Lymphoma

Any of a variety of cancers that develop in the lymph system, a network of thin vessels and nodes throughout the body which filter the blood and help fight disease and infection. The site of the malignant transformation is usually a lymph node but may be the lymphatic tissue of the marrow, gastrointestinal tract, spleen, skin or other sites. The disease results from the uncontrolled growth and accumulation of malignant lymphocytes. Enlargement of affected lymph nodes is usually the principal manifestation.