drugby numerical analysis.In this paper,we give a steady-state analytical solution of the above model including deactivationterm.The obtained results are in agreement with the results of their numerical analysis. Moreover the analytical solution presented in this paper reveals the relation among the physiological parameters of the model and describes the basic absorption rule of drug and nutrient through the intestinal wall and hence pro- vides a theoretical basis for determining the permeability and reflection coefficient through in situ experiments.

Squamous Cell Carcinoma of Small Intestine: a Case Report

NEOPLASMS derive from small intestine are rareand most cases are adenocarcinomas andcarcinoid.1 Squamous cell carcinoma of smallintestine is even rarer and only few casesreported in literature.1 In this article, we report a case of a68-year-old male who underwent a laparotomy due toperforation of the small intestine and was diagnosed withsquamous cell carcinoma of the small intestine.

Small intestinal angiosarcoma on clinical presentation, diagnosis, management and prognosis: A case report and review of the literature

BACKGROUND Angiosarcoma is a highly malignant soft-tissue sarcoma derived from vascular endothelial cells that mainly occurs in the skin and subcutaneous tissues.Smallintestinal angiosarcomas are rare,and the prognosis is poor.CASE SUMMARY We reported a case of primary multifocal ileal angiosarcoma and analyze previously reported cases to improve our understanding of small intestinal angiosarcoma.Small intestinal angiosarcoma is more common in elderly and male patients.Gastrointestinal bleeding,anemia,abdominal pain,weakness,and weight loss were the common symptoms.CD31,CD34,factor VIII-related antigen,ETS-related gene,friend leukemia integration 1,and von Willebrand factor are valuable immunohistochemical markers for the diagnosis of small-intestinal angiosarcoma.Small-intestinal angiosarcoma most commonly occurs in the jejunum,followed by the ileum and duodenum.Radiation and toxicant exposure are risk factors for angiosarcoma.After a definite diagnosis,the mean and median survival time was 8 mo and 3 mo,respectively.Kaplan-Meier survival analysis showed that age,infiltration depth,chemotherapy,and the number of small intestinal segments invaded by tumor lesions were prognostic factors for small intestinal angiosarcoma.Multivariate Cox regression analysis showed that chemotherapy and surgery significantly improved patient prognosis.CONCLUSION Angiosarcoma should be considered for unexplained melena and abdominal pain,especially in older men and patients with a history of radiation exposure.Prompt treatment,including surgery and adjuvant chemotherapy,is essential to prolonging patient survival.

The impact of synbiotic administration through in ovo technology on the microstructure of a broiler chicken small intestine tissue on the 1^(st) and 42^(nd) day of rearing

Background： Application the innovative method which is in ovo technology provides a means of modulating the immune system at early embryonic stages. The aim of study was to determine influence of the in ovo stimulation, on d12 of incubation, with synbiotics（synbiotic 1-L. salivarius IBB3154 ＋ Bi^2tos, Clasado Ltd. and the synbiotic 2-L. plantarum IBB3036 ＋ lupin RFOs） on the microstructure of duodenum, jejunum and ileum in the 1^（st） and 42^（nd）day of rearing.Results： On the 1^（st） day of chickens life, in the duodenum of both experimental groups（SYN1 and SYN2）, a significantly higher and wider intestinal vil i as wel as a significantly larger absorbent surface of these villi were found in comparison with the Control group（P ≤ 0.01）. On the 42^（nd）day of rearing the beneficial effect of synbiotic 1 was reflected by the numerical y higher vil i（no statistical differences） with a larger surface（P ≤ 0.01） in the duodenum in the SYN1 group compare to the Control group. In the jejunum on the 1^（st） day of life, in the SYN1 group, significantly higher vil i than in the Control group, with a simultaneous decrease in the depth of crypts（P ≤ 0.01）, and also the largest width of vil i and their absorbent area（P ≤ 0.01） in comparison to the other groups were found. On the 42^（nd）day of life, in the jejunum, an increase in the height of the vil i whilst reducing the crypt depth in the SYN2 group was found（P ≤ 0.01）. In turn, in the SYN1 group, there were significantly more neutral goblet cel s observed compared with the control group（P ≤ 0.05）. In the ileum of 1-day-old chickens, the widest vil i（P ≤ 0.05） and the deepest crypts（P ≤ 0.01） were found in the SYN2 group. In the same group, there was also the least amount of neutral goblet cel s in comparison to the other groups（P ≤ 0.05）.Conclusions： We observed that synbiotic 1 and 2 beneficial y affected the examined characteristics on the 1^（st） and 42^（nd） day of life. The obtained results al ow us to conclude that the use of synbiotics significantly affect gut structure which should contribute to improvement in nutrient absorption by the gut.

