Findings Of Gastrointestinal Stromal Tumors Research Articles

An Unexpected Finding of Gastrointestinal Stromal Tumors During Laparoscopic Sleeve Gastrectomy; How to Deal? How Much Safety Margin Needed?

Background: There is an increasing incidence of coincidental gastric gastrointestinal stromal tumors (GIST) during a laparoscopic sleeve gastrectomy (LSG). Resection with negative margin R0 is the safest and most proper treatment. Objectives: The incidence of GIST in patients undergoing LSG and resection with a 1- to 2-cm safety margin was validated and analyzed. The primary endpoint is that can simultaneous excision be oncologically adequate or not? How much GIST is supposed to be far from a staple line? Methods: The present prospective study included 338 patients with body mass index (BMI) ≥ 35. All patients underwent LSG without known history or imaging reveal GIST. Resection was done with a safety margin of 1 to 2 cm away from the stapled margin and, then, sent for histopathology and immunohistochemically staining. Results: A total of 17 patients (5%) had coincidental GIST. The size was T1 in 88.2% of patients; 16 patients were staged as IA according to the American Joint Committee on Cancer (AJCC TNM). Safety margin was ≤ 1 cm for 3 patients to avoid incorporation in staple line and 14 patients (82.3%) had 2 cm safety margin. Resection margin in biopsy revealed positive resection margin R1 for 2 patients, whose safety margin was only 1 cm or less. A total of 15 patients had a negative margin (R0), whose safety margin was 2 cm. Conclusions: Any incidental GIST can be removed safely during LSG as long as it is far from the staple line with at least a 2-cm safety margin and negative resection margins without changing the procedure. Margins less than 1 cm are associated with adverse prognostic factors.

A surprise visitor at cesarean section: Gastrointestinal stromal tumor of the uterus

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors that almost always arise from the GI tract and account for 0.1-3% of GI tumors. During pregnancy, GIST is highly unusual given the predilection of this tumor to appear in the fifth to seventh decade of life. The finding of GISTs outside the GI tract is also rare as the cell of origin of these tumors is believed to be the interstitial cell of Cajal, found only in the GI tract. Extra intestinal GISTs have been reported with a few cases arising from the uterus or metastatic to the ovary; however; an asymptomatic uterine GIST occurring at pregnancy as an incidental finding during cesarean section has not been reported so far. We present a 32-year-old lady who underwent an emergency caesarean section and was found to have a GIST of the uterus. The tumor was excised in toto and she started imatinib therapy postoperatively. At the end of three years of close follow-up, she has done well with no evidence of recurrence.

Effectiveness of radiological findings of gastrointestinal stromal tumors in the prediction of high-risk potential for malignancy: comparison of the NIH and AFIP criteria

Effectiveness of radiological findings of gastrointestinal stromal tumors in the prediction of high-risk potential for malignancy: comparison of the NIH and AFIP criteria

A5223 - Unexpected finding of gastrointestinal stromal tumors during laparoscopic bariatric surgery

A5223 - Unexpected finding of gastrointestinal stromal tumors during laparoscopic bariatric surgery

Incidental Finding of Gastrointestinal Stromal Tumors during Laparoscopic Sleeve Gastrectomy in Obese Patients.

