Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Collision tumors of the stomach are uncommon. To the best of our knowledge, this is the first case report of gastric collision tumor composed of gastrointestinal stromal tumor (GIST) intermixed with primary adenocarcinoma in the English literature. The adenocarcinoma was determined to be the primary tumor based on histologic features. The tumor cells of the GIST were diffusely and strongly positive for CD34 and CD117, weakly positive for smooth muscle actin (5% of cells), and negative for desmin, S-100 protein, synaptophysin, and cytokeratin. There was no transition between the different components. We hypothesized that the stomach was influenced by the same unknown carcinogen, resulting in a simultaneous proliferation of different cell lines (epithelial and stromal cell). This case represents an example of two independent tumors in a unique one-on-another pattern, namely growth of adenocarcinoma on GIST.
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PMID:Collision tumor of the stomach: a case report of mixed gastrointestinal stromal tumor and adenocarcinoma. 1235 97

BACKGROUND: HER-2/neu and c-kit (CD117) onco-protein are increasingly being recognized as targets for therapy in solid tumors, but data on their role in malignant melanoma is currently limited. We studied the prevalence of overexpression of HER-2/neu and c-Kit in 202 patients with malignant melanoma to evaluate a possible prognostic value of these molecular targets in malignant melanoma. METHODS: Overexpression of HER-2/neu and c-Kit was evaluated using immunohistochemical assays in 202 archival tissue specimens. RESULTS: Between 1991 and 2001, 202 subjects (109 males; 54% and 93 females; 46%) with malignant melanoma were studied with a mean age of 57 years (age range: 15-101 years). The most common histologic type was amelanotic melanoma (n = 62; 30.7%) followed by superficial spreading melanoma (n = 54; 26.7%). The depth of penetration of melanoma (Breslow thickness, pT Stage) ranged from 0.4 mm (stage pT1) to 8.0 mm (stage pT4A). Mean thickness was 2.6 mm (stage pT3A). The ECOG performance scores ranged from 0 to 3. Only 2 patients (0.9%) revealed HER-2/neu overexpression, whereas 46 (22.8%) revealed c-Kit overexpression. Multivariate analysis performed did not show a significant difference in survival between c-Kit positive and negative groups (p = 0.36). Interestingly, not only was c-Kit more likely to be overexpressed in the superficial spreading type, a preliminary association between the presence or absence of c-Kit overexpression and the existence of another second primary tumor was also observed. CONCLUSIONS: The results of our large study indicate that the HER-2/neu onco-protein neither has a role in melanogenesis nor is a potential target for clinical trials with monoclonal antibody therapy. This indicates there is no role for its testing in patients with malignant melanoma. Although c-Kit, expressed preferentially in the superficial spreading type, may not have prognostic value, it does have significant therapeutic implications as a molecular target warranting further investigation.
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PMID:Immunohistochemical determination of HER-2/neu overexpression in malignant melanoma reveals no prognostic value, while c-Kit (CD117) overexpression exhibits potential therapeutic implications. 1461 73

We report the case of a malignant, primary, hepatic gastrointestinal stromal tumor (GIST) that was resected from the liver of a 79-year-old woman. To our knowledge, this is the first primary, hepatic GIST on record. The tumor expressed CD117 (c-Kit protein) and vimentin and had the ultrastructural features of GISTs. Sixteen months after partial hepatectomy and resection of the tumor, a hilar lymph node metastasis was found. The metastatic tumor had the same morphologic features as the primary tumor, but in addition it contained numerous multinucleated giant cells. This case shows that GIST can occur as a primary liver tumor, and accordingly, we point out that not all hepatic tumors with a GIST phenotype should be automatically considered to be metastases from a primary gastrointestinal site.
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PMID:Primary malignant gastrointestinal stromal tumor of the liver. 1463 69

High-resolution amplicon melting analysis was used to scan for c-kit-activating mutations in exons 9, 11, 13, and 17 in 29 neoplasms diagnosed as gastrointestinal stromal tumors (GISTs). Immunohistochemically, 7 of 29 did not show strong CD 17 positivity and might represent true smooth muscle tumors or c-kit-negative GISTs. No c-kit-activating mutations were detected in the 7 CD117- cases by high-resolution amplicon melting analysis or direct DNA sequencing. Alterations in the remaining 22 CD117+ cases included 13 (59%) in exon 11, 2 (9%) in exon 9, 1 (5%) in exon 13, and none in exon 17. The genetic alterations consisted of point mutations and in-frame insertions, duplications, and deletions. In exon 11, 7 (54%) of 13 alterations have not been described previously. In 2 cases, the identical exon 11 mutation was observed in the primary tumor and a metastatic/recurrent lesion. In all cases, direct DNA sequencing confirmed that polymerase chain reaction products with an abnormal melting curve contained a mutation and products with a normal melting curve, a normal DNA sequence. High-resolution melting analysis can be used to scan DNA for potential c-kit-activating mutations and can aid in the diagnosis of GISTs.
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PMID:Detection of c-kit-activating mutations in gastrointestinal stromal tumors by high-resolution amplicon melting analysis. 1532 37

