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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The interstitial cells of Cajal complex within the gut wall function as a pacemaker to direct peristalsis. Their neoplastic counterpart is the gastrointestinal pacemaker cell tumor, a spindle and/or epithelioid cell mesenchymal tumor previously known as gastrointestinal stromal tumor or incorrectly called leiomyosarcoma in some cases of older reports. Although numerous cases of gastrointestinal leiomyosarcomas have been documented in the English-language literature, no pediatric case of gastrointestinal stromal tumor or gastrointestinal pacemaker cell tumor has, to our knowledge, been recorded. Herein, we report a case of congenital gastrointestinal pacemaker cell tumor confirmed by immunohistochemistry and electron microscopy in a full-term male newborn.
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PMID:Congenital gastrointestinal pacemaker cell tumor. 1045 37

Gastrointestinal stromal tumor or smooth muscle tumor (GIST) is the designation for a major subset of gastrointestinal mesenchymal tumors that histologically, immunohistochemically, and genetically differ from typical leiomyomas, leiomyosarcomas, and schwannomas. Because GISTs, like the interstitial cells of Cajal, the gastrointestinal pacemaker cells, express CD117 (c-kit protein), the origin of GISTs from the interstitial cells of Cajal has been recently proposed. Comparison of GISTs primary in the omentum and mesentery to GISTs primary in the tubular gastrointestinal tract is of particular diagnostic and histogenetic interest in view of the possible similarity of these tumors with the GIST group. In this study, we analyzed 14 omental and 12 mesenteric primary mesenchymal tumors representing smooth muscle tumors or GISTs. These tumors were phenotypically compared with gastric and small intestinal GISTs, leiomyomas of the esophagus, and leiomyosarcomas of the retroperitoneum. Most (13 of 14) omental and mesenteric (10 of 12) tumors showed histologic features similar to GISTs with elongated spindle cells or epithelioid cells with high cellularity; most of these tumors showed low mitotic activity. Omental and mesenteric GISTs were typically positive for CD117 and less consistently for CD34. They often showed alpha-smooth muscle actin reactivity but were virtually negative for desmin and S-100 protein. One omental and two mesenteric tumors showed features of leiomyosarcoma with ovoid, less elongated nuclei, cytoplasmic eosinophilia; all these tumors had significant mitotic activity. These tumors were positive for alpha-smooth muscle actin and two of them for desmin, but all were negative for CD34 and CD117, similar to retroperitoneal leiomyosarcomas. Tumor-related mortality occurred in the group of mesenteric GISTs, but not in the group of omental GISTs. In contrast, all three patients with a true leiomyosarcoma of the omentum or mesentery had documented liver metastases or died of tumor. In summary, we show that tumors phenotypically identical with GISTs occur as primary tumors in the omentum and mesentery. The occurrence of CD117-positive tumors outside the gastrointestinal tract militates against an origin of these tumors exclusively from the interstitial cells of Cajal.
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PMID:Gastrointestinal stromal tumors/smooth muscle tumors (GISTs) primary in the omentum and mesentery: clinicopathologic and immunohistochemical study of 26 cases. 1047 72

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. Gain-of-function mutations in the juxtamembrane domain of the c-kit gene have been found in several GISTs. In this study, we examined the correlation between the presence of c-kit mutation and prognosis in 124 cases of GIST. DNA samples were extracted from paraffin sections. Exon 11 of the c-kit gene encoding the juxtamembrane domain and exon 17 encoding the kinase domain were amplified by PCR and sequenced. Most GISTs (89%) express the KIT protein, and missense mutations of exon 11 were found in 71 of 124 GISTs (57%). No mutations were detectable in exon 17. These 71 mutation-positive GISTs were larger in size and had more frequently invaded adjacent tissues than did the 53 mutation-negative GISTs. Histologically, the mutation-positive GISTs showed higher mitotic figures and more necrosis and hemorrhage. The patients with mutation-positive GISTs showed more frequent recurrences (P = 0.0005) and higher mortality (P = 0.0001) than did those with mutation-negative GISTs. The c-kit mutation was an independent prognostic factor for overall and cause-specific survival of the patients with GISTs. These results suggest that GISTs may be divided into mutation-positive and -negative subtypes. The prognosis was worse in patients with mutation-positive GISTs than in those with mutation-negative GISTs. Thus, mutation of the c-kit gene may be a good prognostic marker of GISTs.
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PMID:Effect of c-kit mutation on prognosis of gastrointestinal stromal tumors. 1048 75

