Lam SW, et al. - Clinicohistopathological peculiarities were characterized, immunohistochemistry was done for H3 histone family member 3B (H3F3B), histone H3 trimethylated on lysine 27 (H3K27me3), and p53, and genetic alterations of IDH1 (encoding isocitrate dehydrogenase 1), IDH2 (encoding isocitrate dehydrogenase 2), TP53 and H3F3B were assessed in order to report on clinicopathological and molecular features of clear cell chondrosarcoma, and examine whether these hybrid lesions should be thought to be a collision tumor, conventional chondrosarcoma with clear cell change, or clear cell chondrosarcoma with extensive areas of conventional chondrosarcoma, since this has clinical implications. Based on the clinicopathological characterization and genetic alterations, it is recommended that these lesions should be taken into account to be conventional chondrosarcoma, with clear cell change. Moreover, pathologists should be aware of their existence to circumvent confusion with clear cell chondrosarcoma, dedifferentiated chondrosarcoma, or chondroblastic osteosarcoma.