summary Chordomas are malignant tumors of primitive notochordal origin that most commonly occur in the sacrum and coccyx. The tumor typically presents in patients > 50 years of age with insidious low back pain with bowel or bladder dysfunction. Diagnosis is made with biopsy showing foamy, vacuolated, physaliferous cells that are keratin positive on histochemical stains. Treatment is usually wide margin surgical resection with or without radiation. Epidemiology Incidence most common primary malignant spinal tumor in adults Demographics 3:1 male to female ratio usually in patients > 50 years Anatomic location 50% occur in the sacrum and coccyx 35% in spheno-occiptal region 15% in mobile spine Etiology Pathoanatomy forms from malignant transformation in residual notochordal cells resulting in midline location Symptoms Presentation pain insidious onset of pain may be mistaken for low back or hip pain neurologic often complain of bowel or bladder changes sensory deficits rare due to distal nature of tumor gastrointestinal constipation fecal incontinence Physical exam neurologic motor deficits rare because most lesions at S1 or distal bowel and bladder changes are common rectal exam more than 50% of sacral chordomas are palpable on rectal exam Imaging Radiographs often difficult to see lesion due to overlying bowel gas CT will show midline bone destruction and soft tissue mass calcifications often present within the soft tissue lesion MRI bright on T2 useful to evaluate soft tissue extension Histology Biopsy transrectal biopsy is contraindicated Gross lobular and gelatinous Histology findings characterized by foamy, vacuolated, physaliferous cell grows in distinct nodules histochemical staining keratin positive important to distinguish from chondrosarcoma, which is not keratin positive weakly S100 positive Differential Differential of Chordomas Sacral lesions in older patients Keratin stain positive Similar Appearance on Xray Treated with wide-resection alone Chordoma o o o o Chondrosarcoma o o o Metastatic disease o o o Lymphoma o o Multiple Myeloma o MFH o Secondary sarcoma Enchondroma of hand Ollier's Maffucci's Periosteal chondroma Osteochondroma (MHE) Parosteal osteosarcoma o Adamantinoma o o Synovial Sarcoma o Epitheloid sarcoma o Squamous cell o Treatment Nonoperative radiation treatment indications inoperable tumors Operative wide margin surgical resection +/- radiation indications standard of care in most patients technique must be willing to sacrifice sacral nerve roots to obtain adequate surgical margins add radiation if margin not achieved outcomes long-term survival 25-50% en bloc corpectomy has best chance of local control with spinal lesions Complications Local recurrence 50% local recurrence common some newer evidence that radiation with proton-photon beams may be beneficial for recurrence Loss of bowel/bladder function postoperatively to preserve near normal bowel/bladder function preserve bilateral S3 nerve roots preserve unilateral S2, S3, S4 roots when possible Prognosis Metastasis metastatic disease in 30-50% occurs late in the course of the disease so long term follow up required may spread to lung and rarely to bone Survival 60% 5-years survival 25% long term survival local extension may be fatal