Gastrointestinal stromal tumor (GIST) is the preferred term for mesenchymal tumors specific for the gastrointestinal tract (60% in stomach, 30% small intestine, 10% elsewhere). GISTs include most tumors previously designated as leiomyoma, cellular leiomyoma, leiomyoblastoma, and leiomyosarcoma. However, in the esophagus, leiomyoma is the most common mesenchymal tumor. GISTs are composed of spindle (70%) or epithelioid (30%) cells, and 10%-30% are malignant showing intra-abdominal spread or liver metastases. They are immunohistochemically positive for c-kit (CD117), CD34, and sometimes for actin but are almost always negative for desmin and S100-protein. The malignant GISTs especially show activating mutations in the c-kit gene. GISTs and gastrointestinal autonomic nerve tumors (GANT) overlap. The cell of origin is not fully understood, but resemblance to the interstitial cells of Cajal, expression of some smooth muscle markers, and occurrence outside of the GI-tract suggest origin from multipotential cells that can differentiate into Cajal and smooth muscle cells.
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PMID:Gastrointestinal stromal tumors: recent advances in understanding of their biology. 1053 70

Most GIST have traditionally been classified as submucosal origin by upper gastrointestinal series (UGIS) or endoscopy. However, we experienced a gastrointestinal mesenchymal origin tumor expressed by polypoid mass with a long stalk. The gastric outlet was obstructed by the polypoid mass on the duodenum. The microscopic findings of the resected mass showed a stromal cell component by immunohistochemical stain. We experienced gastric stromal tumor found as a polypoid mass with long stalk which was easily detected by endoscopy. It would not have been suspected as a stromal tumor as a result of endoscopic findings only.
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PMID:Gastric malignant stromal tumor with long stalk impacted into duodenum. 1056 65

Two cases of synovial sarcoma that arose in the upper digestive tract are reported. One case was a polypoid mass that arose at the gastroesophageal junction; the other was a large intramural mass that arose in the wall of the stomach. Both cases had a classic biphasic pattern. In the stomach tumor, the biphasic morphology was focal and there was an abrupt transition to poorly differentiated synovial sarcoma. The tumors had immunohistochemical features that were consistent with synovial sarcoma. Ultrastructural evaluation of the gastroesophageal tumor supported the diagnosis. The diagnostic X;18 translocation was demonstrated by fluorescence in situ hybridization on sections from paraffin-embedded tissue in 86% and 50% of interphase nuclei from the gastroesophageal and gastric tumor, respectively. The translocation was present in equal frequency in the epithelial and spindle cells in the biphasic areas and the poorly differentiated areas of the gastric tumor, indicating that the development of the more aggressive subclone was probably due to genetic mutations not encompassing the SYT-SSX gene fusion product. We are aware of only five reported cases of synovial sarcoma arising in the digestive tract, all in the proximal esophagus. These cases are the first reported arising in the gastroesophageal junction and stomach and the only cases of synovial sarcoma of the digestive tract in which the diagnostic translocation was demonstrated. Sarcomatoid carcinoma (carcinosarcoma) and gastrointestinal stromal tumor are the main differential diagnoses for synovial sarcoma in this site. Synovial sarcoma of the digestive tract may be underdiagnosed, and its recognition may have important clinical implications. Fluorescence in situ hybridization is helpful in making this distinction.
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PMID:Synovial sarcoma of the upper digestive tract: a report of two cases with demonstration of the X;18 translocation by fluorescence in situ hybridization. 1065 12

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the GI tract, and expresses KIT and CD34 in most cases. Gain-of-function mutation of the c-kit proto-oncogene has been described, but its significance in GIST has not yet been fully evaluated. Mutation in exon 11 of the c-kit gene was determined by both polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and direct sequencing in primary and metastatic GISTs and esophageal leiomyomas in Japanese subjects. C-kit gene mutation was identified in 15 of 48 primary GISTs (31%), four of seven metastatic GISTs, but none of the leiomyomas. Three mutations were mis-sense point mutations, and 16 were in-frame deletions of 3-48 bp. C-kit gene mutation was observed equally in low- and high-risk groups, and was not related to any clinical and pathologic factors, phenotypes or Ki-67 labeling index (LI) of tumor cells. In five of 15 deletion mutations (four in primary tumors and one in a metastatic tumor), the mutations were present at the distal location of exon 11 of the c-kit gene, which was a minor mutation in previous reports from Finland and the USA. C-kit gene mutations in GIST are not always related to a poor prognosis, but further comparative studies are necessary in Western and Japanese populations.
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PMID:C-kit gene abnormalities in gastrointestinal stromal tumors (tumors of interstitial cells of Cajal. 1066 49

