Location Of Gastrointestinal Stromal Tumors Research Articles

Is Bleeding Gastrointestinal Stromal Tumor Associated With Higher MortalityandMorbidity?

Introduction Gastrointestinal stromal tumor (GIST) is the most common primary mesenchymal tumor of the gastrointestinal tract. The clinical presentation of GIST varies widely and ranges from being asymptomatic to being a life-threatening emergency in the form of gastrointestinal bleeding or bowel obstruction. Multiple prognostic factors have been identified for GIST, including, most importantly, larger tumor size (>5 cm), higher mitotic activity (>5 per 50 high-power fields), rupture of the mass, site of the mass, and personal history of GIST. Objective In this paper, we aim to study bleeding in gastrointestinal tumors as a predictor for morbidity and mortality and investigate possible factors influencing bleeding in GIST. Method A retrospective study design was used. Electronic medical records of 39 patients diagnosed with GIST in Prince Sultan Military Medical City in Riyadh between January 2015 and December 2020 were retrieved. Normal variables were presented as mean and standard deviation, while non-normal variables were presented as median and interquartile range. Student t-test or Mann-Whitney test was used to compare quantitative data when appropriate. The distribution of recurrence and survival was plotted with the Kaplan-Meier curveand compared between the two groups (bleeding and non-bleeding groups) with the log-rank test. Factors affecting recurrence and mortality were assessed using univariable Cox regression. Result A total of 39 cases of GIST tumors were included in this study. Patients were categorized according to the presentation into two groups: patients with no bleeding (n= 28) and those presented with bleeding (n= 11). The gender distribution was equal. The mean age was 58.14± 12.46 in patients with non-bleeding GIST and 58.18± 16.01 in patients with bleeding GIST. The most common location of GIST was the stomach (22 cases, 56%). Neither group had any significant differences regarding age (P-value = 0.993), gender (P-value = 0.648), tumor location (P-value = 0.057), size (P-value = 0.250), cluster of differentiation (CD) markers, histological types (P-value = 0.692), and shape (P-value = 0.079). There was no significant difference in recurrence between both groups (log-rank P = 0.972). There was no significant difference in survival between both groups (Log-rank P = 0.506). Conclusion We concluded that bleeding GIST was not a significant predictor for recurrence rate or higher mortality. This can help in the debate of whether bleeding GIST should be added as an independent factor in risk stratification. Despite that, further studies are needed to identify more variables that can add more accuracy to the pre-existing risk stratification systems.

Case Report: Synchronous primary location of gastrointestinal stromal tumors (GIST) and adenocarcinoma of the colon: an unusual occurrence

Background: We have little knowledge about the synchronous occurrence of gastrointestinal stromal tumors (GISTs) and other types of histologic tumors. This association is very rare. Case presentation: We describe a case of synchronous stromal tumor and adenocarcinoma of the left side colonic localization. Immunohistochemistry identified c-Kit expression. The discovery of colonic adenocarcinoma was on operative specimen after histologic examination. The patient underwent left carcinologic colectomy with stoma. Follow-up at one year postoperatively did not detect tumor recurrence. Discussion: Clinical implications of the association between these two neoplasms are not clearly described. Treatment depends on the dominance of one histologic type. Knowledge of the genetic data of this association offers opportunity of treatment with the new targeted-therapy molecules. Surgical resection, may remain the curative treatment. Conclusions: Synchronous adenocarcinoma and GIST has been more commonly described in the stomach. The pathogeneses of tumorigenesis may not be the same for the two tumors. More studies seem be necessary to clarify a potential role of different genes in the development of adenocarcinomas. And therefore, above all their therapeutic implications

Prognostic Value of Bleeding in Gastrointestinal Stromal Tumors: A Meta-Analysis.

