Luis Riva

ALK-positive diffuse large B-cell lymphoma: report of four cases and review of the literature

BackgroundAnaplastic lymphoma kinase-positive diffuse large B-cell lymphoma (ALK-DLBCL) is a rare lymphoma with several clinicopathological differences from ALK-positive anaplastic large cell lymphoma (ALCL). The latest WHO classification of lymphomas recognizes ALK-DLBCL as a separate entity.MethodsA comprehensive comparison was made between the clinical and pathological features of the 4 cases reported and those found in an extensive literature search using MEDLINE through December 2008.ResultsIn our series, three cases were adults and one was pediatric. Two cases had primary extranodal disease (multifocal bone and right nasal fossa). Stages were I (n = 1), II (n = 1), III (n = 1) and IV (n = 1). Two cases had increased LDH levels and three reported B symptoms. IPI scores were 0 (n = 1), 2 (n = 2) and 3 (n = 1). All cases exhibited plasmablastic morphology. By immunohistochemistry, cases were positive for cytoplasmic ALK, MUM1, CD45, and EMA; they marked negative for CD3, CD30 and CD20. Studies for EBV and HHV-8 were negative. The survival for the patients with stage I, II, III and IV were 13, 62, 72 and 11 months, respectively.ConclusionALK-DLBCL is a distinct variant of DLBCL with plasmacytic differentiation, which is characterized by a bimodal age incidence curve, primarily nodal involvement, plasmablastic morphology, lack of expression of CD20, aggressive behavior and poor response to standard therapies, although some cases can have prolonged survival as the cases reported in this study. ALK-DLBCL does not seem associated to immunosuppression or the presence of EBV or HHV8. Further prospective studies are needed to optimize therapies for this entity.

Epstein-Barr virus as a prognostic factor in de novo nodal diffuse large B-cell lymphoma.

Although the International Prognostic Index (IPI) score is a valuable prognostic tool in diffuse large B-cell lymphoma (DLBCL), other risk-stratifying factors may be of value. The aim of this study was to define the prognostic value of EBV expression in de novo nodal DLBCL. Seventy-four cases were selected between January 2002 and December 2007. Clinical data were reviewed and tissue samples were evaluated for expression of CD20, CD10, bcl-6, MUM1, and EBV-encoded RNA (EBER). Of 74 evaluated cases, 53 cases (72%) were of non-germinal center-like subtype and 11 cases (15%) were positive for EBER. In a univariate analysis of the 57 patients who received chemotherapy, factors associated with survival were EBV status, performance status, LDH level, and IPI score. Using a multivariate analysis, a prognostic model was developed using IPI score and EBV status, which showed statistical significance. Our study supports EBV status as a powerful prognostic factor in de novo nodal DLBCL. Prospective studies should be carried to validate this hypothesis.

EBV-positive diffuse large B-cell lymphoma in a human T-lymphotropic virus type 1 carrier

The development of B-cell lymphomas has been seldom described in HTLV-1 carriers. We present the case of an elderly Peruvian HTLV-1 carrier who was diagnosed with EBV-positive diffuse large B-cell lymphoma. Despite an initial good response to therapy, patient died during treatment due to fatal Pneumocystis jirovecci pneumonia. EBV infection is characterized by B-cell lymphotropism and selective immunodeficiency. HTLV-1, on the other hand, induces T-cell dysfunction and B-cell proliferation. Finally, immunosenescence is characterized by T-cell dysregulation, decreased apoptosis and cytokine upregulation. In this elderly patient, the combination of EBV and HTLV-1 coinfection and immunosenescence may have played a role in the development of this aggressive diffuse large B-cell lymphoma. Furthermore, the immunodeficiency caused by the viral infections and chemotherapy may have played a role in developing life-threatening infectious complications.