Lymphoblastic lymphoma is a very rare form of non-Hodgkin lymphoma in adults, accounting for less than 3 in 100 cases overall. However, it accounts for more than 1 in 3 of all cases occurring in children and teenagers. It more commonly affects males than females. It may develop from either T- or B-lymphocytes, but in 4 out of 5 cases the T-lymphocytes are affected.
Lymphoblastic lymphoma is very similar to the condition acute lymphoblastic leukaemia (ALL). In ALL, the abnormal lymphocytes are mainly in the blood and bone marrow, whereas in lymphoblastic lymphoma they are generally in the lymph nodes or thymus gland. The two conditions are often treated in very similar ways.