Prognostic significance of immunophenotypes in adult lymphoblastic lymphomas

Adult lymphoblastic lymphoma (LBL) can be of T-cell or B-cell lineage. However, the clinical significance of immunophenotypes is largely unknown. We conducted a retrospective study to compare T-cell LBL with its B-cell counterpart. Between 1983 and 1995, 50 adult patients were diagnosed as LBL at National Taiwan University Hospital. Twenty-seven patients (T-LBL:20 and B-LBL:7) had adequate clinical information and formed the basis of final analysis. Pertinent characteristics, including sex, age, and lymphoma stages of these two groups of patients were identical. Detailed clinical features were compared. Systemic involvements of lymphoma were similar except that T-cell LBL had significantly more mediastinal involvement (T:B = 70%:14.3%, p = 0.011). CNS involvement was high in both groups (T:B = 50%:28.6%, p = NS). B-cell LBL had a better overall survival than T-cell LBL, although the survival benefit became less significant after 30 months. The median survival of T- and B-cell LBL was 8 and 31 months, respectively. Both groups taken together, patients who had received prophylactic cranial irradiation had a better overall survival (p < 0.01). We suggest that: a) B-cell LBL has a relatively favorable prognosis than T-cell LBL, at least in the initial 2 to 3 years; b) except for mediastinal involvement, the clinical presentation of T- and B-cell LBL appears to be similar; c) treatment policy, such as the need of prophylactic cranial irradiation, of these two groups may also be similar.