| 1. |
- Dictor, Michael, et al.
(författare)
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Determination of nonendemic nasopharyngeal carcinoma by in situ hybridization for Epstein-Barr virus EBER1 RNA: sensitivity and specificity in cervical node metastases.
- 1995
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Ingår i: Laryngoscope. - 1531-4995. ; 105:4, s. 407-412
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Tidskriftsartikel (refereegranskat)abstract
- After time-consuming and costly investigations, patients with neck metastases from an occult primary often receive unnecessarily large radiation volumes to treat a possible origin in the nasopharynx. In this study a colorimetric antisense Epstein-Barr early ribonucleoprotein 1 (EBER1) oligonucleotide probe specific for Epstein-Barr virus RNA was hybridized in situ to metastatic tissue obtained from 18 nasopharyngeal, 54 oral and pharyngeal, and 12 occult carcinomas derived from an unselected population. All 16 nonkeratinizing nasopharyngeal carcinomas (NPCs) were positive for EBER1. Both cases of keratinizing NPC and all 54 other metastases were negative. A single positive case of occult carcinoma indicated its origin from NPC. In retrospect, 7 patients with occult carcinoma had received unnecessary treatment with irradiation to the nasopharynx. Nasopharyngeal carcinoma appears to be a less common origin of occult carcinoma than previously considered. In the proper clinicopathologic co
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| 2. |
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| 3. |
- Dictor, Michael, et al.
(författare)
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Sinonasal T-cell lymphoma in the differential diagnosis of lethal midline granuloma using in situ hybridization for Epstein-Barr virus RNA
- 1996
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Ingår i: Modern Pathology. - 1530-0285. ; 9:1, s. 7-14
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Tidskriftsartikel (refereegranskat)abstract
- "Lethal midline granuloma" of the upper airways generally encompasses T-cell lymphoma and Wegener's granulomatosis in Western populations. Treatment and outcome for each is different, but their pathological distinction may not always be possible on routine biopsy specimens. Within a defined population between 1947 and 1994, we found 12 cases of primary sinonasal T-cell lymphoma, all with a CD20-, CD3+ immunophenotype in paraffin sections. We studied the occurrence of the Epstein-Barr virus RNA EBER1 using colorimetric in situ hybridization (ISH) with an oligoprobe. All available biopsy specimens from each patient were hybridized to detect the presence of EBER1 in relation to the phase of lymphoma progression. In addition, ISH was performed on 23 cases of nonspecific rhinitis and 10 cases of Wegener's granulomatosis to determine the specificity of the method in the differential diagnosis of inflammatory/ulcerative lesions. In ten cases of lymphoma, initial biopsy specimens showed the early phase with minimal lymphocytic atypia ("polymorphic reticulosis"). Four of these (including one recurrence) had been missed by experienced pathologists, resulting in a diagnostic delay of 2 to 8 yr. The remaining two cases were in the late phase, i.e., malignant grade atypia was apparent in the initial biopsy specimen, and neither was misdiagnosed as being benign. All hybridizable lymphoma sections, regardless of phase of development, gave a strong ISH signal easily detected at low magnification in 50 to 100% of tumor cells. Scattered positive cells were usually present even in necrotic areas. In contrast, no case of Wegener's granulomatosis or nonspecific rhinitis produced a true hybridization signal. We conclude that a negative EBER1 ISH provides strong evidence against T-cell lymphoma in the differential diagnosis of lethal midline granuloma in our population. Conversely, a strong ISH signal for EBER1 in immunohistochemically determined T-cell infiltrates within sinonasal tissues provides strong support for the presence of lymphoma.
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| 4. |
- Dominguez, Mev, et al.
(författare)
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Functional implications of the p.Cys680Arg mutation in the MLH1 mismatch repair protein.
- 2014
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Ingår i: Molecular Genetics & Genomic Medicine. - : Wiley. - 2324-9269. ; 2:4, s. 352-355
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Tidskriftsartikel (refereegranskat)abstract
- In clinical genetic diagnostics, it is difficult to predict whether genetic mutations that do not greatly alter the primary sequence of the encoded protein causing unknown functional effects on cognate proteins lead to development of disease. Here, we report the clinical identification of c.2038 T>C missense mutation in exon 18 of the human MLH1 gene and biochemically characterization of the p.Cys680Arg mutant MLH1 protein to implicate it in the pathogenicity of the Lynch syndrome (LS). We show that the mutation is deficient in DNA mismatch repair and, therefore, contributing to LS in the carriers.
