The lymphatic system carries a clear fluid called lymph throughout the body via networks of thin tubes. The lymph transports infection-fighting lymphocytes, removes infectious cells, and carries fats from the intestine to the blood. Key organs involved include the bone marrow, lymph nodes, spleen, and thymus. Lymph nodes and the spleen filter the lymph and blood, respectively. Lymphoma is a cancer of the lymphatic system that causes painless bumps in lymph nodes and general symptoms like fevers and weight loss. Treatment depends on the grade of lymphoma and may include waiting, radiation, or chemotherapy. Life expectancy with lymphoma varies significantly depending on the treatment received and response. Lymphatic obstructions can be caused by