Anti-cytokeratin 5/6: a positive marker for epithelioid mesothelioma.
OBJECTIVE
Previous studies using frozen material have suggested that cytokeratin 5 is expressed by pleural mesothelioma but not by adenocarcinoma. In the present study, reactions for cytokeratins 5 and 6 were investigated in 33 pleural mesotheliomas and 27 secondary adenocarcinomas of the pleura using formalin-fixed, paraffin-embedded material and a commercially available antibody (anti-cytokeratin 5/6).


RESULTS
All of the adenocarcinomas originated in the peripheral lung. The epithelioid component of the mesotheliomas gave a strongly positive reaction: the reaction in sarcomatoid or desmoplastic areas was absent or weak. Twenty-two of the adenocarcinomas were negative, in four there was a weak, equivocal reaction, and in one there was patchy positivity.


CONCLUSIONS
We conclude that this antibody is potentially a useful positive marker for the identification of the epithelioid variant of mesothelioma in formalin-fixed and paraffin-embedded material.
Clover
J
J
Department of Histopathology, Birmingham Heartlands Hospital, UK.
Oates
J
J
Edwards
C
C
D000912:Antibodies, Neoplasm; D014408:Biomarkers, Tumor; D006801:Humans; D007633:Keratins / Q000032:analysis* / Q000276:immunology; D008654:Mesothelioma / Q000378:metabolism* / Q000473:pathology; D010997:Pleural Neoplasms / Q000378:metabolism* / Q000473:pathology
D000912:Antibodies, Neoplasm; D014408:Biomarkers, Tumor; D007633:Keratins