Lymphoblastic lymphomas

Lymphoblastic lymphomas are an uncommon, but fast-growing (aggressive), type of non-Hodgkin lymphoma (NHL). Lymphoblastic lymphomas are most common in adolescents and younger adults, but they can also develop in older people. Most people are diagnosed under the age of 20 or over the age of 50. Lymphoblastic lymphomas develop most often in young men.

Precursor lymphoblastic lymphomas start when immature lymphocytes (called lymphoblasts) become abnormal during the earliest stages of their development. B cells and T cells are types of lymphocytes.

Precursor B-cell lymphoblastic leukemia/lymphoma (B-LBL) develops from immature B cells. B-LBL sometimes affects organs outside of the lymphatic system (called extralymphatic sites), such as the skin or soft tissues. It usually hasn’t spread to the brain and spinal cord (called the central nervous system, or CNS) when it is first diagnosed. But it often comes back (recurs) in the CNS after treatment.

Precursor T-cell lymphoblastic leukemia/lymphoma (T-LBL) develops from immature T cells. People with T-LBL often have a large collection of abnormal lymphocytes in the chest (called a mediastinal mass). They often have a buildup of fluid in the space between the 2 thin layers of tissue that cover the lungs and line the chest cavity (called pleural effusion) or the sac that surrounds the heart (called pericardial effusion).

B-LBL and T-LBL can be considered either a lymphoma or leukemia, depending on how many areas of bone marrow have lymphoblasts in them. If less than 25% of cells in the bone marrow are lymphoblasts, it is considered a lymphoblastic lymphoma. If more than 25% of cells in the bone marrow are lymphoblasts, it is considered an acute lymphocytic leukemia (ALL).

Chemotherapy is the main treatment for lymphoblastic lymphomas. Some people may also be offered radiation therapy or a stem cell transplant. CNS prophylaxis may be given to prevent lymphoma cells from spreading to the brain and spinal cord.

Lymphoblastic lymphomas are treated with combinations of chemotherapy drugs, including:

• CODOX-M – cyclophosphamide (Cytoxan, Procytox), vincristine (Oncovin), doxorubicin (Adriamycin) and high-dose methotrexate
• CODOX-M/IVAC (Magrath protocol) – CODOX-M plus IVAC, which is ifosfamide (Ifex), etoposide (Vepesid) and cytarabine (Cytosar, Ara-C)
• hyperCVAD – cyclophosphamide, vincristine, doxorubicin, dexamethasone (Decadron, Dexasone), methotrexate and cytarabine
• EPOCH – etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin

External beam radiation therapy is sometimes used to treat a collection of abnormal lymphocytes in the chest.

B-LBL and T-LBL can spread to the CNS. CNS prophylaxis is used to prevent lymphoma cells from entering the brain and spinal cord. Treatments are also given if precursor lymphoblastic lymphoma has spread to the CNS.

CNS prophylaxis or treatment may be given as intrathecal chemotherapy. This means that the chemotherapy drug is injected directly into the cerebrospinal fluid (CSF). The drug used in intrathecal chemotherapy is often methotrexate.

CNS prophylaxis or treatment can also be given with a needle into a vein (intravenously). The drug used for intravenous chemotherapy is high-dose methotrexate.

A stem cell transplant may be an option for some people with precursor lymphoblastic lymphoma who go into remission after chemotherapy. It may also be offered when precursor lymphoblastic lymphoma comes back after treatment (recurs) or when it takes a long time to respond to treatment.