Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inflammatory myofibroblastic tumor (IMT) is an uncommon mesenchymal neoplasm with a variable histologic appearance that may mimic other spindle cell processes, particularly nodular fasciitis, desmoid tumor, and in intra-abdominal locations, gastrointestinal stromal tumor. Recently, gene fusions involving ALK at chromosome 2p23 have been described in IMTs. The resultant ALK protein overexpression in the myofibroblastic component of these tumors is detectable by immunohistochemistry. We examined 73 IMTs, 20 cases of nodular fasciitis, 15 desmoid fibromatoses, and 15 gastrointestinal stromal tumors by immunohistochemistry using ALK-11, a rabbit polyclonal antibody that recognizes the C-terminus of the protein. ALK positivity was detected in 44 of 73 (60%) IMTs. All cases of nodular fasciitis, desmoid fibromatosis, and gastrointestinal stromal tumors were ALK negative (p < 0.001). These findings demonstrate that ALK positivity is common in IMTs, and immunohistochemistry using anti-ALK antibodies can be helpful in the differential diagnosis of these neoplasms. In addition, anti-ALK staining seems to correlate with those IMTs that have the typical tri-patterned histologic appearance and clinical presentation, providing additional support to the premise that IMT is a distinctive clinicopathologic entity within the broad category of inflammatory pseudotumors.
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PMID:Anaplastic lymphoma kinase (ALK) expression in the inflammatory myofibroblastic tumor: a comparative immunohistochemical study. 1168 52

Gastrointestinal stromal tumors (GISTs), the specific KIT-positive mesenchymal tumors of the gastrointestinal tract, have been sporadically reported in the rectum, but there are few clinicopathologic series. In this study we analyzed the clinicopathologic features of 133 anorectal GISTs, 3 intramural leiomyomas (LMs), and 8 leiomyosarcomas (LMSs) from the files of the Armed Forces Institute of Pathology and the Haartman Institute of the University of Helsinki. Ninety-six GISTs were documented as KIT-positive and three additional ones as CD34-positive. Thirty-four tumors were included by their histologic similarity to KIT- or CD34-positive cases. GIST-specific c-kit gene mutations, mostly in exon 11, were documented in 18 of 29 cases (62%). The GISTs occurred in adults with the age range of 17-90 years (median 60 years) with a significant male predominance (71%). The tumors ranged from small asymptomatic intramural nodules to large masses that bulged into pelvis causing pain, rectal bleeding, or obstruction. They were mostly highly cellular spindle cell tumors; four tumors had an epithelioid morphology. The tumors coexpressed CD34 and KIT and were rarely positive for smooth muscle actin or desmin and never for S-100 protein. Seventy percent of patients with tumors >5 cm with more than 5 mitoses/50 high power fields (HPF) (n = 31) died of disease, whereas only one tumor <2 cm with <5 mitoses/50 HPF (n = 21) recurred and none caused death. Long latency was common between primary operation and recurrences and metastases; either one occurred in 60 of 111 patients with follow-up (54%). Distant metastases were in the liver, bones, and lungs. Three benign actin- and desmin-positive and KIT-negative intramural LMs, similar to those seen in the esophagus, were identified. There were eight LMSs, six of which formed a polypoid intraluminal mass and were actin-positive and KIT-negative. Despite high mitotic counts, only one LMS patient died of disease. A great majority of rectal smooth muscle and stromal tumors are GISTs, which have a spectrum from minimal indolent tumors to overt sarcomas. Intramural LMs are exceptional, and true LMSs are rare, and similar to colonic ones, often present as intraluminal polypoid masses that appear to have a better prognosis than GISTs with similar mitotic rates.
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PMID:Gastrointestinal stromal tumors, intramural leiomyomas, and leiomyosarcomas in the rectum and anus: a clinicopathologic, immunohistochemical, and molecular genetic study of 144 cases. 1168 71

