1/36. Expression of vesicular monoamine transporters in endocrine hyperplasia and endocrine tumors of the oxyntic stomach.BACKGROUND: Gastric enterochromaffin-like (ECL) cells selectively express the vesicular monoamine transporter (VMAT) VMAT2, and enterochromaffin (EC) cells the VMAT1 isoform. Aims: We investigated whether VMAT isoform selection indicates the origin of endocrine hyperplasia and neoplasia from oxyntic ECL or EC cells and may be of prognostic significance in different types of gastric carcinoids. methods: Tissue from patients with chronic atrophic gastritis (CAG), Zollinger-Ellison-syndrome (ZES), gastric carcinoids and neuroendocrine carcinoma (NEC) was investigated by immunohistology and in situ hybridization. RESULTS: endocrine cells forming diffuse, linear, and micronodular hyperplasia in CAG and ZES, as well as oxyntic microcarcinoids expressed both VMAT2 and chromogranin a (CgA) but neither VMAT1 nor serotonin. In five of six sporadic carcinoids VMAT2 and CgA but not VMAT1 were detected. One carcinoid was copositive for VMAT1 and serotonin but negative for VMAT2. Electron microscopy confirmed the VMAT2-positive tumors as ECLoma and the VMAT1-immunoreactive carcinoid as EComa. CONCLUSIONS: VMAT2 and VMAT1 are reliable markers for differentiation of gastric endocrine hyperplasia and neoplasia from ECL and EC cells, respectively. The significance of VMAT2 and VMAT1 as prognostic markers lies in the relatively poor prognosis for EComa compared to ECLoma, characterized by VMAT2 positivity. The absence of both VMAT2 and VMAT1 in NEC may indicate poor prognosis.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/36. Interstitial deletion of 8(q13q22) in diffuse large B-cell gastric lymphoma.An interstitial deletion in the long arm of chromosome 8 as the sole structural anomaly was detected in a primary gastric diffuse large B-cell lymphoma, high-grade mucosa-associated lymphoid tissue (MALT) type, from a 74-year-old man. Low-grade MALT lymphoma was not seen in the sections submitted for examination. Helicobactor pylori organisms were found in a biopsy performed prior to resection of the tumor. The karyotype was described as 45, X,-Y,del(8)(q13q22). No rearrangement between chromosome 8 and others was detected with fluorescence in situ hybridization using a whole chromosome 8 painting probe. fluorescence in situ hybridization with the C-MYC gene showed its normal location at 8q24 on both chromosomes 8 without rearrangement. Amplification of C-MYC was not detected in interphase cells. Deletion of 8q may represent a unique genomic alteration in this particular subtype of primary gastric lymphoma.- - - - - - - - - - ranking = 2keywords = hybridization (Clic here for more details about this article) |
3/36. Mucosa-associated lymphoid tissue-type lymphomas occurring in post-transplantation patients.Post-transplantation lymphoproliferative disorders (PTLDs) are usually Epstein-Barr virus (EBV)-associated B-cell lymphoproliferative disorders that vary in their morphologic spectrum. Extranodal marginal zone lymphomas of the mucosa-associated lymphoid tissue-type (MALT-type) have not been considered to be part of this spectrum. The authors encountered five such cases recently. The clinical, histopathologic, and immunophenotypic features are reported. There were three men and two women with a mean age of 51.2 years (range, 48-63 years). Two patients were cardiac transplant recipients, two patients were liver transplant recipients, and the remaining patient was a renal transplant patient. Sites of lymphoma were the stomach in three patients and the parotid gland in two patients. Mean time to the lymphoma was 84 months after transplantation. All patients had morphologic features of low-grade extranodal marginal zone lymphomas of the MALT-type, and helicobacter pylori was present in all three gastric cases. All patients exhibited the B-cell immunophenotype and were negative for EBV by in situ hybridization. These lymphomas were treated with a variety of modalities, including reduction of immunosuppression, antibiotics, surgical resection, radiation therapy, and chemotherapy. At last follow-up, one patient had developed signet ring adenocarcinoma at 27 months but had no evidence of PTLD, one patient relapsed at 17 months but is alive with stable disease at 24 months, and the remaining patients were alive without disease at 11, 12, and 14 months. Extranodal low-grade MALT-type lymphomas can occur in the post-transplantation setting and generally develop years after transplant. As seen in immunocompetent patients, EBV appears to play no role in the pathogenesis of these lymphomas. These lymphomas appear to have more in common with MALT-type lymphomas in nonimmunocompromised patients than conventional PTLDs, although they occur in "at-risk" patients due to their immunosuppressive therapy. These lymphomas do not appear to be clinically aggressive. Recognition of MALT-type lymphomas in the post-transplantation setting as an indolent disease avoids unnecessary treatment.