Caption

Hodgkin's lymphoma. Coloured composite computed tomography (CT) and positron emission tomography (PET) scan of a patient with growths in her abdomen due to Hodgkin's lymphoma. A radioactive tracer, injected into the patient's bloodstream, has been taken up by the tumours. Hodgkin's lymphoma is a malignant (cancerous) growth of white blood cells (lymphocytes). It is characterised by the presence of Reed- Sternberg cells, a type of lymphocyte. 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 and radiotherapy.