The purpose of this study was to determine the clinicopathologic features of gastrointestinal stromal tumor (GIST) in southern Taiwan. The pathology files from a medical center in southern Taiwan (1993 to 2003) were searched for primary mesenchymal tumors of the gastrointestinal tract. Hematoxylin/eosin sections and history were reviewed, and immunohistochemistry was performed using anti-CD 117, CD34, smooth muscle actin (SMA), and S-100 protein. Only primary resected GISTs were included in this study. Univariate and multivariate analyses were carried out using the T-test to evaluate the significance of primary tumor size and mitotic activity for the prediction of recurrence and metastasis. A total of 121 surgically resected primary mesenchymal tumors were identified, and 93 of these were GISTs. These 93 patients showed a slight female predominance (male: female = 1:1.2). The clinical presentations were variable and site-dependent. The most common tumor locations were the stomach (57%) and the small intestine (39%). Microscopically, 88 tumors (95%) were composed of spindle cells, the remaining five (5%) consisted of mixed epithelioid and spindle cells. No pure epithelioid type GIST was found. In addition to CD117, 66 cases (71%) were positive for CD34, 23 cases (25%) were positive for SMA, and 19 cases (21%) were positive for S-100. In a mean follow-up time of 27.3 months (median: 26 months), 19 cases (20.6%) were clinically malignant and mainly manifested as liver metastases (seven cases, 37% of malignant GISTs). Univariate analysis revealed that both primary tumor size and mitotic activity were significantly increased in the group affected by recurrence and/or metastasis (p = 0.001 and 0.035, respectively). Compared to GISTs in the western countries, those in southern Taiwan are characterized by a slight female predominance, a relatively higher frequency of small intestinal localization, a higher rate of S-100 protein expression, and a less aggressive behavior. Tumor size and mitotic activity were useful predictors of malignancy.
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PMID:Gastrointestinal stromal tumor (GIST) in southern Taiwan: a clinicopathologic study of 93 resected cases. 1580 5

Five cases of gastrointestinal stromal tumor metastatic to the ovary are reported. The average patient age was 59 years (range, 44-81 years). The primary tumor was in the small bowel or its mesentery (4 cases) or stomach (1 case). The primary and metastatic tumors were discovered synchronously in 3 cases. In the other 2 cases, the ovarian tumors were discovered 18 months before a gastric tumor was identified and 27 years after a small bowel tumor had been resected. The ovarian tumors (three of which were bilateral) were usually solid, tan, and lobulated. Microscopically, three tumors had a pure spindle cell morphology, and two both spindle and epithelioid cell components. The diagnosis in all 5 cases was confirmed with positive c-kit (CD117) and negative desmin immunostaining. Variably positive immunoreactivity for either or both h-caldesmon and smooth muscle actin was seen in all 5 cases, and 3 cases were CD34-positive. Four patients died between 1 and 6.5 years (mean, 2.8 years) from the time of ovarian tumor diagnosis. The main differential diagnostic consideration was leiomyosarcoma; the most important features to help exclude this diagnosis were an absence of tumor in the uterus, low histologic grade, and a desmin-negative, c-kit-positive immunophenotype. Other differential considerations, including endometrial stromal sarcoma and fibrosarcoma, are discussed. Most of the ovarian tumors in this series were initially diagnosed as tumors of other types, a misdiagnosis with significant therapeutic and prognostic implications because of the specific therapy now available for gastrointestinal stromal tumors.
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PMID:Gastrointestinal stromal tumors metastatic to the ovary: a report of five cases. 1595 57

We report on the first case of benign perineurially differentiated peripheral nerve sheath tumor (perineurioma) presenting as a bleeding gastric mass in a 30-year-old, previously healthy woman with no signs or stigmata of von Recklinghausen's disease or other primary tumor at time of presentation. Gastric resection specimen revealed an ulcerated moderately cellular mesenchymal tumor consisting of elongated wavy spindle cells arranged in a fascicular and sheet-like pattern with focal whorling and occasional alternation of dark staining cellular and light staining hypocellular areas. Tumor cells were strongly immunoreactive for epithelial membrane antigen, CD56 (N-CAM), and vimentin, but were negative for S-100-protein and other lineage-specific epithelial, mesenchymal, hematolymphoid, and reticulo-histiocytic markers. CD117 revealed numerous positive staining mast cells, but the lesional cells were not reacting. We presume that the combined histological and immunohistochemical profiles of this unusual gastric neoplasm are consistent with a diagnosis of perineurioma with a probably benign biological behavior. To our knowledge, this is the first report of gastric perineurioma, an extremely rare mesenchymal lesion that should be considered among the differential diagnoses of gastrointestinal stromal tumor, especially the so-called KIT-negative GIST. Gastrointestinal perineuriomas might be under-recognized, as our case was initially diagnosed as a benign GIST.
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PMID:Perineurioma of the stomach. A rare spindle cell neoplasm that should be distinguished from gastrointestinal stromal tumor. 1613 53

