Lymphoma spreads through tissue, the lymph system and blood. The lymph system distributes lymph throughout the body. When cancerous cells enter the lymph, those cells can travel around the body, taking up residence in places where they can spread the disease to other organs, according to Cleveland Clinic.
Lymphoma involves the growth of malignant cells inside the lymph system. Lymph is a watery, colorless fluid that carries lymphocytes (white blood cells). These cells shield the body from tumor growth and infections; however, once cancer forms in the lymph system, it can spread throughout almost the entire body because lymph tissue is found in many parts of the anatomy. Lymphoma can spread easily to the liver as well as other tissues and organs, notes Cleveland Clinic.
When the doctor performs a diagnosis of lymphoma, he evaluates the degree to which cancer has spread, both inside the lymph system and in the rest of the body, to determine the stage of the cancer. Such tests as chest X-ray, PET scan, CT scan, MRI, gallium scan, lumbar puncture and bone marrow aspiration and biopsy indicate where the cancer has spread throughout the body. Once the doctor knows the stage of the lymphoma, he can determine the best treatment protocol for the patient, as stated by Cleveland Clinic.