The frequency of incidental pathology found during laparoscopic bariatric surgery has been estimated to be 2%. Gastrointestinal stromal tumors (GISTs) are infrequent lesions and account for less than 1% of all digestive tract tumors. The reported incidence of this type of tumors during bariatric surgery is around 0.8%. The objective of this study was to evaluate incidence, characteristics, and evolution of incidentally found GISTs in patients undergoing laparoscopic sleeve gastrectomy (LSG) for the treatment of obesity. A retrospective analysis from a prospectively collected database was conducted. Demographic data, clinical data, laboratory tests, preoperative esophagogastroduodenoscopy (EGD), postoperative pathology report from surgical specimen with tumor markers, and patient's outcomes were evaluated. From June 2006 to January 2014, 915 patients underwent LSG at our institution. Five (0.5%) patients were found to have incidental GIST. There were four (80%) women; average age was 59.6±6.3years (range 46-63). None of them had symptoms that served as orientation for preoperative diagnosis. EGD findings were non-suggestive of this pathology in any of these cases. Superficial chronic gastritis was the most common finding in the endoscopic biopsy (60%). All the tumors found in the surgical specimen were of low or very low risk of malignancy, with less than 5 mitoses per 50 fields, less than 2cm in diameter, and disease-free surgical margins. Cluster of differentiation (CD) 117 and CD 34 were positive in 100% of the cases. None of the patients required adjuvant therapy after the surgery. At 5-year follow-up, all patients were asymptomatic and disease free. The incidence of unsuspected GIST in LSG specimens in our series was low and similar to what has been reported. The lack of symptoms and the preoperative EGD findings were not suggestive of this diagnosis in any case. The degree of tumor malignancy was low in all patients and LSG was the definitive treatment, without recurrence at 5-year follow-up.

The investigation of incidence and radiological findings of gastrointestinal stromal tumor as a rare cause of abdominal mass

Aim: The aim of the present study was to evaluate the investigation of incidence and radiological findings of gastrointestinal stromal tumors (GIST) as a rare cause of abdominal mass, with current literature review. Material and Methods: Between February 2011 and May 2016, a total of 4,443 patients who underwent abdominal multislice computed tomography and magnetic resonance imaging due to the clinical indications for abdominal pain, abdominal swellingmass were analyzed in our hospital. The retrospective cross-sectional study included forty-five patients, who were subsequently diagnosed with GIST histopathologically. Results: GIST was identified in 45 (1%) patients. Of the total 45 patients, 21 (47%) were men and 24 (53%) were female. The mean age was 55 years, ranging from 35 to 73 years. As a result of radiological examinations, the tumor location was stomach in 22 cases (49%), small intestine in 12 cases (27%) and colon in 9 cases (20%). The retroperitoneal localization was also found in 2 cases (4%). The average size of the lesions ranged between 2 and 15 cm. Malignant degeneration and omental metastasis were seen in 11 (24%) and 7 cases (16%) respectively. Conclusion: GIST is a rare cause of abdominal mass with an incidence of 1% in our region. They are most commonly localized in the stomach, rarely in the omentum/mesentery and retroperitoneum. The Malignant transformation is not frequent. Diagnosis and evaluations of mass can be made successfully by radiological imaging modalities.

A Review of Sleeve Gastrectomy Specimen Histopathology

With the increasing popularity of sleeve gastrectomy, many stomach specimens are being evaluated. Understanding the significance and treatment for unexpected pathology is important. This study examines the incidence of relevant histopathology of sleeve gastrectomy specimens. It evaluates previous data for each histopathology and provides recommendations for treatment. In this study, a retrospective review was performed for 241 patients who underwent sleeve gastrectomy from 2009 to 2014 at a single institution. Of the specimens, 122 had no significant histopathology, 91 had gastritis, 13 had lymphoid aggregates, 5 had hyperplasia, 3 had intestinal metaplasia, 3 had gastrointestinal stromal tumors (GISTs), and 3 had gastric polyps. Of the GISTs all had a low mitotic rate and the size of the tumor ranged from 1.5 to 4.5 cm. The findings of metaplasia may be a marker for increased risk of malignancy and may require additional surveillance. The findings of GIST may warrant interval imaging to survey for recurrence, though the likelihood of recurrence for the tumors in this study is less than 2 per cent based on previous studies.

Correlation between Computed Tomography and Pathological Findings of Gastrointestinal Stromal Tumors Treated with Imatinib Mesylate

Correlation between Computed Tomography and Pathological Findings of Gastrointestinal Stromal Tumors Treated with Imatinib Mesylate

CT Findings of Gastrointestinal Stromal Tumor in Meckel’s Diverticulum - a Case Report