Gastrointestinal stroma tumors (GIST), an abdominal stroma entity, are characterized by a gain-in-function mutation in the c-kit proto-oncogen (CD117). Initial treatment should aim at complete removal of the primary tumor (R0 resection), which almost never develops lymphatic metastases. Distant metastatic spread mainly involves the peritoneal cavity and the liver. In patients with metastatic disease, treatment with the tyrosine kinase inhibitor imatinib mesylate is indicated and very effective. Systemic chemotherapy and external beam radiation must be considered ineffective. Patients requiring multivisceral resection for primary tumor removal quickly develop tumor recurrence and could benefit from preoperative treatment with imatinib. To assess the response to treatment, 18F-FDG positron emission tomography or gadolinium-enhanced magnetic resonance imaging have proven helpful, as the conventional criteria of tumor shrinkage according to WHO standards are rarely met. Primary tumors are classified into four risk categories according to size and mitotic activity. The possible advantages of adjuvant treatment are currently under investigation through international randomized trials. Patients who develop extensive remission of metastatic disease should be evaluated individually for resection of the tumor remnants. Even the resection of single progressive lesions (newly developed mutations) should be considered in carefully selected patients if the remaining tumor can be controlled by continued imatinib treatment.
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PMID:[Surgical considerations for gastrointestinal stroma tumor]. 1637 88

Gastrointestinal (GI) stromal tumors (GISTs) are the most common mesenchymal tumors specific to the GI tract, generally defined as KIT (CD117)-positive tumors with a characteristic set of histologic features. These tumors, derived from Cajal cells or their precursors, most commonly occur at the age >50 years in the stomach (60%), jejunum and ileum (30%), duodenum (4-5%), rectum (4%), colon and appendix (1-2%), and esophagus (<1%), and rarely as apparent primary extragastrointestinal tumors in the vicinity of stomach or intestines. Their overall incidence has been estimated as 10 to 20 per million, including incidental minimal tumors. GISTs are rare in children (<1%) and almost exclusively occur in stomach. They are common in patients with neurofibromatosis 1, who have a predisposition to (multiple) small intestinal GISTs. GISTs contain a spectrum from minute indolent tumors to sarcomas at all sites of occurrence. Their gross patterns are diverse, including nodular, cystic, and diverticular tumors. External involvement of pancreas and liver can simulate primary tumor in these organs. In general, gastric tumors have a more favorable prognosis than the intestinal ones with similar parameters. Gastric GISTs < or =10 cm and < or =5 mitoses per 50 HPFs have a low risk for metastasis, whereas those with >5 per 50 HPFs and >5 cm in diameter have a high risk for metastasis. In contrast, all intestinal GISTs >5 cm independent of mitotic rate have at least moderate risk for metastases, and all >5 mitoses per 50 HPFs have a high risk for metastases. Intestinal GISTs < or =5 cm with < or =5 mitoses per 50 HPFs have a low risk for metastases. Gastric GISTs can be divided into histologic subgroups including 4 spindle cell and 4 epithelioid variants. Intestinal GISTs are a histologically more homogeneous group and often contain distinctive extracellular collagen globules, skeinoid fibers. Immunohistochemical demonstration of KIT, CD34, or protein kinase theta positivity helps to properly identify these tumors.
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PMID:Gastrointestinal stromal tumors: pathology and prognosis at different sites. 1719 20

Gastro-intestinal stromal tumors (GIST), an abdominal sarcoma entity are characterized by a gain-of-function mutation in c-kit proto-oncogen (CD117). Initial treatment should aim at complete removal of the primary tumor (R0 resection) which almost never develops lymphatic metastases. Distant metastatic spread involves mainly the peritoneal cavity and the liver. In patients with metastatic disease, treatment with tyrosinkinase inhibitor imatinib mesylate (Glivec) is indicated and very effective. Systemic chemotherapy and external beam radiation must be considered ineffective. Patients requiring multivisceral resection to remove their primary tumor rapidly develop tumor recurrence and could potentially benefit from preoperative treatment with imatinib. Primary tumors are classified into four risk categories according to their size and mitotic activity. Whether there is an advantage of adjuvant treatment is currently under investigation within international randomized trials. Patients who develop an extensive remission of metastatic disease should be evaluated individually for resection of the tumor remnants. Even resection of single progressive lesions (with newly developed mutations) should be considered in carefully selected patients, if the remaining tumor can be controlled by continued imatinib treatment.
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PMID:[Gastrointestinal stromal tumors]. 1725 58


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