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| 5. |
- Dominguez-Valentin, Mev, et al.
(författare)
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Frequent mismatch-repair defects link prostate cancer to Lynch syndrome
- 2016
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Ingår i: BMC Urology. - : Springer Science and Business Media LLC. - 1471-2490. ; 16:1, s. 15-15
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A possible role for prostate cancer in Lynch syndrome has been debated based on observations of mismatch-repair defective tumors and reports of an increased risk of prostate cancer in mutation carriers. Potential inclusion of prostate cancer in the Lynch syndrome tumor spectrum is relevant for family classification, risk estimates and surveillance recommendations in mutation carriers.METHODS: We used the population-based Danish HNPCC-register to identify all prostate cancers that developed in mutation carriers and in their first-degree relatives from 288 Lynch syndrome families. The tumors were evaluated for clinicopathologic features and mismatch-repair status, and the cumulative risk of prostate cancer was determined.RESULTS: In total, 28 prostate cancers developed in 16 mutation carriers and in 12 first-degree relatives at a median age of 63 years. The majority of the tumors were high-grade tumors with Gleason scores 8-10. Prostate cancer was associated with mutations in MSH2, MLH1 and MSH6 with loss of the respective mismatch repair protein in 69 % of the tumors, though a MSI-high phenotype was restricted to 13 % of the tumors. The cumulative risk of prostate cancer at age 70 was 3.7 % (95 % CI: 2.3-4.9).CONCLUSION: We provide evidence to link prostate cancer to Lynch syndrome through demonstration of MMR defective tumors and an increased risk of the disease, which suggests that prostate cancer should be considered in the diagnostic work-up of Lynch syndrome.
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| 6. |
- Engellau, Jacob, et al.
(författare)
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Tissue microarray technique in soft tissue sarcoma: immunohistochemical Ki-67 expression in malignant fibrous histiocytoma
- 2001
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Ingår i: Applied Immunohistochemistry & Molecular Morphology. - 1533-4058. ; 9:4, s. 358-363
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Tidskriftsartikel (refereegranskat)abstract
- Malignant fibrous histiocytoma (MFH) represents a heterogeneous soft tissue sarcoma entity. The authors compared different methods to determine immunohistochemical staining in whole tissue sections, evaluated the tissue microarray technique, and assessed immunohistochemical heterogeneity using the proliferation marker Ki-67 in 47 histopathologic tumor blocks from 11 MFHs. Whole tissue sections were assessed counting 400 cells along a line and counting all cells in 10 high-power fields (0.16 mm2) with mean Ki-67 expression levels of 13% and 11%, respectively. For the tissue microarray technique, two to three 0.6-mm diameter biopsies were studied from each of the 47 tumor blocks. Good correlation was obtained between whole tissue immunohistochemistry and tissue microarray with the microarray method, giving on average 8.6% greater Ki-67 expression levels than the reference method. Immunohistochemical tumor heterogeneity, evaluated using the high-power field method, showed a median standard deviation of 2.3% within the tumor blocks and 2.5% between the blocks from the same tumor. The authors concluded that the tissue microarray technique yields good quality staining and expression levels for Ki-67 comparable with whole tissue methods in MFH, but because of tumor heterogeneity, several tumor blocks ideally should be studied and, because of loss of material in the microarray process, multiple biopsies should be taken. The feasibility of tissue microarray for immunohistochemical studies of soft tissue sarcomas offers new possibilities to study multiple markers in large tumor materials.
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| 7. |
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| 8. |
- Halvarsson, Britta, et al.
(författare)
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The added value of PMS2 immunostaining in the diagnosis of hereditary nonpolyposis colorectal cancer.
