CEACAM5 and neoplasm: On the other hand, the biomarkers of chondrosarcoma, such as CEA, EMA, pan-K, and S-100 [26–28], showed a slight positive reaction in the spindle cells of perichondral fibrous tissue (Fig. 4G–J) but an almost negative reaction in the tumor cells of osteochondroma (Fig. 4L–N).