Leucosis is a term that refers to a group of cancers that originate from blood cells. Although this word is commonly used by healthcare professionals, there are a number of synonyms that can be used to describe different types of leucosis. For example, chronic lymphocytic leukemia (CLL) and acute lymphoblastic leukemia (ALL) are both forms of leucosis that affect white blood cells. Non-Hodgkin's lymphoma, lymphocytic lymphoma, and multiple myeloma are also considered forms of leucosis. In addition, some medical professionals use the term lymphoproliferative disorder to describe certain types of leucosis. Regardless of the terminology used, the important thing is to seek proper medical attention if you suspect that you or a loved one may be dealing with a blood cancer.