Background:Gastrointestinal bleeding is the most common clinical manifestation of gastrointestinal stromal tumor. It is of great significance to the prognosis of patients. But the results are controversial. The purpose of this study was to evaluate the relationship between gastrointestinal bleeding and clinical prognosis in patients with GIST.Methods:A systematic literature search was performed in Pumbed, Cochrane Library, EMBASE, ClinicalTrials.gov, CNKI, VIP and wanfang databases with the pattern of unlimited languages. 12 studies with 2781 individuals were included in the final analysis. The overall survival (OS), recurrence-free survival/disease-free survival (RFS/DFS) and related factors affecting bleeding in patients with gastrointestinal stromal tumor (GIST) were extracted. Hazard ratio (HR) and 95% confidence interval (CI) were used for in the meta-analysis.Results:A total of 12 articles were included in the study, including 2781 patients with GIST, including 845 patients with gastrointestinal bleeding. The OS of GIST patients with gastrointestinal bleeding was significantly worse (HR = 2.54, 95% CI = 1.13-5.73, P = 0.025). But there was no significant difference in RFS between gastrointestinal bleeding patients and non-bleeding patients (HR = 1.35, 95% CI = 0.70-2.61, P = 0.371). Further analysis of the related factors of GI bleeding in GIST patients was observed, besides the aging factor (HR = 1.02, 95% CI = 0.69-1.50, P = 0.929), Small intestinal stromal tumor (HR = 0.56, 95% CI = 0.41-0.76, P < 0.001), tumor diameter ≥ 5 cm (HR = 2.09, 95% CI = 1.20-3.63, P = 0.009), Mitotic index ≥ 5/50 HPF (HR = 1.66, 95% CI = 1.11-2.49, P = 0.014) and tumor rupture (HR = 2.04, 95% CI = 1.0-3.82, P = 0.026) all increased the risk of GI bleeding in patients with GIST.Conclusions:The OS of GIST patients with GI bleeding was worse than non-GI bleeding, but had no significant effect on RFS. Nevertheless the aging factor, the location of GIST in the small intestine, tumor diameter ≥ 5 cm, Mitotic index ≥ 5/50 HPF and tumor rupture all increased the risk of GI bleeding in patients with GIST.

Current characteristics on small intestinal stromal tumor-a case control study.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor in the gastrointestinal tract. Small intestine is the second most popular location of GIST, named small intestinal stromal tumor (SIST). The cumulative incidence of malignancy of SIST is twice that of gastric GIST. However, research studies on SIST are relatively rare. The present retrospective study included 75 patients with SIST who underwent surgery resection and postoperative pathological diagnosis and analyzed the clinical manifestations, histopathological and immunohistochemical features, advantages and disadvantages of various auxiliary examinations, the treatment and prognosis of SIST. The number of Patients who had gastrointestinal bleeding was significantly higher than patients who had abdominal mass. Cases in the jejunum was significantly more than that in duodenum and ileum groups. With the increase of tumor diameter, the invasion risk also gradually increased. Patients with adverse outcome had bigger tumor diameter than patients with favorable outcome. For patients with adverse outcome, the nuclear division >5/50 HPF constitution is significantly higher than patients with favorable outcome. When categorized into 3 cell types according to cell morphology, the spindle-epithelioid cell type appeared only in patients with adverse outcome. Cox regression analysis indicated that tumor diameter 5.3 cm or higher and nuclear division > 5/50 can be independent risk factors for predicting SIST postoperative adverse outcome. The present study analyzed the clinical statistics of SIST patients and improved the understanding of this disease and provided valid statistics for clinical diagnosis and treatment.

Management of gastrointestinal stromal tumors: A 10-year experience of a single surgical department.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive system. The primary location of GISTs is mainly the gastrointestinal system. Clinical symptoms are nonspecific and mainly depend on the location and size of the tumor. The aim of this study was to conduct a clinical and pathological analysis of 18 cases of GISTs from the medical records of the Department of Surgery at the 4th Military Teaching Hospital in Wrocław, Poland. The medical records were of women and men at the age of 36-84 years who were treated in the Surgical Clinic. The medical data that was gathered included clinical records, histopathological results and the type of surgical treatment. The study also encompassed the anatomical location and size of the tumor as well as microscopic examination of the tumor. In most cases, GISTs were located in the stomach. The most common symptoms were stomachaches and signs of bleeding into the digestive system. Usually, the tumor presented a diameter of <5 cm and a low grade of malignancy. Out of 18 patients, 16 were treated with laparoscopic resection, whereas in the remaining 2 cases, multiorgan resections were carried out, because the tumor was locally advanced. It is essential to distinguish stromal tumors from other mesenchymal tumors, since GISTs are among the cancers that have a high risk of malignant progression. The conditions for successful treatment are a properly established histopathological diagnosis, accompanied by immunohistochemical tests for CD117, and a combination of antibodies for a differential diagnosis of other mesenchymal tumors.

