Clinical course of suspected small gastrointestinal stromal tumors in the stomach

BACKGROUND Gastric subepithelial lesions are frequently encountered during endoscopic examinations,and the majority of them are small and asymptomatic.Among these lesions,gastrointestinal stromal tumors(GISTs)are the major concern for patients and clinicians owing to their malignant potentials.Although previous guidelines suggested periodic surveillance for such small(≤20 mm)lesions,several patients and clinicians have still requested or prescribed repeated examinations or radical resection,posing extra medical burdens and risks.AIM To describe the clinical course of suspected small gastric GISTs and provide further evidence for surveillance strategy for tumor therapy.METHODS This single-center,retrospective study was conducted at West China Hospital,Sichuan University.Consecutive patients with suspected small gastric GISTs were reviewed from November 2004 to November 2018.GIST was suspected according to endoscopic ultrasonography features:hypoechoic lesions from muscularis propria or muscularis mucosa.Eligible patients with suspected small(≤20 mm)GISTs were included for analysis.Patients’demographic data,lesions’characteristics,and follow-up medical records were collected.RESULTS A total of 383 patients(male/female,121/262;mean age,54 years)with 410 suspected small gastric GISTs(1 lesion in 362 patients,2 lesions in 16,3 lesions in4,and 4 lesions in 1)were included for analysis.The most common location was gastric fundus(56.6%),followed by body(29.0%),cardia(12.2%),and antrum(2.2%).After a median follow-up of 28 mo(interquartile range,16-48;range,3-156),402 lesions(98.0%)showed no changes in size,and size of 8 lesions(2.0%)was increased(mean increment,10 mm).Of the 8 lesions with size increment,endoscopic or surgical resection was performed in 6 patients(5 GISTs and 1 leiomyoma).For other 2 remaining patients,unroofing biopsy or endoscopic ultrasound-guided fine-needle aspiration was carried out(2 GISTs),while no further change in size was noted over a period of 62-64 mo.CONCLUSION The majority of suspected small(≤20 mm)gastric GISTs had no size increment during follow-up.Regular endoscopic follow-up without pathological diagnosis may be highly helpful for such small gastric subepithelial lesions.

Endoscopic enucleation of gastrointestinal stromal tumors of the stomach: Report of five cases

Gastrointestinal stromal tumor (GIST) of the stomach was treated by endoscopic enucleation in five patients. They were three men and two woman, aged 36-56 years. Tumors located in the cardia were completely enucleated endoscopically without any serious complication. The largest diameter of removed tumors ranged from 1.2 to 2.5 cm. Histopathological diagnosis was GIST with low risk of malignancy (mitotic index < 5/50 high power field) in all cases. The patients were disease-free for 10.5-42.2 mo after endoscopic enucleation.

Efficacy and safety of endoscopic resection in treatment of small gastric stromal tumors: A state-of-the-art review

Gastrointestinal stromal tumors can occur in any part of the gastrointestinal tract,but gastric stromal tumors(GSTs)are the most common.All GSTs have the potential to become malignant,and these can be divided into four different grades by risk from low to high:Very low risk,low risk,medium risk,and high risk.Current guidelines all recommend early complete excision of GSTs larger than 2 cm in diameter.However,it is not clear whether small GSTs(sGSTs,i.e.,those smaller than 2 cm in diameter)should be treated as early as possible.The National Comprehensive Cancer Network recommends that endoscopic ultrasonographyguided(EUS-guided)fine-needle aspiration biopsy and imaging(computed tomography or magnetic-resonance imaging)be used to assess cancer risk for sGSTs detected by gastroscopy to determine treatment.When EUS indicates a higher risk of tumor,surgical resection is recommended.There are some questions on whether sGSTs also require early treatment.Many studies have shown that endoscopic treatment of GSTs with diameters of 2-5 cm is very effective.We here address whether endoscopic therapy is also suitable for sGSTs.In this paper,we try to explain three questions:(1)Does sGST require treatment?(2)Is digestive endoscopy a safe and effective means of treating sGST?and(3)When sGSTs are at different sites and depths,which endoscopic treatment method is more suitable?

