Table 2 Histochemical and immunohistochemical methods used to differentiate mesothelioma from adenocarcinoma
Epithelioid mesotheliomaAdenocarcinoma
    PAS+ (glycogen)+ (small amount of glycogen with mucin)
    plus diastase– (almost always)+
    Alcian blueMay be +
    plus hyaluronidase+Usually still +
    Ber EP4+
    LeuM1 (CD15)+
    Lewisy (BG8)+
    TTF-1+ (lung and thyroid)
  • Note that all may give aberrant or unexpected results occasionally and need to be assessed in combination, and also that adenocarcinomas from non-pulmonary sites may show different expression (for sensitivities and specificities see King et al53 and Ordonez54).