Clinical and Pathological Features of Gastrointestinal Stromal Tumors (GIST) in a Single Institution: A Descriptive Study and Review of the Literature

IntroductionThis study was aimed to assess the main clinical, pathological and therapeutic characteristics of a cohort of gastrointestinal stromal tumors (GIST). MethodsObservational study including 66 patients diagnosed with GIST admitted to our hospital between 2002 and 2015. Parameters related to medical history, clinical manifestations, medical and surgical treatment, histopathology, and morbi-mortality were studied. A review of the literature was included to correlate with the results. ResultsThe most frequent location of GIST in our patients was the stomach (65.2%), in which the gastric fondo was the predominant region. The most common clinical manifestation was gastrointestinal hemorrhage (45.5%), followed by incidental finding after imaging or invasive procedures (33.3%). 58 patients underwent surgery (90.6%), 15.5% were urgent. A total of 69% of the GISTs had a size between 2 and 10cm. The one-year mortality was 7.9%, all cases related to local or remote extension, or surgical complications. ConclusionThere is a large clinical variability among GIST cases. The first choice of treatment is surgery, which is feasible in most cases and should be as conservative as possible. The prognosis varies depending on the size and proliferation index, thus close follow-up should be performed. No tumor marker is clearly associated with a poor prognosis. New molecular biology studies are needed in order to find therapeutic targets.

Perfil clínico y anatomopatológico de los tumores estromales gastrointestinales de un hospital de área: Estudio descriptivo y revisión de la literatura

IntroductionThis study was aimed to assess the main clinical, pathological and therapeutic characteristics of a cohort of gastrointestinal stromal tumors (GIST). MethodsObservational study including 66 patients diagnosed with GIST admitted to our hospital between 2002 and 2015. Parameters related to medical history, clinical manifestations, medical and surgical treatment, histopathology, and morbi-mortality were studied. A review of the literature was included to correlate with the results. ResultsThe most frequent location of GIST in our patients was the stomach (65.2%), in which the gastric fondo was the predominant region. The most common clinical manifestation was gastrointestinal hemorrhage (45.5%), followed by incidental finding after imaging or invasive procedures (33.3%). 58 patients underwent surgery (90.6%), 15.5% were urgent. A total of 69% of the GISTs had a size between 2 and 10cm. The one-year mortality was 7.9%, all cases related to local or remote extension, or surgical complications. ConclusionThere is a large clinical variability among GIST cases. The first choice of treatment is surgery, which is feasible in most cases and should be as conservative as possible. The prognosis varies depending on the size and proliferation index, thus close follow-up should be performed. No tumor marker is clearly associated with a poor prognosis. New molecular biology studies are needed in order to find therapeutic targets.

Abbas Khalaf ALI, Mohammed Al-Hilli &amp; Abdullateef Aliasghar: THE ROLE OF COMPUTED TOMOGRAPHY IN THE EVALUATION OF GASTROINTESTINAL STROMAL TUMORS.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the digestive tract and Computed tomography (CT) is an imaging modality of choice for the detection and evaluation of GISTs. This study aimed to describe the computed-tomographic imaging features of gastrointestinal stromal tumors in our clinical work and to evaluate and improve our CT protocols in the diagnosis of GIST. This is a cross-sectional study conducted in the period of October 2011–December 2012 in the Radiology Institute and the GIT Center of Medical City in Baghdad. Twenty cases of GIST were analyzed by multidetector abdominal CT including fifteen male and five female patients of age (20-70) years. Images were analyzed for tumor location, size, definition, diameter, shape and other features. The results showed that 13 (59%) of tumors were located in the stomach and five (23%) were located in the mesentery. GISTs were extraluminal in 13 (59%) patients. The tumor margins of 13 (59%) tumors were well defined, and irregular in eight (36%). Location of GISTs did not correlate with their definition, diameter or shape; while a significant correlation had been found with the hemorrhage and enhancement. In conclusion, CT scan is the most common imaging technique for the detection, localization and initial evaluation of GIST extension. The stomach was the commonest location of GIST occurrence among our patients. The CT features of GISTs were well-defined tumor margins, extraluminal site and fungating morphology.

The true incidence of gastric GIST-a study based on morbidly obese patients undergoing sleeve gastrectomy.

