Chordoma, a rare malignant tumor, can develop in the coccyx, or tailbone, and throughout the spine, according to the American Academy of Orthopaedic Surgeons. Chordomas grow slowly, and they can spread to other areas of the body, most often the lungs.
Chrodoma tumors in the coccyx can cause a significant mass, bowl and bladder problems, and numbness in the groin area, states the AAOS. Treatment options include surgery and radiation; traditional chemotherapy is usually not very effective. Chordomas most often develop in people between the ages of 40 and 70 years old, but can sometimes occur in younger patients. Doctors use X-rays, magnetic resonance imaging scans and computed tomography scans to identify chrodomas.