Relationship between multi-slice computed tomography features and pathological risk stratification assessment in gastric gastrointestinal stromal tumors

BACKGROUND Computed tomography(CT)imaging features are associated with risk stratification of gastric gastrointestinal stromal tumors(GISTs).AIM To determine the multi-slice CT imaging features for predicting risk stratification in patients with primary gastric GISTs.METHODS The clinicopathological and CT imaging data for 147 patients with histologically confirmed primary gastric GISTs were retrospectively analyzed.All patients had received dynamic contrast-enhanced CT(CECT)followed by surgical resection.According to the modified National Institutes of Health criteria,147 lesions were classified into the low malignant potential group(very low and low risk;101 lesions)and high malignant potential group(medium and high-risk;46 lesions).The association between malignant potential and CT characteristic features(including tumor location,size,growth pattern,contour,ulceration,cystic degeneration or necrosis,calcification within the tumor,lymphadenopathy,enhancement patterns,unenhanced CT and CECT attenuation value,and enhancement degree)was analyzed using univariate analysis.Multivariate logistic regression analysis was performed to identify significant predictors of high malignant potential.The receiver operating curve(ROC)was used to evaluate the predictive value of tumor size and the multinomial logistic regression model for risk classification.RESULTS There were 46 patients with high malignant potential and 101 with low-malignant potential gastric GISTs.Univariate analysis showed no significant differences in age,gender,tumor location,calcification,unenhanced CT and CECT attenuation values,and enhancement degree between the two groups(P>0.05).However,a significant difference was observed in tumor size(3.14±0.94 vs 6.63±3.26 cm,P<0.001)between the low-grade and high-grade groups.The univariate analysis further revealed that CT imaging features,including tumor contours,lesion growth patterns,ulceration,cystic degeneration or necrosis,lymphadenopathy,and contrast enhancement patterns,were associated with risk stratification(P<0.05).According to binary logistic regression analysis,tumor size[P<0.001;odds ratio(OR)=26.448;95%confidence interval(CI):4.854-144.099)],contours(P=0.028;OR=7.750;95%CI:1.253-47.955),and mixed growth pattern(P=0.046;OR=4.740;95%CI:1.029-21.828)were independent predictors for risk stratification of gastric GISTs.ROC curve analysis for the multinomial logistic regression model and tumor size to differentiate high-malignant potential from low-malignant potential GISTs achieved a maximum area under the curve of 0.919(95%CI:0.863-0.975)and 0.940(95%CI:0.893-0.986),respectively.The tumor size cutoff value between the low and high malignant potential groups was 4.05 cm,and the sensitivity and specificity were 93.5%and 84.2%,respectively.CONCLUSION CT features,including tumor size,growth patterns,and lesion contours,were predictors of malignant potential for primary gastric GISTs.

Clinical presentations of gastric small gastrointestinal stromal tumors mimics functional dyspepsia symptoms

AIM: To explore whether clinical presentations of gastric small gastrointestinal tumors (GISTs) mimics gastrointestinal dyspepsia symptoms.

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.

Gastric carcinoid tumor in a patient with a past history of gastrointestinal stromal tumor of the stomach

Gastrointestinal stromal tumor is the most common mesenchymal tumor in the gastrointestinal tract. It may coexist with other type of cancers,and if so,the tumors usually involve the stomach. The most common associated cancers are gastrointestinal carcinomas. We report a 65-year-old woman with a history of gastric gastrointestinal stromal tumor who had undergone subtotal segmental gastrectomy. New polypoid lesions were detected on a follow-up gastroscopy one year later. The lesions were biopsied and found to be carcinoid tumors. There was serum hypergastrinemia,and type 1 gastric carcinoid tumor was diagnosed. A total gastrectomy was performed. Pathologic examination revealed both carcinoid tumors and a recurrent gastrointestinal stromal tumor.

Heavily calcified gastrointestinal stromal tumors:Pathophysiology and implications of a rare clinicopathologic entity

Gastrointestinal stromal tumors(GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, and are characterized by a broad spectrum of clinical, histological and molecular features at presentation. Although focal and scattered calcifications are not uncommon within the primary tumor mass, heavy calcification within a GIST is rarely described in the literature and the clinical-biological meaning of this feature remains unclear. Cases with such an atypical presentation are challenging and may be associated with diagnostic pitfalls. Herein, we report a gastric GIST with the unusual presentation of prominent calcifications that was identified incidentally on imaging during a post-trauma diagnostic work-up. The patient underwent laparoscopic surgery with a radical resection of the mass, which was subsequently characterized by histological analysis as spindle-shaped tumor cells, positive for CD117/c-KIT, CD34 and DOG1, and with calcified areas. Given the intermediate risk of recurrence, no adjuvant therapy was recommended andthe patient underwent regular follow-up for 22 mo, with no evidence of relapse. Our case can be considered of interest because of the rarity of clinical presentation and the uniquely large size of the GIST at diagnosis(longest diameter exceeding 9 cm). In closing, we discuss the pathophysiology and clinical implications of calcifications in GISTs by reviewing the most up-to-date relevant literature.

