Chondrosarcoma - clear cell
The patient went on to have a complex resection of L4 vertebral body including left side posterior elements and associated soft tissues, adjacent intervertebral discs, the inferior body of L3 and superior body of L5.
Sections show a clear cell neoplasm arranged as sheets and as lacunae within a cartilaginous matrix. Some woven bone is produced, osteoclasts are present and the lesion is more vascular than a conventional chondrosarcoma. Cells have abundant clear and faintly eosinophilic cytoplasm which is PAS positive in a strong, granular pattern. Nuclei are centrally-located and show low-grade atypia, with occasional mitoses identified. Immunostains demonstrate the lesional cells to be intensely positive for S100, but negative for keratins, EMA, synaptophysin and chromogranin.
Clear cell chondrosarcoma (low-grade, grade 1/3)