Clover J, Oates J, Edwards C
Department of Histopathology, Birmingham Heartlands Hospital, UK.
Histopathology. 1997 Aug;31(2):140-3. doi: 10.1046/j.1365-2559.1997.2150833.x.
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).
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.
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.