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.

Diagnosis and management of small bowel neuroendocrine tumors:A state-of-the-art

This review provides an update on the epidemiology,pathophysiology,symptoms,diagnosis and treatment of neuroendocrine neoplasms(NENs)of the small bowel(SB).These NENs are defined as a group of neoplasms deriving from neuroendocrine cells.NENs are currently the most common primary tumors of the SB,mainly involving the ileum,making the SB the most frequently affected part of the gastrointestinal tract.SB NENs by definition are located between the ligament of Treitz and the ileocecal valve.They are characterized by small size and induce an extensive fibrotic reaction in the small intestine including the mesentery,resulting in narrowing or twisting of the intestine.Clinical manifestations of bowel functionality are related to the precise location of the primary tumor.The majority of them are non-functional NENs and generally asymptomatic;in an advanced stage,NENs present symptoms of mass effect by non-specific abdominal pain or carcinoid syndrome which appears in patients with liver metastasis(around 10%).The main manifestations of the carcinoid syndrome are facial flushing(94%),diarrhea(78%),abdominal cramps(50%),heart valve disease(50%),telangiectasia(25%),wheezing(15%)and edema(19%).Diagnosis is made by imaging or biochemical tests,and the order of request will depend on the initial diagnostic hypothesis,while confirmation will always be histological.All patients with a localized SB NEN with or without near metastasis in the mesentery are recommended for curative resection.Locoregional and distant spread may be susceptible to several therapeutic strategies,such as chemotherapy,somatostatin analogs and palliative resection.

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.

Laparoscopic resection of gastric gastrointestinal stromal tumors presenting as left adrenal tumors

Gastrointestinal stromal tumors (GISTs) are rare gastrointestinal malignancies. They are rarely seen near the urinary tract. In a literature review, only one case of GIST presenting as a left adrenal tumor was reported. We report two documented cases of gastric GISTs mimicking left adrenal tumors which were successfully treated with pure laparoscopic adrenalectomy and wedge resection of the stomach by excising the tumor from the stomach with serial fi ring of endoscopic gastrointestinal staplers. The surgical margins were clear, and the patients recovered smoothly. No adjuvant therapy with imatinib was prescribed. During the surveillance for 9 mo and 44 mo respectively, no tumor recurrence and metastasis were documented. Laparoscopic tumor excision, when adhering to the principles of surgical oncology, seems feasible and the prognosisis favorable for such tumors.

Interventional digital subtraction angiography for small bowel gastrointestinal stromal tumors with bleeding

AIM: To retrospectively evaluate the diagnostic efficacy of interventional digital subtraction angiography (DSA) for bleeding small bowel gastrointestinal stromal tumors (GISTs).

Small intestinal hemolymphangioma treated with enteroscopic injection sclerotherapy: A case report and review of literature

BACKGROUND Hemolymphangiomas are rare malformations composed of both lymphatic and vascular vessels and are located in the pancreas,spleen,mediastinum,etc.Small intestinal hemolymphangioma is extremely rare and often presents as obscure gastrointestinal bleeding.It is rarely diagnosed correctly before the operation.Endoscopic injection sclerotherapy is usually used as a management of bleeding in esophageal varices and was occasionally reported as a treatment of vascular malformation.The treatment of small intestinal hemolymphangioma with enteroscopic injection sclerotherapy has not been reported.CASE SUMMARY A 42-year-old male complained of recurrent episodes of melena and dizziness,fatigue and reduced exercise capacity for more than 2 mo.Gastroduodenoscopy and blood test revealed a gastric ulcer and anemia.Treatment with oral protonpump inhibitors and iron did not improve symptoms.We then performed a capsule endoscopy and anterograde balloon-assisted enteroscopy and revealed a hemolymphangioma.Considering it is a benign tumor without malignant potential,we performed enteroscopic injection sclerotherapy.He was discharged 4 days later.At follow-up 3 mo later,the melena disappeared.Balloon-assisted enteroscopy revealed an atrophied tumor atrophied and no bleeding.Argon plasma coagulation was applied to the surface of the hemolymphangioma to accelerated healing.When he returned for follow-up 1 year later,anemia was resolved and the tumor had been cured.CONCLUSION Balloon-assisted enteroscopy and capsule endoscopy are effective methods for diagnosis of hemolymphangioma.Enteroscopic injection sclerotherapy is an effective treatment.

