A 62-year-old man presents with back pain of several weeks duration. Diagnostic imaging showed the presence of a sacral mass. Surgical biopsy of the mass is performed.
C. – Chordoma
Chordomas are rare tumors, representing less than 5% of all bone tumors. They are more common in men than women and in patients between 50–70 years of age. These tumors are believed to arise from fetal notochordal remnants in the vertebral neuraxis. Chordomas occur along the midline but are more common in the sacrococcygeal region. Histologically, three growth patterns have been described, conventional, chondroid, and dedifferentiated.
Immunohistochemical stains are important in the diagnosis and usually the tumor shows positive staining for cytokeratin, vimentin, and S-100 protein. The tumors may also show positive staining for other epithelial markers including epithelial membrane antigen and carcinoembryonic antigen. The ideal treatment for these tumors appears to be complete surgical resection if possible.