Lymphoma is an umbrella term used for over 50 related cancers. There are two general categories of lymphoma: Hodgkin and non-Hodgkin lymphoma (NHL).
The difference between Hodgkin lymphoma and NHL is the presence of Reed-Sternberg cells. A Reed-Sternberg cell is a cell derived from a B-lymphocyte and is only present in Hodgkin lymphoma. If Reed-Sternberg cells are present when the tumour is examined under a microscope, the diagnosis is Hodgkin lymphoma. If there are no Reed-Sternberg cells in a lymphatic tumour, the diagnosis is most likely to be NHL. NHL is more common than Hodgkin lymphoma, outnumbering it by a ratio of over six to one. Of all diagnosed lymphoma cases, 85% of them are NHL. Distinguishing between Hodgkin lymphoma and NHL is important to show different patterns of spread and that they require different treatments.