Cancer of the lymphoid tissues. Lymphomas are often described as being large or small cell types, cleaved or noncleaved, diffuse or nodular. The different types often have different prognoses (i.e., prospect of survival or recovery). Some of these lymphomas are named after the physicians who first described them (e.g.,
Burkitt's lymphoma,
Hodgkin's disease). Lymphomas can also be referred to by the organ where they are active such as
CNS lymphomas, which are in the
central nervous system, and GI lymphomas, which are in the
gastrointestinal tract. The types of lymphomas most commonly associated with HIV
infection are called non-Hodgkin's lymphomas or B cell lymphomas. In these types of cancers, certain cells of the lymphatic system grow abnormally. They divide rapidly, growing into tumors.