Most chondrosarcomas are composed of hypercellular sheets of chondrocytes which may show a lobular growth pattern (as seen here). Chondrocytes are arranged in clusters and have one or more plump nuclei. Grading of chondrosarcomas is done on the basis of cellularity and the cytologic atypia. Mitotic figures are quite uncommon in chondrosarcomas and are not used in grading. In a 3-tier system, Grade I chondrosarcomas are relatively hypercellular compared to enchondromas and have moderate cytologic atypia.