Lymphomas form in the glands or nodes of the lymphatic system. The lymphatic system is a network of vessels, nodes, and organs (specifically the spleen, tonsils, and thymus) that purify bodily fluids and produce infection-fighting white blood cells, or lymphocytes. Unlike the leukaemias which are sometimes called “liquid cancers,” lymphomas are “solid cancers.” Lymphomas may also occur in different organs such as the stomach, breast or brain. These lymphomas are called extranodal lymphomas. The Lymphoma is subclassified into two categories: Lymphoma of Hodgkin and Lymphoma of Non-Hodgkin. The presence of Reed-Sternberg cells diagnostically differentiates Hodgkin Lymphoma from Non-Hodgkin Lymphoma.