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 of small 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.     

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 indi     

Synchronous incidental gastrointestinal stromal and epithelial malignant tumors

AIM： To investigate the incidence of incidental gastrointestinal stromal tumor （GIST） and its etiopathogenesis. METHODS： From January 1, 2000 to December 31, 2007, 13804 cases of gastrointestinal epithelial malignant tumor （EMT） and 521 cases of pancreatic adenocarcinoma （PAC） were successfully treated with surgery at the Department of General Surgery and the Department of Thoracic Surgery, West China Hospital, Sichuan University, China. The clinical and pathologic data of 311 cases of primary GIST, including 257 cases with clinical GIST and 54 cases of incidental GIST were analyzed. RESULTS： Of the 311 patients, 54 had incidental GIST, accounting for 17.4%. Of these tumors, 27 were found in 1.13% patients with esophageal squamous cell carcinoma （ESCC）, 22 in 0.53% patients with gastric adenocarcinoma （GAC）, 2 in 0.38% patients with PAC, 2 in 0.03% patients with colorectal adenocarcinoma, and 1 in one patient with GAC accompanying ESCC, respectively. Patients with incidental GIST presented symptoms indistinguishable from those with EMT. All incidental GIST lesions were small in size, and the majority had a low mitotic activity while only 1.9% （5/257） of clinical GIST lesions had a high risk.CONCLUSION： Incidental GIST may occur synchronously with other tumors and has a high prevalence in males. Surgery is its best treatment modality.     

Double-Balloon Enteroscopy and Small Bowel Tumors: A South-European Single-Center Experience

Small bowel tumors are rare, accounting for 1–2% of all gastrointestinal neoplasms. We sought to determine the diagnostic and therapeutic impact of double-balloon enteroscopy (DBE) in patients with small bowel tumors. Between January 2005 and March 2008, 78 patients underwent 96 DBE. All nine patients (seven males; mean age 68 ± 11.3 years) with small bowel tumors were retrospectively reviewed. Clinical presentation was: mid-gastrointestinal bleeding or iron-deficient anemia (55.6%); abdominal pain (22.2%); nausea/vomiting and abdominal distension (22.2%). Five patients had abnormal findings in previous capsule endoscopy and four in previous radiologic examinations. Route of insertion was exclusively oral and abnormal lesions were detected in all patients (jejunum 8; ileum 1). Biopsies were taken in seven patients and provided definitive histological diagnosis in all except one. There were no complications of DBE. Surgical resection took place in eight patients. Final histologic diagnosis were: primary carcinoma (33.3%), gastrointestinal stromal tumor (GIST) (33.3%), malignant lymphoma (22.2%), and carcinoid tumor (11.1%). Mean follow-up time was 15.4 ± 12.7 months (range 2–34 months). Six patients were submitted to chemotherapy. Two patients died. Small bowel tumors are common in patients submitted to DBE. Given its safety and diagnostic capabilities, DBE should be considered the gold-standard method in the study of these neoplasms.     

Capability of Capsule Endoscopy in Detecting Small Bowel Ulcers

Capsule endoscopy (CE) has proved to be the preferred modality for mucosal pathologies of the small bowel. We evaluated the capability of CE for detecting small bowel ulcers and the contribution of CE in establishing the diagnosis. From a total of 66 patients who had undergone normal upper and lower endoscopy and small bowel follow-through, CE revealed previously undiagnosed ulcer(s) in the small intestines of 22 patients. Final diagnoses of the ulcers of these 22 patients were Crohn's disease (n = 9), Beh?et's disease (n = 2), nonspecific jejunoileitis (n = 2), vasculitis (n = 1), gastrointestinal stromal tumor (n = 1), adenocarcinoma (n = 1), lymphoma (n = 1), multiple myeloma (n = 1), Meckel's diverticulum (n = 1) and unknown (n = 3). Capsule endoscopy was extremely useful in establishing the diagnosis. In this study, proximal, distal and diffuse small bowel ulcers were determined at rates of 27.3, 59.0 and 13.7%, respectively. Capsule endoscopy facilitated the detection and assessment of ulcerated mucosal lesions located in the small bowel.     

