Anti-cytokeratin 5/6: a positive marker for epithelioid mesothelioma

Histopathology. 1997 Aug;31(2):140-3. doi: 10.1046/j.1365-2559.1997.2150833.x.


Aims: 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).

Methods and 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.

MeSH terms

  • Antibodies, Neoplasm
  • Biomarkers, Tumor*
  • Humans
  • Keratins / analysis*
  • Keratins / immunology
  • Mesothelioma / metabolism*
  • Mesothelioma / pathology
  • Pleural Neoplasms / metabolism*
  • Pleural Neoplasms / pathology


  • Antibodies, Neoplasm
  • Biomarkers, Tumor
  • Keratins