Gastrointestinal stromal tumor (GIST) is a rare neoplasm of the alimentary tract. Previous reports described an incidence of 1 per 100,000. Laparoscopic sleeve gastrectomy (LSG) provides pathological specimens of the majority of the stomach. We examined the pathology from LSG and the incidence and location of GIST. The aim of this study was to study the incidence of asymptomatic GISTs found during LSG at our institution. A search was conducted in a prospectively maintained bariatric registry. Data collected included the following: gender, age, body mass index (BMI), and concomitant hypertension or diabetes mellitus. Histopathology reports were reviewed for incidental GIST. We compared the patients with incidental GIST to the rest of the cohort. Pathology reports of 827 patients that underwent LSG between 2007 and 2014 were reviewed. Five patients had GIST in the resected stomach, an incidence of 0.6 %. The group of patients with GIST had lower BMI and older age compared to the remaining 822 patients. All tumors were located close to the lesser curvature. The incidence of GIST found in this cohort is significantly higher than previously reported. This may be due to an association between these tumors and obesity or because asymptomatic GISTs are underdiagnosed in the general population. These tumors are particularly common in older patients and special attention must be given when performing LSG on this subpopulation. The stomach should be inspected thoroughly before resection. A tumor on the lesser curvature may necessitate changing the surgical plan or aborting the procedure.

Demonstration of gender-specific variability in a pharmacokinetic (PK) analysis of the PERSIST-5 trial of adjuvant imatinib (IM) for patients with primary gastrointestinal stromal tumor (GIST) at significant risk of recurrence.

10538 Background: ThePERSIST-5 phase II trial is evaluating 5 years of adjuvant IM therapy in patients with resected GIST at significant risk of recurrence. This analysis studied the effect of chronic therapy on steady-state trough levels in patients who received IM for up to 24 months to evaluate potential PK variations. Methods: Eligible patients were adults with KIT+ primary GIST who were considered to be at significant risk for recurrence (primary tumor any site ≥2 cm andmitotic rate ≥5/50 high-power fields, or non-gastric primary GIST ≥5 cm) without metastases. R0 resection of primary GIST was performed ≤12 weeks prior to the first IM dose. Patients are to receive oral IM 400 mg/day for up to 5 years or until progression, relapse, or intolerance. Plasma samples for PK analysis were collected at 1, 4, 12, and 24 months. IM plasma concentrations were measured using a validated liquid chromatography-tandem mass spectrometry assay. Results: In-study assay performance (%CV) was ≤9.6% and bias was -1.3% to 5.2%. IM concentrations ranged from below quantifiable limits to 4798 ng/mL. After daily IM doses for up to 12 months (or 24 months in 3 patients), IM trough levels remained constant over time. The range of IM trough levels (mean ± SD) was 957 ± 750 ng/mL to 1219 ± 822 ng/mL at month 1, and 727 ± 430 ng/mL to 996 ± 405 ng/mL at month 12. Inter-patient variability was 40.7-78.4%. There was no significant difference in IM trough levels between months 1 and 4, 1 and 12, or 4 and 12. Trough levels did not significantly differ by location of GIST. Most notably, mean IM trough concentrations were on average ~33% higher in females vs males. Conclusions: In this study,IM trough levels remained relatively unaltered in patients with high-risk GIST who received adjuvant IM for 1 year. The 33% higher mean trough levels in females warrants further study for clinical decision making. Clinical trial information: NCT00867113. [Table: see text]

Laparoscopic endoscopic rendez-vous resection of iuxta-cardial gastric GIST

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract and they often require a surgical removal. Gastrointestinal stromal tumors can originate from any part of the gastrointestinal tract but gastric location is the most common. In the past the risk of rupture of pseudocapsula and peritoneal dissemination have discouraged surgeons from making a minimally invasive surgical treatment. Recently laparoscopic wedge resection has been proposed. Performance of this mini-invasive technique is however difficult in some gastric location of gastrointestinal stromal tumors, such as iuxta-cardial region. The Authors report and discuss a new technique they used to remove a gastrointestinal stromal tumor located just below the cardia, using a rendez-vous endoscopic and laparoscopic technique.

