Hodgkin's lymphoma. Coloured X-ray of the spine of a patient with Hodgkin's lymphoma, a malignant (cancerous) growth of white blood cells (lymphocytes). The cancer has spread (metastasised) to one of the vertebrae (orange) making it appear more dense, a condition known as ivory vertebra. Hodgkin's lymphoma is most common in young adults and those over 50. The most common symptom is swollen, non-painful lymph nodes in the upper body. Treatment is with chemotherapy, but once the cancer has spread to the bones the prognosis is poor.