Although the small bowel constitutes about 75% of the gastrointestinal (GI) tract, primary tumors in it are relatively rare, making up only a small percentage of all GI neoplasms. Neoplasms of Meckel's diverticulum are rare and gastrointestinal stromal tumors are very uncommon malignant tumors occurring in this site. We report a case of a small-bowel tumor with an extremely rare histological type and uncommon location which was diagnosed on 64 MDCT scan and subsequently confirmed at surgery and histopathology. A 46-year-old male nonsmoker and nondiabetic presented to the emergency department with 3 massive gastrointestinal bleeding episodes in the form of melena. On examination, the patient was apyrexial and was having tachycardia and pallor with a blood pressure of 80/30mmHg. He had no past history of hematemesis or melena. The patient was resuscitated by 6 fresh blood transfusions and underwent abdominal x-ray and ultrasonography which were unremarkable. In 24 hours, the patient underwent three EGDs which failed to reveal any cause of bleeding from upper gut. Next day, colonoscopy was done which showed colon smeared with altered blood; however, no mucosal abnormality was visualized up to the ileocecal valve. In addition, however, blood was seen pouring out through the ileocecal valve and about 10cm of terminal ileum were filled with blood. No mucosal lesion was seen. On the second day in evening, the patient again had two massive bleeding episodes, again went into shock and four more blood transfusions were given to combat shock. The patient was send to the department of radiodiagnosis for CT scan which was done by Siemens Somotom Sensation 64 Multislice CT and showed a highly enhancing pelvic mass, exophytic, projecting from the small-gut wall, likely arising from a Meckel’s diverticulum (figures 1, 2 and 3). Figure 1 Figure 1: Axial MDCT image showing an exophytic, briskly enhancing pelvic mass arising eccentrically from the small gut. CT Findings of Gastrointestinal Stromal Tumor in Meckel’s Diverticulum a Case Report

Tumor do estroma gastrintestinal: achados clínicos, radiológicos e anatomopatológicos

OBJETIVO: Investigar e descrever os achados clínicos, radiológicos e anatomopatológicos dos tumores do estroma gastrintestinal. MATERIAIS E MÉTODOS: De dezembro de 2000 a março de 2006, 16 pacientes foram operados por tumores do estroma gastrintestinal em nossa instituição. As variáveis analisadas foram sexo e idade dos pacientes, sinais e sintomas na consulta inicial, localização e tamanho do tumor, achados radiológicos, características anatomopatológicas e a ocorrência de metástases. RESULTADOS: A população em estudo constou de nove homens e sete mulheres. Os locais de origem dos tumores primários foram o estômago (n = 5), o reto (n = 4), o intestino delgado (n = 3), o mesentério (n = 3) e o cólon sigmóide (n = 1). Tomografia computadorizada foi o principal método radiológico empregado. Massa circunscrita, de contornos lobulados e que sofre realce heterogêneo pelo meio de contraste foi o principal achado por imagem. Em nosso estudo, nove pacientes (56% dos casos) apresentaram metástases ao diagnóstico ou recorrência do tumor num período médio de dois anos e oito meses. CONCLUSÃO: O tumor do estroma gastrintestinal acomete adultos de meia-idade e idosos e deve ser lembrado no diagnóstico diferencial das massas abdominais. Diagnóstico precoce, tratamento correto e acompanhamento rigoroso são fundamentais, pois, como demonstrado em nosso trabalho, essas neoplasias apresentam alta tendência à malignidade.

Correlation of Computed Tomography and Positron Emission Tomography in Patients With Metastatic Gastrointestinal Stromal Tumor Treated at a Single Institution With Imatinib Mesylate: Proposal of New Computed Tomography Response Criteria