In the present study, we reviewed 73 Chinese cases of gastrointestinal stromal tumor (GIST), and analyzed factors in evaluating malignant potential, in particular focusing on Ki-67 index and p53 expression to determine whether these can be used as prognostic indicators in GIST. The p53 positive rate was 50.7% and it was significantly higher in malignant (25/35; 71.43%) than in benign cases (13/38; 34.21%). A Ki-67 labeling index of >10% was also significantly different between malignant (23/35; 65.71%) and benign cases (14/38; 36.84%). In the cases in which the patient died, 15/21 and 14/21 cases showed expression of p53 and Ki-67, respectively; both had a higher expression than in surviving cases. Comparing the cases positive for both Ki-67 and p53 with those positive for Ki-67 or p53 alone, and those negative for both Ki-67 and p53, the latter demonstrated the best prognosis. The study also indicated that the malignant potential of GIST is correlated with the mitotic index (> or =1/10 high-power fields; HPF), tumor size (> or =5 cm), high cellularity, tumor invasive growth, tumor location, tumor hemorrhage and tumor necrosis.
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PMID:Gastrointestinal stromal tumors: clinicopathological study of Chinese cases. 1169 73

Involvement of the inferior vena cava (IVC) by hepatic tumors, although uncommon, is considered to be unresectable by standard surgical techniques. Recent advances in hepatic surgery have made combined hepatic and vena caval resection possible. The purpose of this study is to describe the surgical techniques and early results of combined resection of the liver and IVC. From 1997 to 2000, 11 patients underwent resection of the IVC along with four to seven liver segments. Resections were carried out for hepatocellular carcinoma (four); colorectal metastases (four); and hepatoblastoma, gastrointestinal stromal tumor metastases, and squamous cell carcinoma in one patient each. Ex vivo procedures were performed twice, and total vascular isolation was used in the nine other cases. The IVC was reconstructed with ringed Gore-Tex tube graft (five), primarily (five), or with Gore-Tex patches (one). There were two early deaths: one from liver failure at 3 weeks and one from sepsis secondary to a perforated segment of small bowel 4 months postresection. One patient with a gastrointestinal stromal tumor died at 32 months of recurrent tumor and one patient with hepatocellular carcinoma is alive with recurrent tumor at 16 months. The remaining patients are alive and disease free with follow-up ranging from 3 to 40 months without evidence of IVC occlusion. Combined resection of the liver and IVC is a formidable undertaking with substantial surgical risk. However, this aggressive surgical approach offers a chance for cure in patients with tumors involving the IVC that would otherwise have a dismal prognosis.
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PMID:Resection of the inferior vena cava for hepatic malignancy. 1173 Feb 25

Gastrointestinal stromal tumor (GIST) is an uncommon tumor, which was usually diagnosed by endoscopic biopsy or surgical resection. This study evaluated the efficacy and accuracy of endoscopic ultrasound (EUS) -guided fine-needle aspiration (FNA) biopsy in the diagnosis of GIST and reported its cytomorphologic features. Twelve patients with gastric GIST were diagnosed through EUS-guided FNA. Immediate on-site evaluation and cytologic diagnoses were given in nine cases (75.0%) with an average of three passes. Cell blocks provided diagnostic material in three cases (25.0%). Spindle cells were present in the cytologic material in all cases. Two patients had subsequent surgical resections. Immunohistochemical (IHC) studies performed in cell blocks and two surgical specimens all supported the original diagnoses. In the two cases with surgical resections, IHC results in cell blocks were similar to that in the resected specimens. This study demonstrated that when combining smears and cell blocks, EUS-guided FNA is accurate and efficient in the diagnosis of GIST. IHC reactivity in cell blocks correlated with that of the main tumors.
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PMID:Cytologic diagnosis of gastrointestinal stromal tumors of the stomach by endoscopic ultrasound-guided fine-needle aspiration biopsy: cytomorphologic and immunohistochemical study of 12 cases. 1174 29

Gastrointestinal stromal tumors (GISTs), the most common mesenchymal tumors of the digestive tract, are believed to arise from the interstitial cells of Cajal. GISTs are characterized by mutations in the proto-oncogene KIT that lead to constitutive activation of its tyrosine kinase activity. The tyrosine kinase inhibitor STI571, active against the BCR-ABL fusion protein in chronic myeloid leukemia, was recently shown to be highly effective in GISTs. We used 13,826-element cDNA microarrays to define the expression patterns of 13 KIT mutation-positive GISTs and compared them with the expression profiles of a group of spindle cell tumors from locations outside the gastrointestinal tract. Our results showed a remarkably distinct and uniform expression profile for all of the GISTs. In particular, hierarchical clustering of a subset of 113 cDNAs placed all of the GIST samples into one branch, with a Pearson correlation >0.91. This homogeneity suggests that the molecular pathogenesis of a GIST results from expansion of a clone that has acquired an activating mutation in KIT without the extreme genetic instability found in the common epithelial cancers. The results provide insight into the histogenesis of GIST and the clinical behavior of this therapeutically responsive tumor.
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PMID:Gastrointestinal stromal tumors with KIT mutations exhibit a remarkably homogeneous gene expression profile. 1175 74

