Lymphoma, myeloma and other blood disorders Blood cancer is a general term used to describe cancers that affect the blood, bone marrow and lymphatic system. There are more than 130 forms of blood cancer as well as other closely related conditions. Here are some of the most common types: Lymphoma Lymphoma is a blood cancer which appears as a solid tumour most commonly in the lymph nodes of the neck, chest, armpit or groin but can be detected elsewhere in the body too. There are two main types of lymphoma, non-Hodgkin lymphoma and Hodgkin lymphoma. Non-Hodgkin lymphoma is the fifth most common cancer in the UK with 13,500 people diagnosed each year. Of those, 60% will be aged over 65. There are many different types of this cancer. Doctors will give NHL a grade, depending on how quickly it is likely to grow. Hodgkin lymphoma is a rarer cancer, with 2,100 people diagnosed each year. There are four types of HL, all containing abnormal cells called Reed-Sternberg cells. These are a type of white blood cell that has become cancerous. Read Yasmin's experience of Hodgkin lymphoma here. Myeloma Myeloma is a kind of plasma cell disorder with a ‘relapsing remitting’ behaviour that requires treatment intermittently. Myeloma, also known as multiple myeloma is a cancer arising from plasma cells, a type of white blood cell which is made in the bone marrow. About 5,500 people are diagnosed with this condition each year. Myeloproliferative neoplasms and Myelodysplastic syndromes Some other conditions are closely related to blood cancers. They are similar because the cells grow in an uncontrolled way. They tend to develop more slowly than blood cancers. There may be too many or too few of certain types of blood cells. The cells may be made too quickly and don’t mature properly or may be damaged. These cells come from myeloid stem cells, which are made in the bone marrow. The main conditions are: Essential thrombocythaemia (ET) Polycythaemia vera (PV) Myelofibrosis (MF ) ET, PV and MF belong to a group of conditions called myeloproliferative neoplasms (MPNs). This is when the bone marrow makes too many of one or more types of blood cell. Myelodysplastic syndrome (MDS) is a blood disorder where some of the blood cells made in the bone marrow are damaged. This means that not enough healthy blood cells make it into the bloodstream. Some people with MPNs and MDS can develop leukaemia.