disease | Clear Cell Soft Osteosarcoma |
alias | Clear-Cell Chondrosarcoma |
Clear cell osteosarcoma is a rare subtype. It is somewhat similar to chondroblastoma, with a malignancy grade between grade I and II central osteosarcoma.
bubble_chart Pathological Changes
1. Gross examination reveals that the tumor is soft in texture, composed of indistinct cartilaginous material, sometimes with osseous components, and may appear granular. The tumor often presents as red or bloody.
2. Microscopic examination shows that the tumor has a lobular architecture, with centrally located nuclei in clear cells, abundant and clear cytoplasm, strongly positive P.A.S. staining, marked pleomorphism, and rare mitotic figures. At the periphery of the lobules, cells are densely packed, and reactive multinucleated giant cells may be observed. Among these cells, well-differentiated soft osteosarcoma cells, corresponding to grade I–II soft osteosarcoma, can be seen. Occasionally, calcifications (similar to those in chondroblastoma) may be present between cells, and sometimes osteoid-like products (reactive) are visible, which may also be found within the cytoplasm.
bubble_chart Clinical Manifestations
Gender and age are similar to soft osteosarcoma. It is located in the epiphysis or bone protrusions, commonly occurring in the proximal femur, proximal humerus, flat bones, and short bones.
bubble_chart Auxiliary Examination
X-ray findings resemble chondroblastoma occurring in the epiphysis, presenting as a well-defined osteolytic area (at least in the initial stage). However, the lesion may recur after curettage and, if left untreated, can exhibit considerable aggressiveness. Radiopaque calcifications may be observed within the tumor. The tumor grows slowly or very slowly.
bubble_chart Treatment MeasuresExtensive resection is performed with good therapeutic outcomes. Metastasis is rare.