1486PD - Gastrointestinal Stromal Tumors of the Stomach with Kit Exon 9 Mutations Mostly Present with a Favorable Prognosis

ABSTRACT Introduction Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors in the gastrointestinal (GI) tract. Up to 90% of them carry activating mutations in KIT exons 9, 11, 13, or 17 or PDGFRA exons 12, 14 or 18. We were interested whether the aggressiveness in GIST carrying a mutation in KIT exon 9 is influenced by their primary location. Methods We evaluated more than 2000 cases in our GIST and Sarcoma Registry Cologne/Bonn (GSRCB) for GIST with KIT exon 9 mutation. Sequences were analysed by direct Sanger Sequencing. We evaluated pathomorphological and clinical data for KIT exon 9 mutated GIST in different primary locations. Results We could identify 22 gastric, 73 intestinal and 10 rectal GIST carrying a mutation in KIT exon 9. The average tumor diameter in gastric GIST was 4.8 cm (+/- 4.3 cm) whereas small bowel GISTs (n = 62) were measuring 6.6 cm (+/- 3.4 cm) and rectal GISTs (n = 7) 3.9 cm (+/- 2.1 cm). According to the AFIP classification (Miettinen 2006), 16 gastric tumors belonged to the groups of no or low aggressive behavior. Four GISTs were classified as high risk lesions with a mitotic counts of more than 10/50 HPFs and one GIST measuring 11 cm belonged to the moderate risk group. 13 tumors carried the classical 6 base pairs duplication in KIT exon 9 (p.A502_Y503dup). Interestingly, two tumors showed a novel mutation in KIT exon 9 (p.K474_G487del; p.S476I) which have not been described before. In the small intestine, 31 tumors belonged to the high risk, 11 to the moderate and 22 to the low-risk group. In the group of rectal GIST, 6 of 8 cases were high-risk cases. Conclusions KIT exon 9 mutations (typically a 6 bp duplication; p.A502_Y503dup) occur preferentially in a non-gastric location of GISTs. In intestinal cases, this mutational subtype frequently is associated with larger tumors and a high mitotic count, implicating an aggressive behavior. In contrast, gastric tumors with KIT exon 9 mutation more often have a low or no malignant potential. Disclosure All authors have declared no conflicts of interest.

Bone Metastases from Gastrointestinal Stromal Tumor: A Case Report

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Their most common metastatic sites are the liver and the peritoneum, but GISTs rarely metastasize to the bones. We report a case of a 58-year-old man with sternoclavicular joint metastasis from a GIST manifesting 28 months after surgical resection of the small intestine tumor. We will discuss through this paper and a literature review the clinical characteristics, imaging features, and management of this unusual metastatic location of GIST.

EUS-Guided Fine Needle Aspiration of Gastrointestinal Stromal Tumors: The GIST of the Matter

Our understanding of gastrointestinal stromal tumors (GIST) has evolved rapidly over the last few years. GISTs are now considered a distinct entity that arise from the interstitial cells of Cajal and exhibit a variable clinical course. One of the major breakthroughs was the discovery of CD117 antigen expression, also referred to as c-kit, on the tyrosine kinase receptor by GISTs. This antigen can be identified using immunohistochemistry (IHC), is expressed nearly universally by GISTs, and is critical in allowing differentiation of GISTs from myogenic, neurogenic, and other mesenchymal tumors. There has also been a paradigm shift in how the clinical behavior of GISTs is viewed; even though only 10–30% of GISTs are clinically malignant [1], all GISTs are now considered to have malignant potential with long-term follow-up [2]. This shift is based on a number of studies, one of which is a large series from Armed Forces Institute of Pathology (AFIP), where GISTs larger than 2 cm were found to have some finite risk of recurrence [3]. The natural history of smaller GISTs remains unclear at this point, though there have been reports of aggressive behavior in GISTs smaller than 2 cm in size [4]. Specific criteria that include size, mitotic count, and location of GISTs have been described to stratify risk of malignancy and tailor treatment [3, 5]. In this context, an accurate diagnosis, and if possible risk stratification of GISTs, is critical. Towards this end, endoscopic ultrasound (EUS) has become an important tool in our armamentarium. GISTs are typically seen to arise from the fourth layer of the gastric wall. While EUS imaging alone can accurately determine tumor size, wall layer of origin, echogenicity, and tumor margins, it is unable to reliably discriminate GISTs from other subepithelial tumors in all cases [6, 7]. Whether specific endosonographic features alone can help define low-risk and high-risk lesions also remains uncertain [8–10]. Consequently, many experts recommend EUSguided fine needle aspiration (EUS-FNA) for diagnostic sampling of subepithelial lesions when a diagnosis of GIST is being considered. However, in general, gastroenterologists continue to view EUS-FNA for subepithelial lesions with ambiguity. A recent survey of 134 members of the ASGE EUS special interest group found that only 58% believed that EUS combined with FNA was most predictive of a diagnosis of GIST [11]. This notion that EUSFNA is unrevealing in GISTs has been supported by reports of inadequate tissue acquisition with EUS-FNA with yields as low as 33.3% in all specimens [12]. Nevertheless, there is a growing body of more recent literature that has reported steadily improved diagnostic yields of EUS-FNA for GISTs. Watson et al. [13], in the current issue of Digestive Diseases and Sciences, provide additional data regarding the diagnostic yield and performance characteristics of EUS-FNA for GISTs. The authors retrospectively analyzed 65 consecutive patients who underwent EUS-FNA for 66 solid-appearing submucosal upper GI tract lesions over a 4-year period. A resection specimen was available and used as a reference in 28 patients. FNA was performed using either a 22-gauge or 19-gauge needle at the discretion of the endosonographer. A result was deemed diagnostic if a sufficient sample for cytopathologic evaluation and IHC analysis was obtained leading to a specific diagnosis. The authors found EUS-FNA to be diagnostic in 68%, V. Chandrasekhara N. A. Ahmad (&) HUP Division of Gastroenterology, Hospital of University of Pennsylvania, University of Pennsylvania School of Medicine, Ravdin 3 3400 Spruce Street, Philadelphia, PA 19104, USA e-mail: nuzhat.ahmad@uphs.upenn.edu

