Wednesday, September 19, 2012

Fibrin-associated Large B-cell Lymphoma: Part of the Spectrum of Cardiac Lymphomas.

Fibrin-associated Large B-cell Lymphoma: Part of the Spectrum of Cardiac Lymphomas.

Oct 2012


*Department of Clinical Pathology, Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH †Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.


Cardiac lymphomas are rare, and the spectrum of pathologic features is not well defined. We encountered an unusual case of cardiac lymphoma residing within a presumed thrombus. To place such cases in context, we reviewed all cardiac lymphomas presenting to a large US cardiovascular medicine referral center during a 30-year period. A total of 14 cardiac lymphomas were identified, and these included 6 primary cardiac lymphomas (PCLs) and 8 lymphomas secondarily involving cardiac structures. Upon review, 3 of the PCLs were confirmed to be diffuse large B-cell lymphoma, not otherwise specified, involving the myocardium. The other 3 cases of PCL lacked myocardial invasion and showed lymphoma cells embedded in fibrin thrombus. Acute inflammation was not evident. These lymphomas presented in immunocompetent male individuals and involved either a prolapsed myxomatous mitral valve, a pseudomyxoma from the left atrium, or a thrombus arising in a synthetic aortic root graft. All 3 consisted of large atypical lymphocytes expressing a nongerminal center B-cellimmunophenotype. Two cases were positive for Epstein-Barr virus (latency type III), but none demonstrated human herpes virus-8 latent nuclear antigen. No systemic disease was found at presentation or during follow-up. In our experience, fibrin-associated large B-cell lymphoma arising in the heart represents a substantial proportion of PCL. These lymphomas appear to represent an underrecognized variant of diffuse large B-cell lymphoma with favorable outcome. Further study is needed to understand their natural history.

Double-hit Lymphomas Constitute a Highly Aggressive Subgroup in Diffuse Large B-cell Lymphomas in the Era of Rituximab.

Double-hit Lymphomas Constitute a Highly Aggressive Subgroup in Diffuse Large B-cell Lymphomas in the Era of Rituximab.

Sept 2012


1Division of Hematology and Oncology, Department of Medicine, Kyoto Prefectural University of Medicine, Kyoto.



The incorporation of rituximab in immunochemotherapy has improved treatment outcomes for diffuse large B-cell lymphoma, but the prognosis for some diffuse large B-cell lymphomas remains dismal. Identification of adverse prognostic subgroups is essential for the choice of appropriate therapeutic strategy.


We retrospectively investigated the impact of so-called 'double-hit' cytogenetic abnormalities, i.e. cytogenetic abnormalities involving c-MYC co-existing with other poor prognostic cytogenetic abnormalities involving BCL2, BCL6 or BACH2, on treatment outcomes for 93 consecutive diffuse large B-cell lymphoma patients.


According to the revised international prognostic index, no patients were cytogenetically diagnosed with double-hit lymphomas in the 'very good' risk group or in the 'good' risk group, while 5 of 33 patients had double-hit lymphomas in the 'poor' risk group. All the double-hit lymphoma patients possessed both nodal and extranodal involvement. The overall complete response rate was 89.3%, overall survival 87.1% and progression-free survival 75.8% over 2 years (median observation period: 644 days). The complete response rates were 93.2% for the non-double-hit lymphoma patients and 40.0% for the double-hit lymphoma patients. Significantly longer progression-free survival and overall survival were observed for the 'very good' and the 'good' risk patients than for the 'poor' risk patients. Moreover, the progression-free survival of double-hitlymphoma was significantly shorter than that of the non-double-hit lymphoma 'poor' risk patients (P = 0.016). In addition, the overall survival of the double-hit lymphoma patients also tended to be shorter than that of the non-double-hit lymphoma 'poor' risk group.


The diagnosis of double-hit lymphoma can help discriminate a subgroup of highly aggressive diffuse large B-cell lymphomas and indicate the need for the development of novel therapeutic strategies for double-hit lymphoma.

Epstein Barr virus presence in pediatric diffuse large B-cell lymphoma reveals a particular association and latency patterns. Analysis of viral role in tumor microenvironment.

Epstein Barr virus presence in pediatric diffuse large B-cell lymphoma reveals a particular association and latency patterns. Analysis of viral role in tumor microenvironment.

Sept 2012


Molecular Biology laboratory. Pathology Division. Ricardo Gutiérrez Children's Hospital. Buenos Aires, Argentina.


Non-Hodgkin's lymphoma represents 6-10% of pediatric malignancies, and diffuse large B-cell lymphoma (DLBCL) is one of the 3 major subtypes. The 2008 WHO classification included a new entity, Epstein-Barr virus (EBV)-positive DLBCL of the elderly, affecting patients >50 years. It has been demonstrated that EBV may play a role in tumor microenvironment composition, disturbing anti-tumor immune response and disease progression.

Since most studies were performed in adults, our aim was to assess EBV presence and latency pattern, as well as T-cell microenvironment in a pediatric DLBCL series of Argentina. The study was conducted on formalin-fixed paraffin-embedded biopsies from 25 DLBCL patients. EBERs expression was performed by in situ hybridization, while EBV gene expression was analyzed using real-time PCR. LMP1, LMP2A, CD3, CD4, CD8 and Foxp3 expression were assessed by immunohistochemistry (IHC). Forty percent of cases showed EBV expression, with a significantly higher incidence among patients <10 years (p=0.018), and with immunosuppressed (p=0.023). T-cell subsets were not altered by EBV presence. 

Full EBV latency antigen expression (latency type III) was the most frequently pattern observed, together with BZLF1 lytic gene expression. One patient showed II like pattern (LMP1 without LMP2A expression). Based exclusively on IHC, some patients showed latency II/III (EBERs and LMP1 expression) or I (EBERs only). These findings suggest that EBV association in our series was higher than the previously demonstrated for elderly DLBCL and that EBV latency pattern could be more complex from those previously observed. Therefore, EBV could be an important cofactor in pediatric DLBCL lymphomagenesis.