If you have a gastrointestinal stromal tumor or are close to someone who does, knowing what to expect can help you cope. Here you can find out all about. Most common mesenchymal tumor of gastrointestinal tract; arises from or is differentiated towards interstitial cell of Cajal, involved in gut. Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. They account for ~5% of all sarcomas.
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Fistulizing Gastric GIST
Gastrointestinal stromal tumors GISTs are the most common mesenchymal neoplasms of the gastrointestinal tract. GISTs arise in the smooth muscle pacemaker interstitial cell of Cajalor similar cells. GIST was introduced as a diagnostic term in Histopathologists were unable to specifically distinguish between types we now know to be dissimilar molecularly. Subsequently, CD34and later CD were identified as markers that could distinguish the various types.
Due to the change in definition, clinical pathways of care before the year are largely uninformative in the current era. GISTs may present gastdico trouble swallowinggastrointestinal bleedingor metastases mainly in the liver. Intestinal obstruction is rare, due to the tumor’s outward pattern of growth. Often, there is a history of vague abdominal pain or discomfort, and the tumor has become rather large by time the diagnosis is made.
Tumores del estroma gastrointestinal (GIST): serie del Hospital Central de la Defensa Gómez Ulla
GISTs are tumors of connective tissuei. Small tumors are generally benign, especially when cell division rate is slow, but large tumors disseminate to the liveromentum and peritoneal cavity. They rarely occur in other abdominal organs. GISTs are thought to arise from interstitial cells of Cajal ICCthat are normally part of the autonomic nervous system of the intestine.
Most GISTs are sporadic. The c-KIT molecule comprises a long extracellular domaina transmembrane segmentand an intracellular part. Mutations generally occur in the DNA encoding the intracellular part exon 11which acts as a tyrosine kinase to activate other enzymes.
Mutations make c-KITfunction independent of activation by scfleading to a high cell division rate and possibly genomic instability. Most GIST cells with wildtype i. CT scanning is often undertaken see the radiology section. The definitive diagnosis is made with a biopsywhich can be obtained endoscopicallypercutaneously with CT or ultrasound guidance or at the time of surgery. A biopsy sample will be investigated under the microscope by a pathologist physician. Smaller tumors can usually be confined to the muscularis propria layer of the intestinal wall.
Large ones grow, mainly outward, from the bowel wall until the point where they outstrip their blood supply and necrose die on the inside, forming a cavity that may eventually come to communicate with the bowel lumen.
When GIST is suspected—as opposed to other causes for similar tumors—the pathologist can use immunohistochemistry specific antibodies that stain the molecule CD [also known as c-kit ] —see below.
Gastrointestinal stromal tumor – Wikipedia
Other cells that show CD positivity are mast cells. The purpose of radiologic imaging is to locate the lesion, evaluate for signs of invasion and detect metastasis.
Features gisy GIST vary depending on tumor size and organ of origin. Larger tumors usually cause symptoms in contrast to those found incidentally which tend to be smaller and have better prognosis. Plain radiographs are not very helpful in the evaluation of GISTs. If an abnormality is seen, it will be an indirect sign due to the tumor mass effect on adjacent organs. On abdominal x-raystomach GISTs may appear as a radiopaque mass altering the shape of the gastric air shadow.
Intestinal GISTs may displace loops of bowel and larger tumors may obstruct the bowel and films will show an obstructive pattern. If cavitations are present, plain radiographs will show collections of air within the tumor. Barium fluoroscopic examinations and CT are commonly gasrrico to evaluate the patient with abdominal complaints. Even in cases when the barium swallow is abnormal, an MRI or CT scan must follow since it is impossible to vastrico abdominal cavities and other abdominal organs with a barium swallow alone.
Intravenous contrast material is needed to evaluate lesion vascularity. CT advantages include its ability to demonstrate evidence of nearby organ invasion, ascites, and metastases. The ability of MRI to produce images in multiple planes is helpful in determining the bowel as the gastico of origin which is difficult when the tumor is very largefacilitating diagnosis. Since GISTs arise from the bowel layer called muscularis propria which is deeper to the mucosa and submucosa from a luminal perspectivesmall GIST imaging usually suggest a submucosal process or a mass within the bowel wall.