Although rare elsewhere in the gastrointestinal tract, leiomyomas (LMs) are the most common esophageal mesenchymal neoplasms. In contrast, gastrointestinal stromal tumors (GISTs) predominate in the stomach and intestines but have not been documented in the esophagus. This study was undertaken to determine the clinicopathologic features and frequency of esophageal GISTs compared with LMs and leiomyosarcomas (LMSs) of the esophagus. A total of 68 stromal/smooth muscle tumors from the Armed Forces Institute of Pathology and the Haartman Institute of University of Helsinki were reclassified by current histologic and immunohistochemical criteria. There were 17 GISTs, 48 LMs, and three LMSs. The esophageal GISTs occurred in 12 men and five women with a median age of 63 years (range, 49-75 years). All tumors were from the lowest third of the esophagus, and the most common complaint was dysphagia, whereas two tumors were detected incidentally. Histologically the tumors had an overall basophilic appearance and showed combinations of solid, myxoid, and perivascular collarlike patterns with a spindle cell histology in 13 patients and epithelioid histology in four patients. All tumors were positive for CD117 and for CD34, whereas two patients were also positive for alpha-smooth muscle actin (SMA) and three patients were positive for desmin. One patient showed a unique immunophenotype with coexpression of CD117, CD34, SMA, and desmin. Nine patients died of disease, including all who had a tumor larger than 10 cm, and also one patient whose tumor showed five mitoses per 50 high-power fields. In comparison, esophageal LMs (n = 48) occurred in a younger population (median age, 35 years) but, similar to the GIST group, men predominated (67%). All LMs were clinically indolent tumors with no tumor-related mortality. The LMs showed eosinophilic cytoplasm, and were positive for desmin and SMA, and negative for CD117 and CD34. All three LMSs were large high-grade tumors that showed muscle cell markers but no CD117. All patients died of disease. Esophageal GISTs showed mutations in exon 11 of c-kit as described previously in gastric and intestinal GISTs. The separation of GISTs from esophageal LMs is important diagnostically because the former group has a high risk of malignant behavior.
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PMID:Esophageal stromal tumors: a clinicopathologic, immunohistochemical, and molecular genetic study of 17 cases and comparison with esophageal leiomyomas and leiomyosarcomas. 1068 Aug 89

Gastrointestinal stromal tumors (GIST) represent an extremely rare group of tumors, which are mostly of smooth muscle origin like leiomyomas, leiomyosarcomas and leiomyoblastomas. With the introduction of immunohistochemical analysis an epithelioid and an autonomic nerve variant can be distinguished. The purpose of this review is to demonstrate the image morphological appearance of these rare tumors together with the pathology based upon a retrospective analysis of five of our own cases since 1997. There are no pathognomonic imaging findings for characterizing a gastrointestinal stromal tumor; however, it should be included in the differential diagnosis if one or multiple large, round or oval, well-delineated gastrointestinal tumors occur in combination with central necrosis. Carney's syndrome is characterized by the syndromal association of a gastrointestinal stromal tumor (originally: gastric leiomyosarcoma) with an extra-adrenal paraganglioma and a pulmonary chondroma. In this rare syndrome, the radiological approach is important to diagnose or rule out the--simultaneous or consecutive--appearance of at least two of the three tumor entities (GIST, extra-adrenal paraganglioma, pulmonary chondroma).
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PMID:[Radiology of gastrointestinal stromal tumors (GIST) and a case of Carney syndrome]. 1077 62

In a 55-year-old man, a tumor about 3 cm in diameter was detected in the upper abdomen by abdominal ultrasound screening during follow-up of chronic hepatitis C discovered in 1990. There were no symptoms and no abnormalities on physical examination. Tests for tumor markers were negative. By barium meal and gastroscopy, submucosal tumor was found on the lesser curvature of the stomach, with bridging fold in the absence of central ulceration. Biopsy revealed no tumor tissue. Under the diagnosis of submucosal tumor of the stomach, either a leiomyoma or leiomyosarcoma, partial resection of stomach was performed. Direct invasion of the surrounding organs, lymph node metastasis or distant metastasis was not observed grossly in the operation. Histologic examination of the resected specimen revealed proliferation of spindle cells and oval cells in an interlacing pattern. Immunohistochemistry for CD34, vimentin and c-kit protein was strongly positive, while smooth muscle actin, S-100 protein, desmin and p53 protein were negative. The proliferating cell nuclear antigen index was about 50%, while the MIB-1 index was < or = 1%. From these findings, this tumor was diagnosed as a gastrointestinal stromal tumor of the uncommitted type.
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PMID:A case of gastrointestinal stromal tumor of the stomach. 1081 97


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