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/36. Synovial sarcoma of the upper digestive tract: a report of two cases with demonstration of the X;18 translocation by fluorescence in situ hybridization.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.- - - - - - - - - - ranking = 6keywords = hybridization (Clic here for more details about this article) |
5/36. Novel translocation of the BCL10 gene in a case of mucosa associated lymphoid tissue lymphoma.Interest has focused on a recently identified gene, BCL10, thought to play an important role in the genesis of extranodal, marginal zone (MALT) lymphomas. This gene belongs to a family containing caspase recruitment domains (CARD), that are involved in the apoptotic pathway. Translocations of the BCL10 gene to the immunoglobulin heavy chain locus at 14q32 have been described. We report herein a case of MALT lymphoma showing t(1; 2)(p22; p12). The translocation was shown to involve the BCL10 gene and the immunoglobulin kappa light chain locus by fluorescence in situ hybridization.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/36. Intratumor heterogeneity of centromere numerical abnormality in multiple primary gastric cancers: application of fluorescence in situ hybridization with intermittent microwave irradiation on paraffin-embedded tissue.Our recent success in retrieving distinct fluorescence signals in response to centromere specific probing of paraffin-embedded tissues after intermittent microwave (MW) treatment provided the opportunity to analyze chromosome numbers or centromere abnormality in situ in human tumors in various clinicopathological settings. In this study, centromere numerical abnormality (CNA) was investigated by fluorescence in situ hybridization (FISH) in a case of multiple gastric cancer having intratumor histological heterogeneity. The different profiles as determined using a total of 20 specific probes on 4 multifocal lesions in the stomach confirmed the multi-clonality of these tumors. FISH with probes specific for chromosomes 10, 11, 16 and 18 revealed intratumor heterogeneity of the CNA, which corresponded to the histological heterogeneity. Our report clearly demonstrates, for the first time, intratumor heterogeneity of CNA and its association with the histological picture, and substantiates the applicability of the MW-assisted FISH protocol to paraffin-embedded pathological specimens.- - - - - - - - - - ranking = 5keywords = hybridization (Clic here for more details about this article) |
7/36. Epstein-Barr virus-associated gastric cancer in a patient with dermatomyositis.A 59-year-old man was admitted presenting systemic rash and muscle weakness. He was diagnosed to have dermatomyositis and a check was made for internal malignancy. Gastrointestinal endoscopy revealed a Borrmann type II tumor on the middle body of the stomach. biopsy specimens showed a well differentiated adenocarcinoma, and total gastrectomy was performed. The final diagnosis was moderately differentiated adenocarcinoma invading into the proper muscular layer, with metastases to regional lymph nodes. Most of the neoplastic cells were shown to be positive for Epstein-Barr virus by means of EBV-encoded rna in situ hybridization. The symptoms of dermatomyositis disappeared completely after surgery.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