Capsule endoscopy in small bowel tumors: A multicenter Korean study

Background and Aim: Capsule endoscopy (CE) has proven to be highly effective at detecting small bowel lesions in a variety of clinical conditions, but studies concerning the practical impact of CE on small bowel tumors are still scarce, especially in the Asian population. The aim of this study was to evaluate the diagnostic and therapeutic impact of CE in the field of small bowel tumors. Methods: CE records consecutively pooled from the beginning of use of CE in Korea, October 2001 until April 2008, in 14 centers throughout Korea were reviewed. Clinical information and CE video images of small bowel tumors were analyzed. Results: A total of 1332 cases undergoing CE were reviewed with all clinical indications. Small bowel tumors were diagnosed with CE in 57 (4.3%) of 1332 patients. The tumors were malignant in 33 cases, and included three adenocarcinomas, eight lymphomas, 20 gastrointestinal stromal tumors, and two metastatic cancers. The most frequent indications for CE in malignant tumors were obscure gastrointestinal bleeding, followed by abdominal pain and weight loss. Thirty of 57 tumors were identified exclusively by CE (diagnostic impact = 30/57), and they were smaller in size (mean, range: 14.3 mm, 2–35 mm) compared to the other tumors detected in radiological studies (48.7 mm, 10–110 mm). Seven patients underwent surgical resection (therapeutic impact = 7/57). Conclusion: CE effectively identifies small bowel tumors that are undetectable by conventional radiological studies (diagnostic impact = 52.6%) and can critically change the therapeutic course (therapeutic impact = 12.3%).     

P53 and MIB-1 expression in gastrointestinal stromal tumor (GIST) of the stomach

BACKGROUND/AIMS: Routine clinical approaches for evaluating the risk of recurrence in patients with gastrointestinal stromal tumor (GIST) of the stomach have been limited. Some biomolecular markers may yield more useful information in identifying patients having a higher risk of recurrence. In the current retrospective study, we selected MIB-1 and p53 expression as markers to detect at-risk patients. METHODOLOGY: We enrolled 31 gastric GIST patients who underwent gastrectomy at Kagoshima University Hospital. Patients were classified into two groups based on mitosis and tumor diameter. p53 and MIB-1 expression in the primary tumor were detected immunohistochemically. RESULTS: The patients were classified as having a malignant GIST (20 cases), a benign GIST (11 cases). MIB-1 labeling index (LI) varied from 1 to 32% (average 7.8%). The MIB-1 LI for malignant GISTs was 6.3 +/- 6.4%, which was significantly higher than the 3.2 +/- 2.5% observed for benign GISTs (p < 0.01). The 3 patients positive for p53 died as a result of GIST recurrence. CONCLUSIONS: In addition to routine pathological evaluation, expression of p53 and MIB-1 may provide more accurate information regarding the risk of GIST recurrence. Especially, p53 expression of the tumor may indicate patients having a high risk of recurrence.     