Response Evaluation Criteria in Solid Tumors (RECIST) are insensitive in evaluating gastrointestinal stromal tumors (GISTs) treated with imatinib. This study evaluates whether computed tomography (CT) findings of GIST after imatinib treatment correlate with tumor responses by [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) and develops reliable, quantitative, CT response criteria. A total of 172 lesions selected by RECIST were evaluated in 40 patients with metastatic GISTs treated with imatinib. All patients had pretreatment and 2-month follow-up CTs and FDG-PETs. Multivariate analysis was performed using tumor size and density (Hounsfield unit [HU]) on CT and maximum standardized uptake value (SUVmax) on FDG-PET. Patients were observed up to 28 months. Mean baseline tumor size and density on CT were 5.3 cm and 72.8 HU, respectively, and mean baseline SUVmax on FDG-PET was 5.8. Thirty-three patients had good response on FDG-PET. A decrease in tumor size of more than 10% or a decrease in tumor density of more than 15% on CT had a sensitivity of 97% and a specificity of 100% in identifying PET responders versus 52% and 100% by RECIST. Good responders on CT at 2 months had significantly longer time to progression than those who did not respond (P = .01). Small changes in tumor size or density on CT are sensitive and specific methods of assessing the response of GISTs. If the prognostic value of our proposed CT response criteria can be confirmed prospectively, the criteria should be employed in future studies of patients with GIST.

PKCθ expression in gastrointestinal stromal tumor

Gastrointestinal stromal tumor is characterized by a gain of function mutation of KIT gene and the expression of c-kit protein, but in 5% of cases, c-kit expression is negative although histological findings of gastrointestinal stromal tumor are most suspicious. The existence of c-kit-negative gastrointestinal stromal tumors points to the need of additional markers for making the diagnosis. In this study, we studied the expression of PKCθ and correlated their expression with other immunohistochemical profiles of gastrointestinal stromal tumors and evaluated their usability as a diagnostic marker. For this purpose, 220 gastrointestinal stromal tumors were immunohistochemically stained for PKCθ, c-kit, CD34, α-smooth muscle actin and S-100 protein. Additionally, genetic studies of KIT and PDGFRA genes were performed using c-kit-negative or PKCθ-negative cases. All the 220 masses were either PKCθ-positive or c-kit-positive. PKCθ was positive in 212 (96%) cases and c-kit was positive in 216 (98%) cases in the cytoplasm of tumor cells with a diffuse staining pattern. Out of 212 PKCθ-positive GISTs, 208 (98%) cases were c-kit-positive, 174 (82%) cases were CD34-positive, 62 (29%) cases were SMA-positive and S-100 protein was positive in 54 cases (26%). Genetic analyses on eight PKCθ-negative cases showed exon 11 mutations of KIT gene in four cases. Two PKCθ-positive and c-kit-negative GISTs showed mutations of PDGFRA gene. Our study shows that PKCθ is a useful marker and it may play a role in the development of gastrointestinal stromal tumors. Together with c-kit, PKCθ immunostaining can be used as an important diagnostic tool in the pathologic diagnosis of gastrointestinal stromal tumors with its high specificity and sensitivity.

Incidental Finding of Gastrointestinal Stromal Tumors (GISTs) during Laparoscopic Gastric Bypass

Gastrointestinal stromal tumors (GISTs) are rare tumors, accounting for <1% of all neoplasms of the alimentary tract. GISTs have not been previously reported in association with gastric bypass surgery. This study is a retrospective review of 517 consecutive morbidly obese patients who underwent laparoscopic Roux-en-Y gastric bypass (LRYGBP) between January 2002 and August 2005. Incidental intraoperative findings of gastric GIST were recorded. 4 patients (0.8%) were noted to have GISTs intra-operatively upon inspection of the stomach prior to partition. All GISTs were identified along the anterior aspect of the upper third of the stomach and were removed by laparoscopic wedge excision with at least a 1 cm margin. The 4 tumors were <1 cm in size and all had immunohistochemical analysis positive for CD117 (c-kit). None of the tumors had determinants of malignant behavior (high mitotic rate, necrosis or pleomorphism). We have found a 0.8% incidence of gastric GISTs in our morbidly obese patients undergoing LRYGBP. All of these small, benign tumors were found incidentally in asymptomatic patients. This case series underscores the need to fully assess the stomach prior to gastric pouch formation. Without the ability to grossly determine the benign or malignant behavior of GISTs, all these tumors found incidentally should be resected with adequate margins.