Laparoscopic wedge resection of synchronous gastric intraepithelial neoplasia and stromal tumor:A case report

Synchronous occurrence of epithelial neoplasia and gastrointestinal stromal tumor(GIST)in the stomach is uncommon.Only rare cases have been reported in the literature.We present here a 60-year-old female case of synchronous occurrence of gastric high-level intraepithelial neoplasia and GIST with the features of 22 similar cases and detailed information reported in the Englishlanguage literature summarized.In the present patient,epithelial neoplasia and GIST were removed en bloc by laparoscopic wedge resection.To the best of our knowledge,this is the first reported case treated by laparo-scopic wedge resection.

Laparoscopicmanagementofgastricgastrointestinalstromaltumors

Gastrointestinal stromal tumors (GISTs) are the most frequent gastrointestinal tumors of mesodermal origin. Gastric GISTs represent approximately 70% of all gas-trointestinal GISTs. The only curative option is surgical resection. Many surgical groups have shown good results with the laparoscopic approach. There have not been any randomized controlled trials comparing the open vs laparoscopic approach, and all recommenda-tions have been based on observational studies. The experience obtained from gastric laparoscopic surgery during recent decades and the development of specific devices have allowed the treatment of most gastric GISTs through the laparoscopic approach.

Small Intestine Gastrointestinal Stromal Tumour—A Case Report

Gastrointestinal stromal tumours (GIST) are mesenchymal tumours that arise most commonly from the stomach. They are the 3rd most common tumour diagnosed behind adenocarcinomas and lymphomas. The majority of these tumours are asymptomatic and incidentally diagnosed in UGI scopy or contrast enhanced CT abdomen and pelvis studies. Obstruction, ulceration, gastrointestinal (GI) haemorrhage and perforation warrants an urgent surgical intervention. GIST is medically managed by tyrosine kinase inhibitors and surgically by resection and anastomosis. This case report highlights the diagnosis and management of a 42-year-old gentleman who presented with vague right iliac fossa mass. Informed consent was obtained from the patient for publication of this case. This case was chosen to be reported because of the rare incidence of small intestine GIST in South India and the effectiveness of minimally invasive laparoscopic surgery in management.

A rare synchrony of adenocarcinoma of the ampulla with an ileal gastrointestinal stromal tumor: A case report

BACKGROUND This is a unique case of a patient who was found to have two extremely rare primary malignancies synchronously,i.e.,an ampullary adenocarcinoma arising from a high-grade dysplastic tubulovillous adenoma of the ampulla of Vater(TVAoA)with a high-grade ileal gastrointestinal stromal tumor(GIST).Based on a literature review and to the best of our knowledge,this is the first report of this synchronicity.Primary ampullary tumors are extremely rare,with an incidence of four cases per million population,which is approximately 0.0004%.Distal duodenal polyps are uncommon and have a preponderance of occurring around the ampulla of Vater.An adenoma of the ampulla(AoA)may occur sporadically or with a familial inheritance pattern,as in hereditary genetic polyposis syndrome such as familial adenomatous polyposis syndrome(FAPS).We report a case of a 77-year-old male who was admitted for painless obstructive jaundice with a 40-pound weight loss over a two-month period and who was subsequently diagnosed with two extremely rare primary malignancies,i.e.,an adenocarcinoma of the ampulla arising from a high-grade TVAoA and a high-grade ileal GIST found synch-ronously.CASE SUMMARY A 77-year-old male was admitted for generalized weakness with an associated weight loss of 40 pounds in the previous two months and was noted to have painless obstructive jaundice.The physical examination was benign except for bilateral scleral and palmar icterus.Lab results were significant for an obstructive pattern on liver enzymes.Serum lipase and carbohydrate antigen-19-9 levels were elevated.Computed tomography(CT)of the abdomen and pelvis and magnetic resonance cholangiopancreatography were consistent with a polypoid mass at the level of the common bile duct(CBD)and the ampulla of Vater with CBD dilatation.The same lesions were visualized with endoscopic retrograde cholangiopancreatography.Histopathology of endoscopic forceps biopsy showed TVAoA.Histopathology of the surgical specimen of the resected ampulla showed an adenocarcinoma arising from the TVAoA.Abdominal and pelvic CT also showed a coexisting heterogeneously enhancing,lobulated mass in the posterior pelvis originating from the ileum.The patient underwent ampullectomy and resection of the mass and ileo-ileal side-to-side anastomosis followed by chemoradiation.Histopathology of the resected mass confirmed it as a high-grade,spindle cell GIST.The patient is currently on imatinib,and a recent follow-up positron emission tomography(PET)scan showed a complete metabolic response.CONCLUSION This case is distinctive because the patient was diagnosed with two synchronous and extremely rare high-grade primary malignancies,i.e.,an ampullary adenocarcinoma arising from a highgrade dysplastic TVAoA with a high-grade ileal GIST.An AoA can occur sporadically and in a familial inheritance pattern in the setting of FAPS.We emphasize screening and surveillance colonoscopy when one encounters an AoA in upper endoscopy to check for FAPS.An AoA is a premalignant lesion,particularly in the setting of FAPS that carries a high risk of metamorphism to an ampullary adenocarcinoma.Final diagnosis should be based on a histopathologic study of the surgically resected ampullary specimen and not on endoscopic forceps biopsy.The diagnosis of AoA is usually incidental on upper endoscopy.However,patients can present with constitutional symptoms such as significant weight loss and obstructive symptoms such as painless jaundice,both of which occurred in our patient.Patient underwent ampullectomy with clear margins and ileal GIST resection.Patient is currently on imatinib adjuvant therapy and showed complete metabolic response on follow up PET scan.

