Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10721 (c-kit)
 6,575 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gain-of-function c-kit gene mutations and immunoreactivity of the c-kit protein CD117 in many gastrointestinal stromal tumors (GISTs) seem to support the idea that GISTs form a biologically distinct entity. In this study, the clinicopathologic features of 171 cases of GIST at a single institution were investigated for accurate diagnosis, and their relative risk for mortality was estimated by multivariate analysis. A GIST was defined diagnostically as a mesenchymal spindle or epithelioid cell lesion arising in the wall of the gastrointestinal tract with consistent immunoreactivity for CD117. The 171 patients with GISTs comprised 96 males (56.1%) and 75 females (43.9%), with a mean age of 59.4 years. One hundred and forty-five tumors (84.8%) occurred in the stomach, 18 (10.5%) in the small intestine, 6 (3.5%) in the rectum, and 2 (1.2%) in the esophagus. The median tumor size was 4.5 cm (range, 1.2 to 38 cm). Spindle-cell GISTs were present in 132 cases (77.2%); mixed GISTs, in 25 cases (14.6%); and epithelioid GISTs, in 14 cases (8.2%). Ten cases (55.6%) of spindled small intestine GIST contained eosinophilic skeinoid fibers. Immunoreactivity for CD34, h-caldesmon, alpha-smooth-muscle actin (SMA), desmin, and S-100 was observed in 156 (91.2%), 131 (76.6%), 46 (26.9%), 7 (4.1%), and 14 (8.2%) tumors, respectively. The percentage of CD34 positivity (38.8%) was low, in contrast with the high percentage of reactivity for SMA (77.8%) and S-100 (44.4%) in small intestine GISTs. By our histologic grading system using tumor differentiation, MIB-1 score, and necrosis, 129 tumors (75.4%) were classified as low grade and 42 tumors (24.6%) were classified as high grade. With a median follow-up period of 83.5 months for 122 living patients, the 5-year and 10-year survival rates were 81.7% and 67.4%, respectively. Multivariate analysis showed that both tumor size >10 cm and high grade were significantly associated with a poor outcome. As a result, GISTs >10 cm or high grade, 5 to 10 cm and low grade, and < or =5 cm and low grade were regarded as high risk, intermediate risk, and low risk for mortality, respectively. In conclusion, it is important to recognize GISTs that have a specific molecular pathogenesis and to separate them from other mesenchymal tumors with optimal immunostaining for CD117 when making a diagnosis and prognostic classification based on tumor size and MIB-1 grade.
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PMID:Gastrointestinal stromal tumor: consistent CD117 immunostaining for diagnosis, and prognostic classification based on tumor size and MIB-1 grade. 1215 68

Gastrointestinal stromal tumors (GISTs) are a heterogeneous group of mesenchymal tumors with a wide spectrum of histologic features and consistent expression of c-Kit. We describe an 85-year-old woman who presented with left lower quadrant abdominal pain and was subsequently diagnosed as having a malignant GIST. The tumor was composed of short fascicles of spindle cells. In addition to the presence of tumor giant cells, the tumor also demonstrated many osteoclast-like giant cells, a feature that has not been previously described in the literature. These giant cells expressed histiocytic markers CD68 and alpha(1)-antitrypsin but not c-Kit, a marker for GISTs. Electron microscopy showed no features of smooth muscle differentiation in the giant cells. The possible origin of the osteoclast-like giant cells is discussed in the context of immunohistochemical and ultrastructural characteristics.
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PMID:A malignant gastrointestinal stromal tumor with osteoclast-like giant cells. 1217 99

