BACKGROUND & OBJECTIVE: Mesenchymal TUMOR of the GASTROINTESTINAL tract comprises a diverse group of neoplasms which occurs in adults. With recognition of immunohistochemical profile in recent years, GASTROINTESTINAL STROMAL TUMOR ((GIST)) has been grouped separately from other sarcomas. No therapeutic modality except. Surgey has ever demonstrated definitive evidence of clinical benefit in (GIST). These TUMORs occur most commonly in the stomach, followed by small intestine, and are rare in the colon and rectum and extremely rare in the esophagus. (GIST) also arises rarely in the omentum, mesentery and peritoneum.CASE: A 69-year-old male was admitted to surgical ward with clinical and CT scan findings of large, movable abdominal mass behind the stomach with probable origin from the pancreas. Explorative laparatomy revealed an 18 x 16 cm mass in lesser omentum. Pathological and immunohistochemical techniques revealed malignant (GIST).CONCLUSION: GASTROINTESTINAL STROMAL TUMOR should be considered in the differential diagnosis of the abdominal mass.

The GASTROINTESTINAL STROMAL TUMOR ((GIST)) is a rare mesenchymal TUMOR of GASTROINTESTINAL (GI) tract. This TUMOR has tendency to liver metastasis and peritoneal recurrence, however; the primarily lymph node involvement or metastasis is rare. Here we reported a 17-years-old girl with multifocal gastric (GIST) and multiple lymph node involvement at presentation and recurrence in celiac lymph nodes. We also review some case reports on lymph node metastasis in (GIST).

Gasterointestinal STROMAL TUMOR ((GIST)) is a mesenchimal TUMOR. Mostly originate from stomach however small intestine, esophagus, colon, and rectum are another sits of TUMOR growth. Rarely it originate in extra intestinal sites such as the omentum, mesenteries, or retro peritoneum. They are often asymptomatic and are detected as an incidental finding or after evaluation of nonspecific symptoms .However this TUMOR can present as a palpable abdominal mass, with abdominal pain and or GASTROINTESTINAL bleeding. In this manuscript we represent a patient with (GIST) of the stomach mesentery.

Background: A past history of sporadic solid cancers is disclosed in 10% of GASTROINTESTINAL STROMAL TUMOR ((GIST)) patients. Simultaneous occurrence with other malignancies is encountered in 14 to 16%, but the synchronous occurrence of (GIST) and hepatocellular carcinoma (HCC) has been reported only once in the English literature.Case: A 62-year-old male patient presented for evaluation of cirrhosis and suspected HCC in view of raised AFP. On the FDG PET-triphasic CT, done for staging workup, a non-FDG avid area was noted in segment 4 which was hypervascular on the arterial phase with a corresponding wash out. Abutting the lesser curvature of stomach, another non-FDG avid exophytic polypoidal mass with heterogeneous hypervascular enhancement was noted.Results: A non FDG avid exophytic hypervascular enhancing mass arising from the lesser curvature of stomach was suggested to be (GIST) with possible diagnostic considerations for the non FDG avid arterial phase enhancing focal lesion in segment IV of liver included hypervascular metastatic deposit / De novo HCC. Endoscopic/ histopathological correlation was advised which confirmed the omental lesion to be (GIST) and liver lesion to be HCC.Conclusion: Patient coming for HCC staging in whom a synchronous exophytic hypervascular omental (GIST), adjacent to the lesser curvature of the stomach was incidentally discovered, is a rare case of simultaneous two primaries involving the (GIST) and HCC.

Introduction: The most common connective tissue neoplasm of the GASTROINTESTINAL tract is GASTROINTESTINAL STROMAL TUMORs ((GIST)s). Its presentations are usually abdominal pain and GASTROINTESTINAL bleeding. Case Presentation: We report a 31-year-old man with abdominal pain presented to our hospital with 10 days history of abdominal pain. After radiologic investigations, total distended stomach paraesophageal hernia and antral deformity were seen in the CT scan. Subsequently, the patient underwent surgery and after releasing the stomach, a large sealed perforated mass was seen in the antrum near the diaphragmatic hiatus and small localized abscess that subtotal gastrectomy and hernia repair was done. Pathologic examination revealed that the perforated mass is a (GIST). Conclusions: We report a rare complication of (GIST) that is perforation and the first report of simultaneous paraesophageal hernia and perforated (GIST).