Plexiform angiomyxoid myofi broblastic tumor of the stomach

Plexiform angiomyxoid myofibroblastic tumor of the stomach is a unique mesenchymal tumor that we first described in 2007.The tumor is very rare,and to date,only 18 cases confirmed by immunohistochemistry have been reported in the literature.The patients' ages ranged from 7 to 75 years(mean,43 years),and the male-to-female ratio was approximately 1:1.Representative clinical symptoms are ulceration,associated upper gastrointestinal bleeding(hematemesis),and anemia.The tumors are located at the antrum in all cases,and grossly,the tumor is whitish to brownish or reddish,and forms a lobulated submucosal or transmural mass.Microscopically,the tumor is characterized by a plexiform growth pattern,the proliferation of cytologically bland spindle cells,and a myxoid stroma that is rich in small vessels and positive for Alcian blue stain.Immunohistochemically,the tumor cells are positive for α-smooth muscle actin and negative for KIT and CD34.Differential diagnoses include gastrointestinal stromal tumor and other mesenchymal tumors of the gastrointestinal tract.Some authors proposed that this tumor should be designated as "plexiform fibromyxoma",but this designation might cause confusion.The tumor is probably benign and thus far,neither recurrence nor metastasis has been reported.

Small bowel tumors detected and missed during capsule endoscopy: Single center experience

AIM:To characterize small bowel(SB)tumors detected by capsule endoscopy(CE),and identify missed tumors.METHODS:The study included 145 consecutive patients in whom 150 CEs were performed.Following CE,the medical records of the study population were reviewed.Results of double-or single-balloon enteroscopy performed after CE and the results of surgery in all patients operated on were retrieved.The patients were contacted through telephone interviews or postal mail.In addition,the national cancer registry and the polish clinical gastrointestinal stromal tumor(GIST)Registry were searched to identify missed neoplasms.RESULTS:Indications for CE included overt and occult obscure gastrointestinal bleeding(n=81,53.7%),anemia(n=19,12.7%),malabsorption(n=18,12%),abnormal CB follow through(n=9,6%),abdominal pain(n=7,5%),celiac disease(n=5,3%),neuroendocrine tumor(n=3,2%),Crohn’s disease(n=2,<2%),Peutz-Jeghers syndrome(n=2,<2%),other polyposes(n=2,<2%),and diarrhea(n=2,<2%).The capsule reached the colon in 115(76.6%)examinations.In 150 investigations,CE identified 15SB tumors(10%),14 of which were operated on or treated endoscopically.Malignancies included metastatic melanoma(n=1),adenocarcinoma(n=2),and GIST(n=3).Benign neoplasms included dysplastic Peutz-Jeghers polyps(n=4).Non-neoplastic masses included venous malformation(n=1),inflammatory tumors(n=2),and a mass of unknown histology(n=1).During the follow-up period,three additional SB tumors were found(2 GISTs and one mesenteric tumor of undefined nature).The National Cancer Registry and Polish Clinical GIST Registry revealed no additional SB neoplasms in the post-examination period(follow-up:range 4.2-102.5 mo,median 39 mo).The sensitivity of CE for tumor detection was 83.3%,and the negative predictive value was 97.6%.The specificity and positive predictive value were both 100%.CONCLUSION:Neoplasms may be missed by CE,especially in the proximal SB.In overt obscure gastrointestinal bleeding,complementary endoscopic and/or radiologic diagnostic tests are indicated.