Gastrointestinal stromal tumor (GIST), a stromal tumor of the gastrointestinal tract defined as CD117 (c-kit)-positive neoplasm, occurs primarily in adults. GIST with CD117 (c-kit) mutation and certain cytogenetic abnormalities is associated with malignancy, though a definite relationship between prognosis and molecular alterations remains to be elucidated. We report the cytologic features of an epithelioid GIST arising in the stomach of a child and metastatic to the liver, and the molecular mutational analysis of both the primary gastric tumor and the liver metastasis. Literature of pediatric GISTs was also reviewed. Fine needle aspiration of the liver metastasis, processed by Ultrafast Papanicolaou stain, showed fragments of cohesive small epithelioid cells with bland oval nuclei and unipolar cytoplasm transected by capillaries. Immunohistochemically, all nodules in the stomach and liver expressed CD117 (c-kit). Interestingly, some of the gastric tumor clusters were uniformly CD34 positive, whereas others were uniformly CD34 negative, suggesting heterogeneity of tumor clones. The presence of neurosecretory granules further subtyped the tumor into gastric autonomic nerve tumor (GANT). Molecular mutational analysis, performed in both the gastric tumor and the liver metastasis, showed no sequence abnormality in exons 9, 11, and 13 of CD117 (c-kit). Cytogenetic study revealed normal karyotype. These features might suggest a different molecular mechanism leading to malignancy in certain GISTs arising in children.
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PMID:Epithelioid gastrointestinal stromal tumor of the stomach with liver metastases in a 12-year-old girl: aspiration cytology and molecular study. 1265 41

Primary malignant tumors of the small intestine are rare. Malignant gastrointestinal stromal tumors are the third most common neoplasm among primary malignant small bowel tumors. A 56-year-old woman was admitted to our hospital because of appetite loss and dyspnea with movement. On admission, physical examination revealed severe anemia in her conjunctiva and a tumor in her left abdomen. Her hemoglobin level was 6.2 g/dL and other laboratory data were normal. Abdominal ultrasonograms and computed tomograms revealed a 55 x 70-mm heterogeneous mass and multiple low-density masses in the liver. Superior mesenteric arteriograms revealed a hypervascular tumor fed by the jejunal arteries. A malignant gastrointestinal stromal tumor arising from the jejunum with liver metastases was suspected. Partial resection of the affected jejunum and left trisegmentectomy of the liver were performed. The resected primary tumor was 120 x 45 x 65 mm. The tumor was mainly submucosal, but extended outside the jejunum; it was elastically firm and multiloculated. A small ulcer was seen on the mucosal side. The metastatic liver tumors were solid or cystic with diameters of 20 to 40 mm. Histopathological examination revealed that the tumors were characterized by fascicular proliferation of spindle-shaped cells. Immunohistochemical staining was positive for CD34 and c-kit, and negative for S-100 protein and smooth muscle actin. This case was a malignant gastrointestinal stromal tumor originating in the jejunum with liver metastases. The primary tumor and liver metastases were successfully resected simultaneously.
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PMID:Malignant gastrointestinal stromal tumor of the jejunum with liver metastasis. 1223 33

An 85-year-old woman was admitted to our hospital because of vomiting. An upper gastrointestinal series what showed a large esophageal hiatus hernia, suggesting an association with extrinsic pressure in the middle portion of the stomach. An upper gastrointestinal endoscopic examination showed severe esophagitis and a prominent narrowing in the middle portion of the stomach, however, it showed normal gastric mucosa findings. CT and MRI revealed a large tumor extending from the region of the lower chest to the upper abdomen. From these findings, the tumor was diagnosed as gastrointestinal stromal tumor (GIST), which arose from the gastric wall and complicated with an esophageal hiatus hernia. We performed a laparotomy, however, the tumor showed severe invasion to the circumferential organs. Therefore, we abandoned the excision of the tumor. Histologically, the tumor was composed of spindle shaped cells with marked nuclear atypia and prominent mitosis. The tumor cells were strongly positive for CD34 and c-kit by immunohistochemical examination. From these findings, the tumor was definitely diagnosed as a malignant GIST. As palliative treatment, we implanted a self-expandable metallic stent in the narrow segment of the stomach. The patient could eat solid food and was discharged. In the treatment of esophageal hiatus hernia, the rare association of GIST should be considered.
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PMID:Giant gastrointestinal stromal tumor, associated with esophageal hiatus hernia. 1232 9

