Histology of grade 1, 2, and 3 chondrosarcoma

While cellularity is low in an atypical cartilaginous tumour/chondrosarcoma grade 1 (ACT/CS1) (A) with chondroid matrix and absent mitoses, in grade 2 chondrosarcoma (B), mitoses are found (inset). In grade 3 chondrosarcoma (C), a high cellularity with muco-myxoid matrix changes is seen with cytonuclear atypia (hematoxylin and eosin staining, approximately 500×).