- 2006
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Ingår i: Familial Cancer. - : Springer Science and Business Media LLC. - 1389-9600 .- 1573-7292. ; 5:4, s. 353-358
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Tidskriftsartikel (refereegranskat)abstract
- dentification and characterization of the genetic background in patients with the hereditary nonpolyposis colorectal cancer (HNPCC) syndrome is important since control programmes can in a cost-effective manner prevent cancer development in high-risk individuals. HNPCC is caused by germline mismatch repair (MMR) gene mutations and the genetic analysis of HNPCC therefore includes assessment of microsatellite instability (MSI) and immunohistochemical MMR protein expression in the tumor tissue. MSI is found in >95% of the HNPCC-associated tumors and immunostaining using antibodies against the MMR proteins MLH1, MSH2, and MSH6 has been found to correctly pinpoint the affected gene in about 90% of the cases. The PMS2 antibody was the most recently developed and we have in a clinical material assessed the added value of PMS2 immunostaining in 213 patients with suspected hereditary colorectal cancer. All 119 MSS tumors showed retained expression for all four antibodies and PMS2 did thus not identify any underlying MMR defect in these cases. However, PMS2 immunostaining contributed to the characterization of the MMR defect in a subset of the MSI tumors. Concomitant loss of MLH1 and PMS2, which functionally interact in the MutL alpha complex, was found in 98% of the tumors from patients with germline MLH1 mutations. Among the 12 MSI-high tumors with retained expression of MLH1, MSH2 and MSH6, 8 tumors showed loss of PMS2 staining, and mutations in MLH1 were identified in 2 and mutations in PMS2 in 3 of these individuals. In summary, isolated loss of PMS2 was found in 8% of the MSI-high tumors in our series, including 8/12 previously unexplained MSI-high tumors, in which mutations either in MLH1 or in PMS2 were identified in five cases.
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| 9. |
- Joost, Patrick, et al.
(författare)
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Efficient and reproducible identification of mismatch repair deficient colon cancer : Validation of the MMR index and comparison with other predictive models
- 2013
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Ingår i: BMC Clinical Pathology. - : Springer Science and Business Media LLC. - 1472-6890. ; 13:1, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Background: The identification of mismatch-repair (MMR) defective colon cancer is clinically relevant for diagnostic, prognostic and potentially also for treatment predictive purposes. Preselection of tumors for MMR analysis can be obtained with predictive models, which need to demonstrate ease of application and favorable reproducibility. Methods. We validated the MMR index for the identification of prognostically favorable MMR deficient colon cancers and compared performance to 5 other prediction models. In total, 474 colon cancers diagnosed ≥ age 50 were evaluated with correlation between clinicopathologic variables and immunohistochemical MMR protein expression. Results: Female sex, age ≥60 years, proximal tumor location, expanding growth pattern, lack of dirty necrosis, mucinous differentiation and presence of tumor-infiltrating lymphocytes significantly correlated with MMR deficiency. Presence of at least 4 of the MMR index factors identified MMR deficient tumors with 93% sensitivity and 76% specificity and showed favorable reproducibility with a kappa value of 0.88. The MMR index also performed favorably when compared to 5 other predictive models. Conclusions: The MMR index is easy to apply and efficiently identifies MMR defective colon cancers with high sensitivity and specificity. The model shows stable performance with low inter-observer variability and favorable performance when compared to other MMR predictive models.
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| 10. |
- Joost, Patrick, et al.
(författare)
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Heterogenous mismatch-repair status in colorectal cancer
- 2014
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Ingår i: Diagnostic Pathology. - : Springer Science and Business Media LLC. - 1746-1596. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Immunohistochemical staining for mismatch repair proteins is efficient and widely used to identify mismatch repair defective tumors. The tumors typically show uniform and widespread loss of MMR protein staining. We identified and characterized colorectal cancers with alternative, heterogenous mismatch repair protein staining in order to delineate expression patterns and underlying mechanisms. Methods: Heterogenous staining patterns that affected at least one of the mismatch repair proteins MLH1, PMS2, MSH2 and MSH6 were identified in 14 colorectal cancers. Based on alternative expression patterns macro-dissected and micro-dissected tumor areas were separately analyzed for microsatellite instability and MLH1 promoter methylation. Results: Heterogenous retained/lost mismatch repair protein expression could be classified as intraglandular (within or in-between glandular formations), clonal (in whole glands or groups of glands) and compartmental (in larger tumor areas/compartments or in between different tumor blocks). These patterns coexisted in 9/14 tumors and in the majority of the tumors correlated with differences in microsatellite instability/MLH1 methylation status. Conclusions: Heterogenous mismatch repair status can be demonstrated in colorectal cancer. Though rare, attention to this phenomenon is recommended since it corresponds to differences in mismatch repair status that are relevant for correct classification. Virtual Slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1771940323126788
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