Gastrointestinal stromal tumor (GIST) is a quite common gastrointestinal mesenchymal tumor entity that has been recently established by pathologists. The prediction of the biologic behavior of GISTs is relatively difficult. Recently, classifications of the biologic behavior of GISTs according to metastatic potential (low risk, intermediate, high risk) have been proposed. The gain-of function mutation of c-kit proto-oncogene has been detected in GISTs and its role in molecular pathogenesis of GIST has been established. Imatinib mesylate (formerly STI 571, Glivec, Novartis Pharmaceuticals Corp, Switzerland) inhibits the tyrosin-kinase activity of KIT receptor, and clinical trials for GIST are in progress. In the past, no effective drug was known for the treatment of GISTs. Recently, the effectiveness of Imatinib mesylate in patients bearing metastatic GISTs has been reported. The treatment and prognosis of GIST will change significantly in the coming few years, as the clinical application of Imatinib mesylate becomes more common. In the near future, the value of Imatinib mesylate as a post-operative adjuvant chemotherapy for patients with GISTs without metastasis should be studied, and the way to classify GISTs according to biologic behavior will become quite important.
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PMID:[Recent progress in gastrointestinal stromal tumor (GIST)]. 1235 34

Although separating gastrointestinal stromal tumor (GIST) from mesenteric fibromatosis and sclerosing mesenteritis is clinically important, this distinction sometimes poses problems for practicing pathologists. In the STI571 (Gleevec, Imatinib) era, the problem may be further compounded when protocol-driven staining for CD117 (c-kit) is performed on spindle cell proliferations presenting in the bowel wall and mesentery using an antibody known to react with the majority of mesenteric fibromatoses when other antibodies are more specific. Because most mesenteric fibromatoses have mutations in the pathway and hence have abnormal nuclear accumulation of beta-catenin protein, we studied beta-catenin expression among a panel of other immunohistochemical stains to distinguish mesenteric fibromatosis, GIST, and sclerosing mesenteritis. Examples of gastrointestinal stromal tumors (GIST, 11), sclerosing mesenteritis (5), and mesenteric fibromatosis (10) were retrieved from the archives of our institutions. Cases were studied with an immunohistochemical panel consisting of CD117, beta-catenin, CD34, smooth muscle actin, desmin, keratin, and S-100 protein. Cases were scored as "negative," "focally positive," or "diffusely positive." In evaluating beta-catenin, nuclear accumulation was required. GIST all had CD117 (11 of 11, diffuse) and CD34 (11 of 11, diffuse) with variable actin (5 of 11, focal) and negative desmin, keratin, S-100 protein. All GIST lacked beta-catenin (0 of 11). Mesenteric fibromatosis had CD117 (6 of 10, 3 focal, 3 diffuse), typically expressed more weakly than in GIST, actin (5 of 9, focal), and desmin (3 of 8, focal) in keeping with myofibroblastic differentiation but lacked CD34, S-100, and keratin. CD117 staining was not eliminated by use of a non-avidin-biotin technique. Nuclear beta-catenin was detected in 9 of 10 fibromatoses, including one case associated with familial adenomatous polyposis. Two of five sclerosing mesenteritis cases focally expressed CD117. None of the sclerosing mesenteritis cases had nuclear beta-catenin. Sclerosing mesenteritis cases were otherwise fibroblastic and myofibroblastic with focal actin in 5 of 5 and negative desmin, keratin, and S-100 protein but one had CD34 (1 of 5, focal). With increasing protocol-driven interest in evaluating bowel wall and mesenteric spindle cell lesions using CD117 (c-kit) antibodies, it is important for practicing pathologists to be aware that lesions other than GISTs are likely to express this antigen using certain antibodies. beta-Catenin staining identifies lesions that are, instead, mesenteric fibromatoses.
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PMID:Beta-catenin immunohistochemistry separates mesenteric fibromatosis from gastrointestinal stromal tumor and sclerosing mesenteritis. 1236 44

Endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNA) is considered to be a reliable and accurate method for the evaluation of submucosal lesions in the gastrointestinal tract. Herein, we report our experience with the diagnosis of 10 cases of gastrointestinal stromal tumor (GIST) using EUS-FNA. The materials obtained from the EUS-FNA were stained with the rapid Romanowsky or the Papanicolaou method for cytologic examination. The subsequent surgical resection specimens were submitted for histopathologic examination. Immunoperoxidase stains were performed on the cell blocks and/or representative histologic sections of the tumor using commercially available antibodies against c-kit (CD117), CD34, S-100, and smooth muscle actin. Of the 10 cases studied, there were five men and five women with an average age of 62 years (range, 38 to 87 years). Five tumors were located in the stomach, and five in the duodenum. Tumor size ranged from 3.5 to 16.2 cm. Immediate on-site evaluation and cytologic diagnoses were given in eight cases (80%) with an average of three passes. The diagnoses were confirmed by strong and diffuse tumor cell c-kit immunoreactivity in the cell blocks. However, the final diagnoses of two other cases (20%) were not established until surgical resections were obtained. Retrospectively, reviews of cytologic smears of both cases demonstrated rare cohesive sheets or clusters of spindle cells with cigar-shaped nuclei. These observations were initially misinterpreted as benign fibrous tissue and/or fragments of smooth muscle of the gastrointestinal wall such as one might encounter in a routine transgastric or transduodenal EUS-FNA. The current study showed that when combining cytologic and immunocytochemical studies, EUS-FNA is accurate and efficient in the diagnosis of GIST. It exemplified the importance of considering GIST in the differential diagnosis of gastrointestinal lesions and also demonstrated the potential pitfalls of EUS-FNA evaluation of submucosal lesions in the gastrointestinal tract.
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PMID:Diagnosis of gastrointestinal stromal tumor by endoscopic ultrasound-guided fine needle aspiration biopsy--a potential pitfall. 1237 22

Gastrointestinal stromal tumors (GISTs) are non differentiated sarcoma of the gastrointestinal tract and have for a long time been confused with well differentiated tumors and classified as leiomyosarcoma. These tumors are characterized immunohistochemically by CD 117 staining. This marker represents the expression of c-kit which is a receptor for growth factor with enzymatic activity (tyrosine kinase). Recent studies have found that an inhibitor of specific tyrosine kinase is effective in the treatment of GIST with an estimated response rate of more than 60%. This new drug could significantly improve the prognosis of these aggressive chemoresistant tumors.
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PMID:[At last, an effective therapy for non-differentiated GI sarcomas (gastro intestinal stromal tumor)]. 1241 Jan 26

Gastrointestinal stromal tumor (GIST) is the designation for a major subset of gastrointestinal mesenchymal tumors that histologically, immunocytochemically, and genetically differ from leiomyomas, leiomyosarcomas, and schwannomas. GISTs derive from the interstitial cells of Cajal and, in addition to variable expression of smooth muscle and neural markers, they characteristically express CD34 and CD117. The cytological appearance, including immunocytochemical and mutational analysis of c-kit gene in primary GIST has been well described. To our knowledge, only two cases of metastatic GIST diagnosed by fine-needle aspiration (FNA) have been reported. We illustrate three cases of metastatic GIST in the liver. Two cases had no prior history of gastrointestinal tumor and the third case had a 4-yr previous history of duodenal tumor. Consistent immunocytochemistry and ultrastructual studies supported the diagnosis of GIST. We emphasize that in the appropriate clinical and radiological setting, a confident diagnosis of GIST can be established by FNA of metastatic lesions.
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PMID:Fine-needle aspiration cytology diagnosis of metastatic gastrointestinal stromal tumor in the liver: a report of three cases. 1241 97


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