如果整张涂片观察Calretinin呈局灶阳性，Ber-EP4强阳性，就考虑肺腺癌；如果整张涂片Calretinin为阴性，则考虑乳腺癌. Above is not correct.

Both lung and breast cancers (almost all epithelial tumors) are positive for Ber-EP4 and negative for calretinin. Ber-EP4 and calretinin are only used for distinguish epithelial cells from mesothelial cells. They cannot tell the origins and the nature of the cells (benign or malignant). Of cause generally speaking if you find epithelial cells in 腹水 或pleural fluid are metastatic tumors.

Above are basic stain priniciple in fluid IHC. for your reference