196,134 research outputs found
Cytologic diagnosis of medullary carcinoma of the thyroid gland
No full textThe cytomorphologic features in fine-needle aspiration (FNA) biopsies from 91 histologically verified medullary carcinomas of the thyroid (MCT) were investigated. FNA was able to diagnose neoplasms with indications of surgical removal in 98.9% of cases and moreover, was accurate in specific tumor typing in 89% of cases. The most important cytologic criteria of MCT with FNA are: dispersed cell-pattern of polygonal or triangular cells, azurophilic cytoplasmic granules, and extremely eccentrically placed nuclei with coarse granular chromatin and amyloid. These and other cytologic features of MCT are discussed in detail. Fourteen cases of thyroid tumors originally diagnosed as MCT by cytology are illustrated to discuss the differential diagnosis of MCT and its potential pitfalls. If MCT is cytologically presumed but amyloid and azurophilic cytoplasmic granules are not demonstrated, the use of immunostaining is necessary for a correct tumor typing. The application of immunocytochemistry in MCT is discussed. Diagn. Cytopathol. 2000;22:351-358. (C) 2000 Wiley-Liss, Inc
Analysis of the DNA content in the progression of recurrent and metastatic melanomas
No full textPloidy status and ploidy minted parameters of 18 primary melanomas, 32 recurrences and 18 lymphatic metastases were investigated applying CAS200 image analyzer All the tumours investigated were either suspicious for aneuploidy (Auer III) or clearly aneuploid (Auer IV). Primary melanomas differed from recurrent tumours concerning the percentage of aneuploid cells between 4c and 8c and 5c ER. Comparison of cutaneous tumors with lymphatic metastases showed a significant difference concerning the percentage of aneuploid cells between 2c and 4c. An already high aneuploidy rate in primary rumours suggests that recurrent and metastatic clones of cells are present in early stages and that aneuploidy status in primary melanomas could be regarded as one of the risk factors of recurrences and metastases
Comparison of the DNA content in liver cell adenoma, hepatocellular carcinoma and regenerative nodules
No full textWith regard to neoplasms of hepatocytes, diagnostic pitfalls have been reported for differentiation of live cell adenoma (LCA) from well differentiated hepatocellular carcinoma (HCC). Since cytophotometric analysis of the DNA content with the help of image analysis has proven to be of diagnostic value in various neoplasms, we examined ifs ability to discriminate between LCA and HCC as well as regenerative liver nodules. The material investigated consisted of 54 cases of HCC, 10 benign liver armours and 10 cases suspicious for HCC. All the benign liver tumours demonstrated an euploid histogram. 9 out of 10 borderline tumours were euploid while I out of 10 was suspiciously aneuploid Among HCC, 21 out of 54 were euploid, 18 out of 54 suspiciously and 15 out of 54 clearly aneuploid. 5c exceeding rate differed significantly between benign liver changes and borderline lesions (p=0.0474) as well as between borderline lesions and malignant tumours (p=0.0108). We conclude that the use of image cytometry is helpful as an additional criterion for more diagnostic accuracy in morphologically difficult cases
Comparative study of the expression of DNA mismatch repair genes, the adenomatous polyposis coli gene and growth arrest DNA damage genes in melanoma recurrences and metastases
No full textThe main goal of this study was to examine the expression of DNA mismatch repair genes (MLH1, MSH2, PMS1 and PMS2), the adenomatous polyposis coli (APC) gene and growth arrest DNA damage inducible (GADD) genes (GADD34, GADD45 and GADD153) in the different stages of melanoma recurrences and metastases, and to identify any mutual consistencies in their expression pattern. All the cases of primary melanoma examined showed a reduced expression of DNA repair genes. These results demonstrate that disturbances of DNA repair begin in the early stages of melanoma. No significant differences were found in the expression of these markers between cutaneous melanomas and their recurrences and metastases (P > 0.05). Eighteen significant correlations between markers were found in the primary melanomas, and 10 significant correlations were observed in the first recurrences of melanoma. In contrast, 27 statistically significant relationships were demonstrated in metastatic lymph nodes. The different correlations found in primary and metastatic tumours confirmed the hypothetical difference in marker interaction in the diagnostic groups investigated. Our results suggest that DNA repair genes may play an important role in the recurrence and metastasis of melanomas. (C) 2000 Lippincott Williams & Wilkins
Gene expression analysis of the catalytic subunit of human telomerase (hEST2) in the differential diagnosis of serous effusions
No full textDiagnostic accuracy in effusion cytology based on morphologic examination is not always satisfactory. Therefore, various diagnostic adjuncts such as immunocytochemistry or deoxyribonucleic acid cytometry are employed in this diagnostic field. Recently, demonstration of telomerase activity has been proposed as a possible marker for malignancy. In this study a seminested reverse transcription-polymerase chain reaction (RT-PCR) strategy for expression analysis of the catalytic subunit of human telomerase (hEST2) was used in 58 serous effusions. RT-PCR results correlated with cytologic diagnoses in 14 of 17 malignant effusions. In eight effusions cytologically suspicious for malignancy, PCR results were in accordance with the clinical follow-up. However, hEST2 RT-PCR was also positive in six of 15 cytologically benign effusions that consisted predominantly of inflammatory and mesothelial cells. Using the telomeric repeat amplification protocol, it could be demonstrated that cultured, proliferating benign mesothelial cells may present a weak telomerase activity, as is known in other benign cells including activated lymphocytes. In conclusion, the simple and rapid method of hEST2 RT-PCR serves to support the cytologic diagnosis of malignancy, but false-positive PCR results resulting from activated lymphocytes and proliferating mesothelial cells must be considered
