Adjuvant methods to identify and type tumor cells in serous effusions

BACKGROUND: Malignant mesothelioma (MM) is a rare tumor of the serosal membranes with a poor prognosis. Studies predict an increasing incidence of this tumor in the next decade. An early and precise diagnosis of MMs in effusions is crucial for patient management and may avoid unnecessary invasive procedures. However, this diagnosis represents one of the classic diagnostic challenges of cytopathology in serous effusions. It may be overcome by the application of adjuvant methods. The current study investigated the usefulness of cytology, DNA-image cytometry (DNA-ICM), immunocytochemistry, AgNOR-analysis, and chromosomal fluorescence in situ hybridization (FISH) for the diagnosis of MM and of metastatic carcinoma in serous effusion.MATERIALS AND METHODS: A total of 33 effusions received between March 2005 and May 2007 were cytologically diagnosed as suspicious or positive for MM cells using DNA-ICM, immunocytochemistry and AgNOR-analysis as adjuvant methods. We further investigated the detection of 9p21 deletions by chromosomal FISH. To test the utility of adjuvant methods to identify and type tumor cells in serous effusions, we investigated additionally 31 cases of metastatic carcinomas and 39 of tumor cell-negative effusions containing reactive mesothelial cells only, applying DNA-ICM, immunocytochemistry, AgNOR-analysis and chromosomal FISH. All diagnoses were confirmed by histologic and/or clinical follow up.RESULTS: Using DNA-ICM, aneuploidy was found in 71% of MMs, 100% of metastatic carcinomas and in none of tumor cell-negative effusions. 61.3% of MMs showed their greatest DNA stemline within the range of 1.8c and 2.2c and/or 3.6c and 4.4c, while only 19.4% of metastatic carcinomas showed their greatest stemline in this region. The immunocytochemical marker Calretinin was positive in 100% of MMs, none of metastatic carcinomas and 94.9% of reactive mesothelial cells in tumor cell-negative effusions. BerEP4 showed positivity in 15.6% of MMs, 87.1% of metastatic carcinomas and none of tumor cell-negative effusions. Using AgNOR-analysis, 89.3% of MMs, and 96.7% of metastatic carcinoma showed >= 2.5 AgNOR dots as satellites and >= 4.5 as total AgNOR counts. Only one case of tumor cell-negative effusion revealed an increased number of AgNOR dots. 9p21 homo- and heterozygous deletions were demonstrated in 54.5% and 42.4% of MM cases, respectively. This represents 90.9% of 9p21 deletion, when both criteria are applied. In metastatic carcinomas, the 9p21 homozygous deletion was found in 19.4% and in 32.3% a 9p21 heterozygous deletion. None of the tumor cell-negative effusions demonstrated 9p21 deletions. When cytology alone was used for the diagnosis, 81.8% of MM cases were identified with certainty as tumor cell positive, confirmed by histologic and/or clinical follow-up. The addition of DNA-ICM improved the prevalence of tumor cell detection to 87.9% and the addition of AgNOR-analysis to 97%. The further introduction of FISH as an adjuvant method could improve the prevalence of tumor cell-detection to 100% if 9p21 homo- and heterozygous deletion were used as diagnostic parameters. To differentiate metastatic carcinoma from MM or reactive mesothelial cells, calretinin positivity was found in all cases of MM and in none of metastatic carcinoma; BerEP4 positivity was found in 15.6% of MM, 87.1% of metastatic carcinoma and none of tumor cell- negative effusions. The combination of calretinin positivity and BerEP4 negativity was found in 84.4% of MM cases.CONCLUSION: We have shown that many cases in which cytology on serous effusions is suspicious or doubtful can definitely be solved by one of these adjuvant methods or by their combination and that these may be performed on existing routine cytological smears. The diagnostic methods used in the current study bear individual intrinsic advantages and disadvantages in terms of specificity and sensitivity, laborious effort, and cost effectiveness. Based on our results, we suggest first the parallel application of DNA-ICM, immunocytochemistry, and AgNOR-analysis as adjuvant methods to solve difficult cases of diagnostic cytology in serous effusion. Persistent doubtful diagnoses could be overcome by the application of FISH to analyze the 9p21 deletion. Further studies on larger series of patients are needed to evaluate the validity and efficiency of this approach to improve the diagnostic accuracy of effusion cytology.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2008

Author dc:creator

• Botelho de Miranda Onofre, Fabiana

Contributors dc:contributor

• Wellmann, Axel

• info:eu-repo/classification/ddc/610
• Erguss
• Fluoreszenz-in-situ-Hybridisierung
• Mesotheliom
• Medizin
• effusion
• mesothelioma
• FISH
• DNA-ICM

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

eng

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-112544%22

OAI record oai:identifier

https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A49978