Small bowel cancer: single-centre results over a period of 12 years

BACKGROUND/AIMS: Tumors of the small bowel are rare, accounting for about 3-6% of all gastrointestinal neoplasms. However, diagnosis and treatment are difficult and an ongoing challenge. METHODOLOGY: Follow-up and clinical data of 43 patients with small bowel cancer who underwent surgery at our hospital. RESULTS: Subgroups consisted of adenocarcinoma (n=16; 37.2%), neuroendocrine tumors (n=12; 27.9%), gastrointestinal stroma tumor (GIST) (n=10; 23.3%), lymphoma (n=3; 7%) and desmoid tumor (n=2; 4.6%). Tumor localizations were within duodenum (46.5%), jejunum (16.3%) and ileum (37.2%). Thirty patients were curatively operated, 13 for palliative treatment or diagnostic purpose. Adenocarcinoma patients showed preponderance of advanced tumor stages: stage I/II in 5 pts, III/IV in 11 patients. Stage distribution for patients with neuroendocrine tumors was 3 each for I and II and 6 for III. Localization was predominantly within the ileum (n=7). Overall survival after five/ten years was 48/37%. Patients with neuroendocrine tumors showed best survival results (75/57%), GIST patients 60/35% and adenocarcinoma (27% each). There was a strong trend towards better survival at early tumor stages in patients with adenocarcinoma and neuroendocrine tumors. CONCLUSIONS: Early diagnosis is essential for prognosis of small bowel malignancies. Cure is unlikely if lymph node or distant metastases have already developed.     

胃肠道间质瘤110例临床诊治分析

目的 研究胃肠道间质瘤(gastrointestinal stromaltumor,GIST)的临床特点、治疗方法和预后.方法 对2002年2月至2008年7月110例经手术后病理确诊为GIST患者的临床资料进行回顾性分析.结果 所有患者的GIST主要起源于胃(50.9%)和小肠(31.8%),103例(93.6%)有临床症状.最常见的临床表现为消化道出血、腹痛和腹部肿块.手术病理结果发现良性14例(1 2.7%),交界性37例(33.6%),恶性59例(53.6%).免疫组化检测CD117、CD34的阳性率分别为98.2%(108/110)和77.3%(85/110).81.8%的患者进行了根治性的手术切除.15例手术时已转移的GIST和6例复发的GIST行伊马替尼治疗,15例可评估,临床获益率80.0%.结论 GIST临床表现缺乏特异性,确诊须依赖大体标本或免疫组化病理结果,CD117对诊断有重要价值.肿瘤的完整切除是主要治疗方法,分子靶向药物伊马替尼能延长晚期GIST患者的生存期.     

Capsule endoscopy in patients with malignant melanoma

BACKGROUND: Although small bowel (SB) involvement is found at postmortem in 50-60% of melanoma patients, diagnosis is only made during life in 10% of cases. This study reports the findings of capsule endoscopy (CE) in melanoma patients referred for investigation of suspected SB involvement. METHODS AND SUBJECTS: Eight men and five women with known or previous melanoma were referred for CE between December 2003 and September 2006. The indications were gastrointestinal bleeding (three), anemia (six), positive fecal occult blood test (one), abnormal imaging (two), and abdominal pain (one). RESULTS: CE showed SB metastases in five patients and excluded SB involvement in eight. All patients had previous investigations with either endoscopy, push enteroscopy, SB follow-through, CT scan, and/or PET scan. CE showed new lesions not detected by other investigation modalities. CE also ruled out SB metastases when other tests were nondiagnostic. All five patients with SB metastases detected underwent surgical resection. At follow-up after CE of a mean 8.4 months (1-23 months) and 4.9 months (0.25-10 months) after surgery, five patients had died, including three of those who had undergone resection of SB metastases. Seven patients were still alive, including two who had SB surgery. One patient was lost to follow-up. CONCLUSIONS: CE may detect the presence and extent of SB metastases in patients with melanoma more reliably than conventional investigations. It should be considered in the workup of melanoma patients with suspected SB disease.     

