CK5/6 in effusions: no difference between mesothelioma and pulmonary and nonpulmonary adenocarcinoma.
OBJECTIVE
To test the performance of CK5/6 for the differentiation between mesothelioma, adenocarcinoma and benign mesothelia/proliferations in effusion cytology.


METHODS
CKS/6 immunocytochemistry was applied to ethanol-fixed cytospin preparations from 74 benign and malignant effusions.


RESULTS
Reactivity was seen in 7 of 8 mesotheliomas and in 9 of 11 benign mesothelial proliferations but also in 11 of l7 pulmonary adenocarcinomas and in 12 of 31 adenocarcinomas of nonpulmonary origin. Reactivity was also found in 3 of 5 non-small cell lung carcinomas and 1 of 1 squamous carcinoma.


CONCLUSIONS
CK5/6 reactivity was found in a considerable proportion of metastatic adenocarcinomas of pulmonary and nonpulmonary origin. The high reactivity rate in pulmonary adenocarcinomas disagrees with the results obtained with histologic sections from solid tumor tissue, and CK5/6 seems to be of very limited value as an additional marker in effusion cytology.
Dejmek
Annika
A
Department of Laboratory Medicine, Malmö University Hospital, Lund University, Malmö, Sweden. annika.dejmek@med.lu.se
D000230:Adenocarcinoma / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D053555:Keratin-5 / Q000378:metabolism*; D053553:Keratin-6 / Q000378:metabolism*; D008175:Lung Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D008654:Mesothelioma / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D010996:Pleural Effusion / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D016066:Pleural Effusion, Malignant / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology
D014408:Biomarkers, Tumor; D053555:Keratin-5; D053553:Keratin-6