Introduction: GASTROINTESTINAL STROMAL TUMOR ((GIST)) is a rare mesenchymal TUMOR of the GASTROINTESTINAL (GI) tract that usually occurs in the stomach and the small intestine, respectively. This TUMOR often occurs in people over the age of 40 years, especially in the fifth and sixth decades of life. The range of symptoms varies from asymptomatic to symptomatic depending on the size and location of the TUMOR. The standard diagnostic of this TUMOR is the pathological examination of tissue specimens. Also today, the main treatment for this TUMOR is surgery and resection of the TUMOR. Case Report: A 43-year-old woman presented with melena and a decrease in hemoglobin level to 4. The patient underwent upper and lower GI endoscopy, CT angiography, and EUS, which was reported a vascular lesion below the ampulla of vater. After laparotomy and Whipple procedure, pathology reported TUMOR as (GIST). The patient was discharged from the hospital in good general condition. Conclusion: we suggest that patients presented with GASTROINTESTINAL bleeding and the presence of a lesion in the diagnostic modalities, (GIST) should always be considered as a differential diagnosis.

A gas trointes tinal s tromal TUMOR ((GIST)) is the mos t common intramural mesenchymal TUMOR of the gas trointes tinal tract. Their metas tasis to extragas trointes tinal organs is rare, especially the spleen. The patient was a 52-year-old man who, with the diagnosis of peritonitis, underwent laparotomy emergently. At the time of surgery, an extensive TUMOR was seen in the s tomach, esophagus, and jejunum, which had metas tases to the spleen. Total gas trectomy, esophagojejunos tomy, and splenectomy were performed. The morphological s tudies showed a spindle-cell type of (GIST) that were positive for CD117 and Discovered on (GIST)-1 (DOG1). (GIST) was diagnosed as high-risk and treated with imatinib. In follow-up, he died 5 months after discharge. Here, we reported a case of (GIST) synchronous with splenic metas tasis. Surgeons mus t alert for possible metas tases associated with (GIST)s, clinical presentation, diagnosis, treatment, and pathological classification.

Background & Aim: GASTROINTESTINAL STROMAL TUMORs ((GIST)s) are the most common mesenchymal TUMORs of GASTROINTESTINAL tract. They are known to express c-kit, which is important in their diagnosis and treatment. The aim of our study was to assess the morphologic and immunohistochemical features of GASTROINTESTINAL STROMAL TUMORs and the significance of c-kit expression in them.Materials and Methods: The study was descriptive and simple method for sampling was used. Files from pathology laboratory of National Iranian Blood Transfusion Organization were searched for cases referred as (GIST) between April 2002 and April 2005. Clinical data were recorded and their H&E and IHC slides studied. The results were analyzed by SPSS 10 software.Results: C-kit expression is a key confirmatory marker for (GIST) diagnosis. Therefore out of 31 referred cases only 22 cases of (GIST)s (12 males, 10 females) were included in this study. The patient's median age was 51 years. (GIST)s most frequently occurred in the stomach (12 cases) followed by small intestine (9 cases) and colon (1 case). The size of TUMORs ranged from 2.5 to 15 cm. Also 72.7% of TUMORs were hypercellular. Benign spindle cell TUMORs were 31%, malignant spindle cell TUMORs 23%, benign epithelioid TUMORs 23% and malignant epithelioid TUMORs constituted 23%. Mucosal invasion and TUMORal necrosis were present in 22.7% and 27% of cases, respectively: 72.8% of TUMORs had mitotic activity exceeding 5 per 50 hpf. The expression of other IHC markers were: Vimentin 63.1%, Desmin 13.1%, Smooth muscle actin 22.7%, S-100 protein 22.7% and CD34 63.6%.Conclusion: With regard to the crucial role of c-kit in the pathogenesis of (GIST)s, c-kit expression is essential for their diagnosis and therapy; therefore, TUMORs which are negative for c-kit, especially those with spindle fascicles, most probably are other mesenchymal neoplasms such as leiomyomas, schwannomas, etc., and should be classified according to their IHC markers. Long-term follow up of all (GIST)s patients is recommended.

GASTROINTESTINAL STROMAL TUMORs ((GIST)) are the usual primary mesenchymal neoplasms of the GI tract. Interstitial cells of Cajal (ICCs) are intestinal pacemaker cells that instigate peristalsis in the stomach and intestine, and are measured to be precursors of (GIST). We are reporting a 17 year old boy with chronic constipation since childhood and a huge rectum in abdominal radiography, who underwent exploratory laparotomy, resection of huge rectum and construction of sigmoid colostomy. Pathology report was "Hyperplasia of Interstitial Cells of Cajal".