胃肠间质瘤个体化治疗策略的探讨

胃肠间质瘤（GIST）是最常见的胃肠道间叶源性肿瘤，多见于胃和小肠，GIST多具有恶性潜能，生物学行为可以从良性到高度恶性不等。GIST的预后与肿瘤的发病部位、瘤体大小、核分裂数以及肿瘤是否破裂密切相关，伊马替尼辅助治疗明显延长了GIST患者的生存时间。近年对于GIST患者实施个体化治疗的理念也得到了越来越多的重视，本文就GIST个体化治疗的策略研究进行阐述。     

Advanced gastrointestinal stromal tumor patients with complete response after treatment with imatinib mesylate

AIM: Most gastrointestinal stroma! tumors (GISTs) express constitutively activated mutant isoforms of kit kinase or platelet-derived growth factor receptor alpha (PDGFRA), which are potential therapeutic targets for imatinib mesylate (Glivec). Partial response occurred in almost two thirds of GIST patients treated with Glivec. However, complete response (CR) after Glivec therapy was sporadically reported. Here we illustrated advanced GIST patients with CR after Glivec treatment. METHODS: Between January 2001 and June 2005, 42 advanced GIST patients were treated with Glivec. Patients were administered 400 mg of Glivec in 100-mg capsules, taken orally daily with food. The response of the tumor to Glivec was evaluated after one month, three months, and every three months thereafter or whenever medical need was indicated. Each tumor of patients was investigated for mutations of kit or PDGFRA. RESULTS: The median follow-up time of the 42 ad-vanced GIST patients treated with Glivec was 16.9 months (range, 1.0-47.0 months). Overall, 3 patients had complete response CR (7.1%), 26 partial response (67.8%), 5 stationary disease (11.9%), and 3 progressive disease (11.9%). The median duration of Glivec administration for the three patients was 36 months (range, 23-36 months). The median time to CR after Glivec treatment was 20 months (range, 9-26 months). Deletion and insertion mutations of c-kit exon 11 and insertion mutation of c-kit exon 9 were found in two cases and one case, respectively. CONCLUSION: Complete response (CR) can be achieved in selected advanced GIST patients treated with Glivec. The median time to CR after Glivec treatment was 20 months. Deletion and insertion mutations of kit exon 11 and insertion mutation of kit exon 9 contribute to the genetic features in these selected cases.     

Diagnostic effect of capsule endoscopy in 31 cases of subacute small bowel obstruction

AIM： TO evaluate the effectiveness and safety of capsule endoscopy （CE） in patients with recurrent subacute small bowel obstruction.METHODS： The study was a retrospective analysis of 31 patients referred to hospital from January 2003 to August 2008 for the investigation of subacute small bowel obstruction, who underwent CE. The patients were aged 9-81 years, and all of them had undergone gastroscopy and colonoscopy previously. Some of them received abdominal computed tomography or small bowel follow-through.RESULTS： CE made a definitive diagnosis in 12 （38.7%） of 31 cases： four Crohn＇s disease （CD）, two carcinomas, one intestinal tuberculosis, one ischemic enteritis, one abdominal cocoon, one duplication of the intestine,one diverticulum and one ileal polypoid tumor. Capsule retention occurred in three （9.7%） of 31 patients, and was caused by CD （2） or tumor （1）. Two with retained capsules were retrieved at surgery, and the other one of the capsules was spontaneously passed the stricture by medical treatment in 6 too. No case had an acute small bowel obstruction caused by performance of CE.CONCLUSION： CE provided safe and effective visualization to identify the etiology of a subacute small bowel obstruction, especially in patients with suspected intestinal tumors or CD, which are not identified by routine examinations.     