Laser-supported diaphanoscopy: a new technique in laparoscopic-endoscopic rendezvous procedures allowing better and more tissue-sparing tumor resection than wedge resection

Locating gastrointestinal stromal tumors (GIST) during laparoscopic surgery continues sometimes to be difficult and inaccurate. In addition, the methods used for tumor mapping often do not lead to precise location of tumors. Also, they are too expensive or too complex for an easy surgical approach. Furthermore, the standard wedge resection often sacrifices too much healthy tissue. The current study introduces an innovative tissue-sparing method using laser-supported diaphanoscopy (Endolight) for exact location of GIST during laparoscopic surgery. The instrument was developed by the authors' group. This study retrospectively evaluated two groups of patients experiencing GIST. The first group of 10 patients was treated by standard wedge resection. The second group of 10 patients was treated by Endolight-guided laparoscopic resection during a laparoscopic-endoscopic rendezvous procedure. After precise location of GIST using Endolight, all patients could be successfully resected. The largest resection margins using Endolight (9.8±3.8 mm) were significantly smaller than the largest resection margins using wedge resection (stapler) without Endolight (21.5±9.1 mm; p<0.0001). The average surgery time for the group treated by standard wedge resection was 65 min (range, 28-108 min). The surgery time required for the group treated by Endolight-guided resections ranged from 48 to 189 min (average, 123 min). The number of marks used for Endolight resections ranged from four to seven depending on the location and size of the tumor. The reported technique allows the precise location of GIST, leading to exact and tissue-sparing transmural laparoscopic resection of these tumors compared with standard wedge-resection. Laser-supported diaphanoscopy using the newly developed innovative device offers new perspectives and a highly effective technique for resecting GIST that combines an endoscopic with a laparoscopic approach.

Different Sites and Prognoses of Gastrointestinal Stromal Tumors of the Stomach: Report of 187 Cases

The stomach is the most common site of gastrointestinal stromal tumors (GISTs), but the clinical behavior of gastric GISTs at different sites is unclear. This study was designed to evaluate the clinicopathological (CP) parameters and influence of different gastric sites on outcome in patients with GIST. The CP and follow-up records of 187 patients with GIST who were treated at TianJin Medical University Cancer Institute & Hospital between January 1985 and December 2006 were reviewed. There were 97 men and 90 women (aged 17-88 (median, 56.5) years). CP factors were assessed for overall survival (OS) by using univariate and multivariate analysis. The numbers of cases of upper, middle, and lower third gastric GISTs were 69 (36.9%), 103 (55.1%), and 15 (8%), respectively. Sites of GISTs in the middle or upper stomach, tumor size, intermediate- or high-risk groups, high mitotic count, and low resection status were associated with poor OS (p = 0.041, 0.046, 0.006, 0.000, 0.000, respectively) in a univariate analysis. In a multivariate analysis, tumor location in the upper and middle third of the stomach (p = 0.035), an intermediate or high risk (p = 0.01), and incomplete resection status (p = 0.006) were predictive of poor OS. Patients in intermediate- and high-risk groups had an unfavorable outcome. A complete resection is the most important treatment for survival. The location of GIST in the lower third of the stomach may be a favorable factor, and the significance of different tumor sites for prognosis of gastric GISTs needs to be further clarified.