8/36. helicobacter pylori-associated gastric MALT lymphoma in liver transplant recipients.BACKGROUND: Immunosuppressed transplant recipients are at increased risk of developing several forms of malignancy. The aim of this study is to report the clinical presentation, treatment, and outcome of four liver transplant recipients with helicobacter pylori-associated gastric mucosae-associated lymphoid tissue (MALT) lymphoma. methods: The medical records of four liver transplant recipients with gastric MALT lymphoma were reviewed. in situ hybridization for Epstein-Barr-encoded ribonucleic acid was performed on formalin-fixed tissues. RESULTS: All four subjects presented with abdominal symptoms at a mean of 6.1 years posttransplant. Ulcerative lesions biopsied at endoscopy demonstrated early-stage gastric MALT lymphoma with associated helicobacter pylori gastritis. in situ hybridization revealed no evidence of Epstein-Barr virus infection in examined tissues. Antibiotic eradication of helicobacter pylori lead to disease remission in three subjects with a mean follow-up of 21 months, and one subject failed to respond to antibiotics and radiation therapy and died from metastatic gastric adenocarcinoma. CONCLUSIONS: Early-stage, low-grade gastric MALT lymphoma that was associated with helicobacter pylori gastritis responded to antibiotic therapy with a sustained clinical remission in three of four treated subjects. If other studies confirm a higher than expected incidence of gastric MALT lymphoma in immunosuppressed transplant recipients with helicobacter pylori infection, screening and treating helicobacter pylori infection in selected transplant patients may prove beneficial.- - - - - - - - - - ranking = 2keywords = hybridization (Clic here for more details about this article) |
9/36. Chromosomal imbalances in gastric cancer. Correlation with histologic subtypes and tumor progression.dna copy number changes were analyzed by comparative genomic hybridization (CGH) in 38 gastric carcinomas and correlated with tumor histologic type and progression. Gains of copy numbers were observed in all tumors, affecting all chromosomes except chromosome 16. The average number of copy number gains was 7 (range, 1-13), most frequently located on chromosomes 11, 12, 15, 17, and 20 in 45% to 97% of tumors. High-level amplifications were found on chromosomes 12, 15, 17, and 20; the latter was affected most frequently (66%). Loss of dna copy numbers was detected in 14 tumors affecting 7 chromosomes. No statistically significant differences in the frequency and pattern of chromosomal imbalances were observed in tumor histologic type (Lauren classification) and grade of differentiation, as well as the prognostic parameters depth of invasion (pT) and lymph node involvement (pN). Our results indicate that in gastric cancer there is no specific recurrent pattern of dna aberrations to be correlated with tumor histologic type or stage. However, CGH analysis could reveal new, recurrent genetic changes in gastric cancer affecting chromosomes sites that harbor genes known to participate in tumorigenesis and progression of several human malignant neoplasms.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
10/36. Gastric choriocarcinoma shows characteristics of adenocarcinoma and gestational choriocarcinoma: a comparative genomic hybridization and fluorescence in situ hybridization study.The authors report two cases of the rare primary gastric choriocarcinoma. These tumors showed an overwhelming predominance of cytotrophoblast- and syncytiotrophoblast-like tumor cells that were positive for beta-human chorionic gonadotrophin, with small foci of glandular differentiation. Beta-human chorionic gonadotrophin was also detected serologically in one patient. comparative genomic hybridization study was performed on one specimen. Copy number gains of chromosomes 12, 17, 20, 22, and X, together with losses on 18q, were the major findings. Except for the gain of chromosome 12, which is known to be uncommon in primary gastric adenocarcinoma but frequently associated with choriocarcinoma, the remaining genomic imbalances were among the most common comparative genomic hybridization findings reported in primary gastric adenocarcinoma. fluorescence in situ hybridization on paraffin sections of both specimens confirmed the presence of polysomy 17 and trisomy 12. These results suggest that primary gastric choriocarcinoma genetically possesses characteristics of both adenocarcinoma and gestational choriocarcinoma. The authors believe this is the first interphase cytogenetics study on this rare tumor, and that the results support the theory that gastric choriocarcinoma arises from alternate differentiation pathways of adenocarcinoma.- - - - - - - - - - ranking = 11keywords = hybridization (Clic here for more details about this article) |
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