title: B-lineage lymphoblastic lymphoma is a clinicopathologic entity distinct from other histologically similar aggressive lymphomas with blastic morphology.
abstract: BACKGROUND
  The authors present clinical, histopathologic, and immunophenotypic data regarding B-lineage lymphoblastic lymphoma (B-LBL), a rare entity that has not been extensively studied. To emphasize some of its unique clinical characteristics, the authors compare B-LBL with a group of histologically similar, very aggressive lymphomas, T-lineage lymphoblastic lymphoma (T-LBL) and the blastoid variant of mantle cell lymphoma (BVMCL); all were evaluated concurrently.
  
  
  METHODS
  Clinical data were obtained on 29 patients with very aggressive lymphomas (12 B-LBLs, 10 T-LBLs, and 7 BVMCLs) from whom paraffin-embedded material was available. The diagnoses were confirmed on review of the hematoxylin and eosin-stained slides and the immunophenotype data.
  
  
  RESULTS
  The mean age of patients with B-LBL was 39 years. Patients presented with both lymph node and extranodal disease, although involvement of the mediastinum and bone marrow was infrequent. Four were Stage I, 3 were Stage II, 2 were Stage III, and 3 were Stage IV. B-LBL patients were treated primarily with cyclophosphamide, hydroxydaunomycin, vincristine, and prednisone (CHOP), and one patient underwent allogeneic bone marrow transplantation. The mean follow-up time was 30 months. Seven of 11 had no evidence of disease at 48 months, whereas 4 patients were dead of disease at 5.6 months. The overall median survival was 24 months. The clinical characteristics of B-LBL patients differed significantly from those of T-LBL patients; there was more frequent bone marrow and mediastinal involvement in T-LBL cases (P = 0.03 and 0.04, respectively). T-LBL patients were also less likely to achieve a complete remission than B-LBL patients (P = 0.02). The mean age of BVMCL patients significantly exceeded that of B-LBL patients (P = 0.03).
  
  
  CONCLUSIONS
  The authors believe that the distinction of B-LBL from its histologic mimics, T-LBL and BVMCL, has important clinical implications. Patients with B-LBL present differently from those with the other very aggressive lymphomas studied, and they achieve complete remissions more often than T-LBL patients.
authors.affiliation: Department of Pathology, New York Presbyterian Hospital-Weill Medical School of Cornell University, New York 10021, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Soslow
authors.forename: R N
authors.initials: RN
authors.lastname: Baergen
authors.forename: R A
authors.initials: RA
authors.lastname: Warnke
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016393:Lymphoma, B-Cell / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000473:pathology*; D011379:Prognosis; D016019:Survival Analysis