In barium swallow studies, these Gatrico most commonly present with smooth borders forming right or obtuse angles with the nearby bowel wall, as seen with any other intramural mass. Ulcerations fill with barium causing a bull’s eye or target lesion appearance. Ggastrico contrast-enhanced CTsmall GISTs are seen as smooth, sharply defined intramural masses with homogeneous attenuation. If the tumor outstrips gkst blood supply, it can necrose internally, creating a central fluid-filled cavity with bleeding and cavitations that can eventually ulcerate and communicate into the lumen of the bowel.
In giat case, barium swallow may show an air, air-fluid levels or oral contrast media accumulation within these areas.
In contrast enhanced CT images, large GISTs appear as heterogeneous masses due to areas of living tumor cells surrounding bleeding, necrosis or cysts, which is radiographically seen as a peripheral enhancement pattern with a low attenuation center. Areas of bleeding within the tumor will vary its signal intensity depending on how long ago the bleeding occurred. The solid portions of the tumor are typically low signal intensity on T1-weighted imagesare high signal intensity on T2-weighted images and enhance after administration of gadolinium.
Signal-intensity voids are present if there is gas within areas of necrotic tumor. Malignancy is characterized by local invasion and metastases, usually to the liveromentum and peritoneum.
However, cases of metastases to bone, pleuralungs and retroperitoneum have been seen. In localized, resectable adult GISTs, if anatomically and physiologically feasible, surgery is the primary treatment of choice. Laparoscopic surgery, a minimally invasive abdominal surgery using telescopes and specialized instruments, has been shown to be effective for removal of these tumors without needing large incisions. The decision of appropriate laparoscopic surgery is affected by tumor size, location, and growth pattern.
Radiotherapy has not historically been effective for GISTs : Imatinib has been used in selected neoadjuvant settings. For example, rectal GIST often requires radical surgery to achieve complete resection, involving abdominoperineal resection and permanent stoma.
In these situations, the use of neoadjuvant imatinib can significantly decrease both tumour size and mitotic activity, and permit less radical sphincter-preserving surgery. A substantial proportion of GIST tumors have a high risk of recurrence as estimated by a number of validated risk stratification schemes, and can be considered for adjuvant therapy.
Following surgical resection of GISTs, adjuvant treatment with imatinib reduces the risk of disease recurrence in higher risk groups. If resistance to imatinib is encountered, the multiple tyrosine kinase inhibitor sunitinib marketed as Sutent can be considered. The effectiveness of imatinib and sunitinib depend on the genotype. GISTs occur in per one million people.
Gastrointestinal stromal tumor
The true incidence might be higher, as novel laboratory methods are much more sensitive in diagnosing GISTs. The majority of GISTs present at ages 50—70 years.
Gaetrico most of the age spectrum, the incidence of GIST is similar in men gasrtico women. Adult GISTs are rare before age Pediatric GISTs giet considered to be biologically distinct. Although the generally accepted definition of pediatric GIST is a tumor that is diagnosed at the age of 18 years or younger,  “pediatric-type” GISTs can be seen in adults, which affects risk assessment, the role of lymph node resection, and choice of therapy.
From Wikipedia, the free encyclopedia. Gastrointestinal stromal tumor Histopathologic image of gastrointestinal stromal tumor of the stomach.
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Cholangiocarcinoma Klatskin tumor gallbladder: Adenocarcinoma Pancreatic gastricp carcinoma cystic neoplasms: Serous microcystic adenoma Intraductal papillary mucinous neoplasm Mucinous cystic neoplasm Solid pseudopapillary neoplasm Pancreatoblastoma.
Primary peritoneal carcinoma Peritoneal mesothelioma Desmoplastic small round cell tumor.
Cell surface receptor deficiencies. PTH1R Jansen’s metaphyseal chondrodysplasia. CASR Familial hypocalciuric hypercalcemia.
FZD4 Familial exudative vitreoretinopathy 1. Type I cytokine receptor: Retrieved from ” https: Views Read Edit View history. In other projects Wikimedia Commons. This page was last edited on gaetrico Augustat