Lymphoblasts are early types of white blood cell that the B and T lymphocytes develop from. Lymphoblastic lymphoma is a type of non-Hodgkin's lymphoma that involves the lymphoblasts. It is a high grade lymphoma. There is also a type of leukaemia called Acute Lymphoblastic (or Lymphocytic) Leukaemia (ALL).

Pertaining to a cell of the lymphocytic series; the term implies proliferation. Lymphoblastic is one of the forms of leukemic cancer of the white blood cells characterized by the presence of malignant lymphoblasts or immature lymphocytes.