Clinicopathologic Study of Gastric Submucosal Tumor: Endosonographic and Immunohistochemical Findings of Gastrointestinal Stromal Tumors (GISTs) in Stomach

Clinicopathologic Study of Gastric Submucosal Tumor: Endosonographic and Immunohistochemical Findings of Gastrointestinal Stromal Tumors (GISTs) in Stomach Bong Min Ko, Su Jin Hong, Kye Won Kwon, Chang Beom Ryu, Joo Young Cho, Joon Seong Lee, Moon Sung Lee, Chan Sup Shim, Boo Sung Kim BACKGROUND/AIM: The gastrointestinal stromal tumors (GIST) constitute the largest catergory of primary non-epithelial neoplasm of the gastrointestinal tract and include most tumors previously designated as leiomyomas/leiomyosarcomas. Clinically and pathologically, GIST represents a spectrum of tumors that include benign and malignant variants. A small proportion of tumors apparently lacking mitotic activity do metastasis. This study was performed to evaluate the need of follow up and treatment of GISTs. METHOD: This study was performed on 38 patients who had gastric submucosal tumor on endoscopy and endosonography (EUS) and confirmed by histologic examinations using immunohistochemistry between January 2001 and October 2003 at our hospital. We evaluated the clinical features, EUS findings (size, layer, echogenicity, cystic change, lobuation, marginal halo, echogenic foci) and immunohistochemical stain (CD117, CD34, SMA, S-100, Ki-67). RESULT: 1) 14 of the 38 patients in gastric submucosal tumors were diagnosed GIST. 2) The age of the patients with GIST ranged from 37 to 86 years old, with an average age of 58.3 years. 3) In GIST, lobulation on EUS findings was correlated with risk of aggressive behavior in GISTs significantly (<0.05). 4) Ki-67 was correlated with risk of aggressive behavior in GISTs significantly (<0.05). 5) GISTs appeared as hypoechoic mass arising from 2nd, 3rd and 4th layer. CONCLUSION: EUS and histologic diagnosis including immunohistochemical stain approach should be performed to differentiate diagnosis when showed gastric SMT. Although GISTs has low malignant potential, regular follow up or resection is needed. *T1650 Endoscopic and Echoendoscopic Evaluation of Gastric Varices Eradication with Cianoacrilate Erika Macedo, Fernanda Thuler, Veruska Di Sena, Gustavo De Paulo, Frank Nakao, Jose Ardengh, Angelo P. Ferrari Jr. Introduction: bleeding from gastric varices rupture is more severe than from esophageal varices. Usual endoscopic techniques (sclerotherapy and banding) are not good choices for gastric varices eradication. Cianoacrilate endoscopic injection has been reported as the best choice for such patients. Aim: to asses the value of echoendoscopy in monitoring gastric varices eradication by cianoacrilate injection. Method: 17 patients with Sarin type GEV2 varices were submitted to endoscopic injection of a cianoacrilate and lipiodol solution (1 ml each). Patients younger than 18 years and/or with severe systemic disease were excluded from the study. All patients were submitted to EUS and endoscopy before and at 3, 6 and 12 months after index treatment. Doppler signal was used during EUS. After each 3-month interval the injection was repeated if there was endoscopic evidence of remaining or recurrent varices. Results: our study group consisted of 10 men and 7 women, mean age 50.6 years (range 22 76, median 51 years). Portal hypertension was secondary to cirrhosis due to schistosomiasis (4), chronic B or C viral hepatitis (3 and 8) and alcohol abuse (2). Endoscopic injection was successfully performed in the U turn position, with no immediate complications. Three patients are still waiting for the first 3-month re-evaluation and two patients died of hepatic insufficiency, unrelated to bleeding. Among the remaining 12 patients, 8 finished the study (1 year follow-up), 4 had their 3and 6month follow-up (2 in each group). In seven patients there was a need for additional injection sessions: a mean of 1.8 sessions/patient (range 1-3). Endoscopic follow up showed complete eradication of variceal novel in every patient. EUS follow up showed absence of variceal flow (negative Doppler signal) in every patient considered eradicated by conventional endoscopy. There were no complications. Conclusion: endoscopic injection of cianoacrilate plus lipiodol is a safe and effective method for gastric varices eradication. EUS evaluation allows detection of variceal flow andmay help in planning additional treatment as well as in monitoring the patient.