Small-bowel masses found and missed on capsule endoscopy for obscure bleeding

OBJECTIVE: Data on the nature of small-bowel tumors found or missed by capsule endoscopy (CE) are limited. The aim of this study was to review the CE findings in patients with small-bowel tumors presenting as obscure gastrointestinal (GI) bleeding. MATERIAL AND METHODS: We retrospectively reviewed the medical records of the first 300 patients who underwent CE for obscure bleeding (non-diagnostic EGD and colonoscopy) at our institution. RESULTS: Ten (3%) confirmed small-bowel masses were found in 9 patients. CE findings included distinct mass (n=4), focal irregular (ulcerated or nodular) mucosa (n=2), focal blood without clear lesion (n=1), proximal angiodysplasia with obscuring distal melena (n=1), incomplete distal examination with normal proximal images (n=1), and normal findings (n=1). Most (80%) of the lesions were potentially malignant: adenocarcinoma (n=4), neuroendocrine carcinoma (n=1), leiomyosarcoma (n=1), and GI stroma cell tumors (GISTs) (n=2). Benign lesions included inflammatory fibroid polyp (n=1) and lipoma (n=1). Three duodenal masses were missed on a previous EGD; one was missed by CE as well. CE findings led directly to tumor diagnosis in 7 of the 10 cases. Capsule retention occurred in 2 of the 10 cases, with one patient requiring urgent surgery for acute obstruction. CONCLUSIONS: Small-bowel tumors are a rare but serious source of obscure GI bleeding. Our large single-center experience shows that most lesions are of malignant potential. Tumors can have an atypical appearance including focal ulceration, nodularity, or active bleeding without a clear lesion. Mass lesions in the duodenum are particularly elusive and can be missed by both EGD and CE.     

Is a 2-liter PEG preparation useful before capsule endoscopy?

AIMS: Small bowel contents can sometimes hamper the quality of capsule images. Our aim was to investigate the effect of PEG administered prior to capsule endoscopy (CE) upon quality of images, gastrointestinal transit time, and detection rate of small bowel bleeding lesions in patients with obscure gastrointestinal bleeding. PATIENTS AND METHODS: Forty-two consecutive patients were included. CE was performed following a 12-hour fasting period. The 16 first patients (Group A) received no preparation and the following 27 patients (Group B) received 2 L of PEG the night before. The quality of images was assessed at both in duodenojejunum and ileum level, using a scale including the presence of air bubbles, biliary secretion, and residue (1-4). RESULTS: Quality of images were not different in Group A compared with Group B in the duodenojejunum and in the ileum. Gastric transit time tended to be shorter in Group A compared with Group B (25.5 vs. 45.7 minutes) (P = 0.15), whereas small bowel transit was not different between both groups (271 vs. 288 minutes). Total small bowel CE examination was complete in Group A and in 24 of 26 in Group B (not significant). Potential bleeding lesions were seen in 8 patients in Group A and 12 in Group B (not significant). CONCLUSION: Our retrospective study suggests that 2 L PEG preparation seems able to improve neither the quality of CE images nor its diagnostic performance. Moreover, in our study, PEG tended to increase gastric emptying time and may constitute a limitation for small bowel complete examination.     

Small-Bowel Tumors Detected by Wireless Capsule Endoscopy

Small bowel tumors are difficult to diagnose because of their endoscopic inaccessibility. This has been overcome by the use of the Pillcam™ SB capsule (Given Imaging, Yoqneam, Israel). The purpose of this report is to describe the largest series of patients with small bowel tumors detected by capsule endoscopy. Eighty six patients were derived from the Given Imaging clinical database on a survey of Pillcam™ SB capsule users who were diagnosed with 87 small bowel tumors, 1 cecal tumor, and 1 gastric tumor. The population consisted of 55 males and 31 females. 69% of patients were referred for capsule endoscopy for obscure gastrointestinal bleeding (59/86 patients) and 31% (27/86 patients) were referred for other indications including anemia, polyposis, and abdominal pain. All patients have histologically confirmed tumors. Eighty six patients reported 395 previous negative procedures (average of 4.6 per patient). Malignant tumors comprised 61% (54/89) and benign 39% (35/89). Of the 87 reported small bowel tumors, 4 were identified in the duodenum, 43 tumors were identified in the jejunum, 18 tumors were identified in the ileum, and 22 tumors were located in the mid to distal small bowel. The most common malignant tumors were adenocarcinoma, carcinoids, melanomas, lymphomas, and sarcomas. The most common benign tumors were GIST, hemangiomas, hamartomas, adenomas, and granulation tissue polyps. Capsule endoscopy is the diagnostic procedure of choice in patients with suspected small bowel tumors.     