Internal frontier:The pathophysiology of the small intestine

Even though the small intestine occupies a major portion of the abdominal space and is essential for life,in most pathology textbooks any chapter on small intestinal diseases,especially in human beings,is typically shorter than those for other gastrointestinal organs.Clinical and experimental investigations of the small intestine in various clinical situations,such as nutrition management,obesity interventions,and emergency care,have elucidated several important biological problems associated with the small intestine,the last frontier of gastroenterology.In this issue,a review by Professor Basson and his team at Michigan State University sheds light on the changes in the human small intestine under various conditions based on their clinical and surgical experience.With the advent of recent innovations in enteroscopy,a form of endoscopy used to examine deep within the small intestine,the issue that they highlighted,i.e.,mucosal adaptation and atrophy of the human small intestine,has emerged as a major and manageable challenge for gastroenterologists in general,including the readers of the World Journal of Gastroenterology.

Mucinous phenotype and CD10 expression of primary adenocarcinoma of the small intestine

AIM:To clarify the correlation with phenotypic expression,clinicopathological features,genetic alteration and microsatellite-instability status in small intestinal adenocarcinoma(SIA).METHODS:The cases of 47 patients diagnosed with primary SIAs that were surgically resected at our institution in 1975-2005 were studied.We reviewed clinicopathological findings(age,gender,tumor size,gross appearance,histological morphologic type,invasion depth,lymphatic permeation,venous invasion,and lymph node metastasis),and the immunohistochemical expression of MUC5 AC,MUC6,MUC2,CD10,and mismatch-repair(MMR) proteins(MLH1 and MSH2).We analyzed KRAS and BRAF gene mutations,and the microsatellite instability(MSI) status.The immunohistochemical staining of CD10,MUC2,MUC5 AC and MUC6 was considered positive when distinct staining in > 5% of the adenocarcinoma cells was recorded.To evaluate of MMR protein expression,we used adjacent normal tissue including lymphoid follicles,inflammatory cells,and stromal cells as an internal positive control.Sections without nuclear staining in the tumor cells were considered to have lost the expression of the respective MMR protein.RESULTS:There were 29 males and 18 females patients(mean age 59.9 years,range:23-87 years).Tumors were located in the duodenum in 14 cases(30%),the jejunum in 21 cases(45%),and the ileumin 12 cases(25%).A phenotypic expression analysis revealed 20 MUC2-positive tumors(42.6%),11 MUC5AC-positive(23.4%),4 MUC6-positive(8.5%),and 7 CD10-positive(14.9%).The tumor sizes of the MUC2(+) tumors were significantly larger than those of the MUC2(-) tumors(mean,5.7 ± 1.4 cm vs 4.7 ± 2.1 cm,P < 0.05).All three tumors with adenomatous component were positive for MUC2(P < 0.05).Polypoid appearance was seen significantly more frequently in the CD10(+) group than in the CD10(-) group(P < 0.05).The tumor size was significantly larger in the CD10(+) group than in the CD10(-) group(mean,5.9 ± 1.4 cm vs 5.0 ± 2.1 cm,P < 0.05).Of 34 SIAs with successfully obtained MSI data,4 were MSI-high.Of the 4 SIAs positive for both MUC5 AC and MUC2,3 showed MSI-H(75%) and 3 were mucinous adenocarcinoma(75%).KRAS mutations were detected in 4 SIAs.SIAs had KRAS mutation expressed only MUC2,but were negative for MUC5 AC,MUC6 and CD10.CONCLUSION:These findings suggest that the phenotypic expression of SIAs is correlated with their biological behavior,genetic alteration,and MSI status.