In contrast to the aforementioned mature hyaline cartilage tumors, this benign lesion consists of round-to-spindled cells resembling immature chondrocytes. The great preponderance involves the epiphyseal region of the distal femur, proximal tibia, and proximal humerus. Both cytology and histology may vary. Most tumor cells will show a sharp cytoplasmic border. The cytoplasm may be lightly eosinophilic to clear, and the round-to-oval nuclei may contain grooves, clefts, or invaginations. Cellular atypia can be identified on occasion. Mitoses are present, and may number as high as 4 per 10 high-power microscopic fields; however, atypical mitoses should be absent. Spindle cells are identified as either separate collections or scattered among the chondroblastic cells. Chondroid matrix may be present and is usually eosinophilic rather than the typical basophilic matrix of hyaline cartilage. Calcifications are either within the matrix or surround individual cells in a "chicken-wire" type configuration (Fig. 11). This is one
of the benign tumors, which can contain multinucleated cells and osteoclast-like giant cells (48). The differential diagnosis would include giant-cell tumor and clear-cell chondrosarcoma. Unlike giant-cell tumor, the background mononuclear cells of chondroblastoma resemble chon-droblasts and not histiocytes. A chondroid matrix is noted and an S-100 immunohistochemical stain will be positive (49). Clear-cell chondrosarcoma typically contains sheets of tumor cells with clear or nearly clear cytoplasm, whereas this is usually a focal occurrence in chondroblastoma.
Was this article helpful?
Deal With Your Pain, Lead A Wonderful Life An Live Like A 'Normal' Person. Before I really start telling you anything about me or finding out anything about you, I want you to know that I sympathize with you. Not only is it one of the most painful experiences to have backpain. Not only is it the number one excuse for employees not coming into work. But perhaps just as significantly, it is something that I suffered from for years.