Gastrointestinal autonomic nerve (GAN) tumor is an uncommon specialized form of gastrointestinal stromal tumor (GIST). We report the case of a 46-year-old man affected by this tumor. The neoplasm arose from the sigmoid colon. The patient underwent surgery but eight months later an omental relapse occurred. A second laparotomy was successfully performed and the patient is free of disease at 21 months of follow-up. To our knowledge this is the first case of a large bowel GAN tumor described in the literature.
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PMID:Gastrointestinal autonomic nerve tumor: case report and review of the literature. 1176 90

42 gastrointestinal mesenchymal tumors are analyzed by the authors with characterization of immunohistochemistry and DNA study. Out of 42 tumors, 29 GIST 3 leiomyoma, 4 leiomyosarcoma, 3 benign schwannoma, 1 soliter fibrous tumor, 1 inflammatory myofibroblastic tumor and 1 benign haemangiopericytoma were found. All 29 GIST but two could be characterized by c-kit (CD-117) and CD-34 positivity independently weather they displayed focal neurogenic and/or myogenic immunomarkers. In GIST group, 10 cases were benign, 6 borderline and 13 malignant. All benign cases were euploid by DNA study, the malignant tumours were highly aneuploid. Concerning the borderline GIST group by morphology, the aneuploid DNA content may speak for malignant biological behavior, and the diploid DNA content in low grade malignant GIST by morphology may speak for better outcome in the malignant group. There is a discussion about the nomenclature of this morphological group, about the role of the c-kit gene and the necessity of the immunohistochemistry and DNA content determination.
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PMID:[Gastrointestinal stromal tumors. Observations on the basis of 29 cases]. 1177 55

Gastrointestinal stromal (pacemaker cell) tumors (GIST/GIPACTs) are frequently associated with activating KIT mutations, primarily of exon 11 and rarely of exons 9 and 13, as well as certain chromosome rearrangements. Reports regarding the frequency and prognostic significance of KIT mutations are conflicting and few cases have been completely sequenced. Furthermore, there are few detailed analyses of chromosome alterations in GIST/GIPACTs. In a detailed analysis of 14 GIST/GIPACTs from 12 patients, we found a wider spectrum of KIT mutations than previously reported, including 11 different in-frame mutations involving exons 11, 14, and 15. No mutations were detected in four malignant tumors. The shorter (GNNK-) KIT isoform was preferentially expressed. Cytogenetic and spectral karyotype analyses of 10 tumors revealed clonal abnormalities in eight tumors; the most common were terminal 1p deletions and losses of chromosomes 14 and/or 22. Neither KIT mutation status nor chromosome aberrations correlated with tumor phenotype or clinical behavior in our series. Collectively, these findings indicate that the role of KIT mutations and chromosomal rearrangements in the pathogenesis of GIST/GIPACTs are more complex than previously recognized.
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PMID:The complexity of KIT gene mutations and chromosome rearrangements and their clinical correlation in gastrointestinal stromal (pacemaker cell) tumors. 1216 99

Sixteen gastrointestinal stromal tumors (GISTs) were studied by immunohistochemical analysis and an ultrastructural procedure. The tumor locations were as follows: esophagus (2), stomach (7), small intestine (3), and large intestine (4). Four of the lesions were classified as malignant, 2 as borderline, and 10 as benign. On the basis of the immunohistochemical analysis, the tumors were classified as follows: 1 as myogenic type, 2 as Schwann cell type, 8 as Cajal cell type (including 2 gastrointestinal autonomic nerve tumors, GANTs), and 5 as mixed-cell type. In each subtype the phenotype was compared to the ultrastructural findings. Myogenic and Schwann cell type revealed ultrastructurally smooth muscle differentiation and schwannian tumor. All 8 tumors of the Cajal cell type revealed interdigitating cytoplasmic processes with occasional clusters of filopodia. Two tumors were subdivided as GANT. Five tumors of mixed-cell type were composed of a mixture of cells with variable myogenic features or variable neural differentiation. We confirmed in this study that immunohistochemical analysis reflected electron microscopic findings.
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PMID:Electron microscopic and immunohistochemical studies of gastrointestinal stromal tumors. 1181 Apr 48


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