Analysis of the DNA content in the progression of recurrent and metastatic melanomas
No full textPloidy status and ploidy minted parameters of 18 primary melanomas, 32 recurrences and 18 lymphatic metastases were investigated applying CAS200 image analyzer All the tumours investigated were either suspicious for aneuploidy (Auer III) or clearly aneuploid (Auer IV). Primary melanomas differed from recurrent tumours concerning the percentage of aneuploid cells between 4c and 8c and 5c ER. Comparison of cutaneous tumors with lymphatic metastases showed a significant difference concerning the percentage of aneuploid cells between 2c and 4c. An already high aneuploidy rate in primary rumours suggests that recurrent and metastatic clones of cells are present in early stages and that aneuploidy status in primary melanomas could be regarded as one of the risk factors of recurrences and metastases
Comparison of the DNA content in liver cell adenoma, hepatocellular carcinoma and regenerative nodules
No full textWith regard to neoplasms of hepatocytes, diagnostic pitfalls have been reported for differentiation of live cell adenoma (LCA) from well differentiated hepatocellular carcinoma (HCC). Since cytophotometric analysis of the DNA content with the help of image analysis has proven to be of diagnostic value in various neoplasms, we examined ifs ability to discriminate between LCA and HCC as well as regenerative liver nodules. The material investigated consisted of 54 cases of HCC, 10 benign liver armours and 10 cases suspicious for HCC. All the benign liver tumours demonstrated an euploid histogram. 9 out of 10 borderline tumours were euploid while I out of 10 was suspiciously aneuploid Among HCC, 21 out of 54 were euploid, 18 out of 54 suspiciously and 15 out of 54 clearly aneuploid. 5c exceeding rate differed significantly between benign liver changes and borderline lesions (p=0.0474) as well as between borderline lesions and malignant tumours (p=0.0108). We conclude that the use of image cytometry is helpful as an additional criterion for more diagnostic accuracy in morphologically difficult cases
Genetic analysis of the human oncoprotein MDM2 in benign and malignant tumors of the salivary gland
No full textIntroduction: Genetic alterations of oncogene MDM2 promote malignant transformation of several human tumors. In tumors of the salivary gland, however, the genetic status of MDM2 has not been evaluated so far. Methods and Results: Benign and malignant tumors of the salivary gland (6 pleomorphic adenomas, 3 Warthin's tumors, 1 adenocarcinoma, 1 basal cell adenocarcinoma, 1 mucoepidermoid carcinoma, 3 acinic cell carcinomas, 2 adenoid cystic carcinoma, 1 squamous cell carcinoma) were analyzed by fluorescence-based PCR techniques and immunochemistry for MDM2 gene amplification, MDM2 gene expression, MDM2 gene mutation, MDM2 RNA splicing and MDM2 accumulation. Data show that all samples contained nonamplified MDM2 genes with nonmutant zinc finger regions. However, in two benign and two malignant samples, novel MDM2 mRNA splicing variant types 1 and 2 were detected. Furthermore, three malignant tumors revealed significant nuclear MDM2 accumulation. Correlation between levels of MDM2 mRNA and MDM2 protein could not be detected in the specimens. Conclusion: The present study suggests that MDM2 gene mutation and gene amplification do not contribute to MDM2 accumulation detected in malignant tumors of the salivary gland. However, the role of novel MDM2 splicing variants in MDM2 expression and malignant transformation must be elucidated further. Copyright (C) 2001 S. Karger AG, Basel
Relationship between DNA ploidy-related parameters and the deletions in mismatch repair genes MLH1 and MSH2 in lentigo maligna and malignant melanomas
No full textDefects in DNA mismatch repair genes MLH1 and MSH2, first described in hereditary nonpolyposis colon cancer (HNPCC), have been postulated to be responsible for malignant transformation in several tumours. To date there are no data on cutaneous tumours, Using a PCR assay it was possible to identify deletions in MSH2 (exonic regions 12 and 13) in 16 of 47 lentigos maligna and in 10 of 36 malignant melanomas, Deletions in MLH1 (exonic regions 15 and 16) were found in 11 of 47 lentigos and in 15 of 36 melanomas. Comparison of DNA ploidy-related parameters between Lentigos with and without exonic deletions in MSH2 and MLH1 did not show any significant differences. In contrast, melanomas positive and negative for exons 12 and 13 (MSH2) (26/36 and 10/36, respectively) differed significantly with respect to the percentages of diploid cells (P = 0.0179) and tetraploid cells (P = 0.0042). Comparison of melanomas positive and negative for exons 15 and 16 (MLH1) (21/36 and 15/36, respectively) showed significant differences in the percentage of aneuploid cells between 2c and 4c (P = 0.0141) and tetraploid cells (P = 0.0404), In summary, deletions in DNA mismatch repair proteins MSH2 and MLH1 were present both in lentigo maligna and in melanomas and correlated with DNA ploidy; related parameters in malignant melanomas
Analysis of the DNA mismatch repair proteins expression in malignant melanomas
No full textThe importance of properly functioning DNA mismatch repair has been shown in several tumour types both hereditary and sporadic but not yet in malignant melanomas. The aim of this study was to examine the expression of DNA mismatch repair genes (MLH1, MSH2, PMS1 and PMS2) in primary melanomas and to define their possible prognostic impact in 106 primary melanomas. MLH1 was found in 64 and MSH2 in 61 out of 106 melanomas. PMS1 and PMS2 proteins were present in 69 and 67 tumours, respectively. Loss of the expression of DNA mismatch repair proteins correlated with the increase of Clark levels. Cox regression analysis demonstrated some prognostic significance for PMS1 (forward p = 0.0018 and backward selections p=0.0277), MLH1 (only forward selection p =0.0081) and MSH2 (only backward selection p =0.0115)
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