Angiographic findings of gastrointestinal stromal tumor

AIM: To discuss the angiographic features of gastrointestinal stromal tumor (GIST) and to evaluate their diagnostic role. METHODS: Twelve patients with pathologically proved GIST underwent angiography (DSA)1 wk before operation, using Puck and digital subtraction DSA. The origin, size, morphology and angiographic appearance of the lesions were reviewed. RESULTS: Two tumors arose from stomach, 8 from jejunum, and 2 from ileum. Seven cases were benign and 5 were malignant. Obviously thickened supplying arteries were detected in 8 tumors, and early-developed veins were found in 3. Two types of angiographic changes of GIST were observed. Four cases had twisted irregular neoplastic vessels with partially coarse and indistinct margins, which were all malignant. Eight cases had ball-like neoplastic vessels with uniform tumor staining, of which 7 were benign and 1 was malignant. CONCLUSION: Angiography facilitates localization and diagnosis of GIST, helps define their size, range and location, and is especially valuable to patients suffering from melena with unknown reasons.     

Study of the expressions of p53 and bcl-2 genes, the telomerase activity and apoptosis in GIST patients

AIM: To explore the relationship between clinicobiological behavior and the expression levels of telomerase activity, apoptosis, p53 gene and bcl-2 gene in gastrointestinal stromal tumors (GISTs). METHODS: The intensity of telomerase activity, apoptosis, p 53 and bcl -2 expression in GISTs were detected by telomeric repeat amplification protocol, in situ end-labeling technique, and immunohistochemistry, respectively. RESULTS: The positive rates of telomerase activity of malignant GIST, potential malignant GIST and benign GIST were 85% (17/20), 22.8% (2/9) and 0 (0/9), respectively. The apoptosis indices of malignant GIST, potential malignant GIST, and benign GIST were 11.7 ± 5.4, 30.2 ± 5.6 and 45.2 ± 7.2, respectively. The intensity of telomerase activity and apoptosis were related to the biological characteristics of GISTs (85% vs 22.8%, 0, 0; P < 0.01 or 11.7 ± 5.4 vs 30.2 ± 5.6, 45.2 ± 7.2, 72.1 ± 9.3; P < 0.05). The intensity of telomerase activity was negatively correlated with cellular apoptosis (22.9 ± 8.4 vs 9.5 ± 5.7, P < 0.01). The intensity of telomerase activity was positively correlated with p53, bcl-2 expression (40.0% vs 78.9%, 40.0% vs 84.2%; P < 0.05). CONCLUSION: The detection of telomerase activity, apoptosis and its control genes in GIST will be helpful for the discrimination of the malignant and benign GIST and evaluation of the prognosis.     

The relationship between MIB-1 proliferative activity and mitotic index in gastrointestinal stromal tumors

BACKGROUND/AIMS: Gastrointestinal stromal tumors (GIST) are mesenchymal tumors originating from the gastrointestinal canal wall. Although a number of studies are performed concerning prognostic factors, no indicators of recurrence or metastasis could be established. In this study we assessed the prognostic value of MIB-1 proliferative index (PI) in GIST, and whether there was a relationship to any other clinicopathological findings. METHODOLOGY: In the study 37 patients with GIST diagnosis were included. The cases were classified as low, intermediate, and high risk groups according to tumor size and mitotic activity. The average PI of 10% in high risk group was set as the cut-off value. RESULTS: Of all the cases, those with a MIB-1 PI over the cut-off value had a significantly shorter survival (Log-rank test, p < 0.05). Likewise cases with small bowel tumors with a MIB-1 PI over the cut-off value had a significantly shorter survival (Log-rank test, p < 0.05). A statistically significant negative correlation was found between presence of necrosis and survival using McPearson correlation test (p < 0.01). CONCLUSIONS: MIB-1 PI and presence of necrosis are possible indicators of prognosis especially in GIST cases of the small bowel.