Chondroblastoma

Chondroblastoma is a benign tumor of cartilaginous derivation seen most often in the 2nd decade of life with a male predominance. The lesion is usually centered on the epiphyseal region at the end of long tubular bones. Proximal humerus, proximal tibia, and distal femur are the most commonly involved locations. Local pain is frequently the presenting symptom. The image shows pink areas of chondroid differentiation on the right and sheets of histiocyte-like tumor cells in the center and to the left.