Lymphoblastic Lymphoma In Adults

Abstract

Lymphoblastic lymphoma (LBL) accounts for approximately 4% of all adult patients with non-Hodgkin’s lymphoma (NHL). It is recognised as a distinct clinopathological entity in all of the recently described classifications for NHL, including the Revised European-AmeriPcan Lymphoma (REAL) classification. It is a neoplasm of precursor T or B lymphocytes, which is very similar to acute lymphoblastic leukaemia on the basis of morphology and phenotype. The distinction between ALL and LBL is variable between different treatment centres, and usually based on arbitrary clinical grounds, particularly the degree of bone marrow infiltration or leukaemic overspill. Because of its rarity, it has been the subject of relatively few series in the published literature, and several aspects of its management remain unclear. The results of treatment have improved in recent years, particularly with the use of intensive remission induction therapy similar to that used in acute lymphoblastic leukaemia (ALL). With intensive chemoradiotherapy, most recent series have reported remission rates of 60% to 80%, with long term disease free survival reported in 40% to 60% of patients. Therefore, although high remission rates can be achieved with conventional dose combination chemotherapy, the relapse and progression rate is high. The use of dose intensive therapy in first remission, particularly high dose therapy with stem cell transplantation, has been reported in several series, although its role remains unclear. Similarly, the selection of patients who are at high risk of relapse or progression with conventional therapy has not been reported consistently. The optimal management of patients who fail first line therapy also remains a difficult clinical problem.