Laser-supported diaphanoscopy: an innovative technique for locating gastric stromal tumors in gastroscopic-laparoscopic rendezvous: a case series

Development of an innovative method of endoscopic laser-supported diaphanoscopy, for precise demonstration of the location of gastrointestinal stromal tumors (GISTs) at laparoscopy is described. The equipment consists of a light transmission cable with an anchoring system for the gastric mucosa, a connecting system for the light source, and the laser light source itself. During surgery, transillumination by laser is used to show the shape of the tumor. The resection margins are then marked by electric coagulation. Ten patients have been successfully treated using this technique in laparoscopic-endoscopic rendezvous procedures. Average time of surgery was 123 minutes. The time for marking the shape of the tumor averaged 16 minutes. Depending on tumor location and size, 4-7 marks were used, and resection margins were 4-15 mm. This new and effective technique facilitates precise locating of gastric GISTs leading to exact and tissue-sparing transmural laparoscopic resections.

Bilateral gluteal metastases from a misdiagnosed intrapelvic gastrointestinal stromal tumor

BackgroundThe location of gastrointestinal stromal tumors (GIST) outside of the gastrointestinal system is a rare event.Case presentationA 56-year old woman presented with a GIST of the pelvis was misdiagnosed and treated as a uterine leiomyosarcoma. The diagnosis was made after the CD117 (KIT) positivity in the biopsy of the excised bowel mass four years from the first presentation. During this period she presented a bilateral muscle and subcutaneous metastasis in the gluteal area.ConclusionThe correct diagnosis of the extra-gastrointestinal stromal tumor is a challenge even for experienced pathologists. CD117 (KIT) positivity is the most important immunohistochemical feature in the histological diagnosis. To our knowledge a metastatic EGIST (extra-gastrointestinal stromal tumor) to the skeletal muscle bilaterally has not been described previously in the English medical literature.

Multifocal recurrent gastrointestinal stromal tumor of stomach in a pediatric patient associated with ovarian fibroma: Case report and literature review

Gastrointestinal stromal tumors (GISTs) are rare in children. Clinical symptoms include hematemesis, anemia and fatigue. They have malignant potential with unpredictable behavior. They are associated with high risk of local recurrence. Gastric location of GISTs is most commonly associated with other neoplasms. We report a rare case of recurrent gastrointestinal stromal tumor of the stomach associated with benign ovarian fibroma. This casual relationship of this association is unknown and remains to be investigated. Increased awareness of such association is important for early diagnosis and treatment.

Prognostic Stratification of High-risk Gastrointestinal Stromal Tumors in the Era of Targeted Therapy

Recently, a trial of adjuvant imatinib for primary R0-resected intermediate and high-risk gastrointestinal stromal tumors (GISTs) significantly improved recurrence-free survival. But identifying patients having higher chances of recurrence will reduce economic losses and prevent adverse side effects caused by adjuvant treatment. Tissue samples from 93 patients with high-risk GISTs were studied for p16, CD34, and CD44 protein expression and mutations of KIT and PDGFRA gene. Clinicopathologic, immunohistochemical, and mutation results were compared with clinical outcome by univariate and multivariate analyses. KIT mutations were observed in 75 cases (81%) including 46 exon 11 deletion mutations and 31 deletions affecting codons 557-558. A novel 12 bp deletion mutation (KHNG484-488) on KIT exon 9 was detected in a small intestinal GIST. For recurrence-free survival, R0 resection, organ-confined disease stage, and female sex are better prognostic factors in univariate analysis and disease stage was the only factor predicting recurrence (P = 0.02) in multivariate analysis. In overall survival, mutation types, presence of mutation, location of GISTs, and mitosis were significant by univariate analysis. After multivariate analysis, mitotic counts and presence of KIT mutation corresponded to independent prognostic factors. Moreover, mitosis, KIT exon 11 deletion mutation, and deletions affecting exon 557-558 predict recurrence in R0-resected high-risk GISTs (P < 0.05). Prognostic stratification in high-risk GISTs will help identify patients with high-risk GIST who may benefit from adjuvant therapy.