Primary bone marrow lymphoma: an uncommon extranodal presentation of aggressive non-hodgkin lymphomas.

Bone marrow involvement by lymphoma is considered a systemic dissemination of the disease arising elsewhere, although some tumors may arise primarily in the bone marrow microenvironment. Primary bone marrow lymphoma (PBML) is a rare entity whose real boundaries and clinicobiological significance are not well defined. Criteria to diagnose PBML encompass isolated bone marrow infiltration, with no evidence of nodal or extranodal involvement, including the bone, and the exclusion of leukemia/lymphomas that are considered to primarily involve the bone marrow. Twenty-one out of 40 lymphomas retrospectively reviewed by the International Extranodal Lymphoma Study Group from 12 institutions in 7 different countries over a 25-year period fulfilled the inclusion criteria. These cases comprised 4 follicular lymphomas (FLs), 15 diffuse large B-cell lymphomas (DLBCLs), and 2 peripheral T-cell lymphomas, not otherwise specified. The FL cases showed paratrabecular infiltration, BCL2 protein and CD10 expression, and BCL2 gene rearrangement. DLBCL showed nodular infiltration in 6 cases and was diffuse in 9 cases; it also showed positivity for BCL2 protein (9/10) and IRF4 (6/8). Median age was 65 years with male predominance. All but 3 FL patients were symptomatic. Most cases presented with cytopenias and high lactate dehydrogenase. Four patients (3 FL cases and 1 DLBCL case) had leukemic involvement. Most DLBCL patients received CHOP-like or R-CHOP-like regimens. The outcome was unfavorable, with a median overall survival of 1.8 years. In conclusion, PBML is a very uncommon lymphoma with particular clinical features and heterogenous histology. Its recognition is important to establish accurate diagnosis and adequate therapy.

The presence of -308A TNFα is associated with anemia and thrombocytopenia in patients with myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) constitute a heterogeneous group of clonal hematological diseases characterized by refractory cytopenia(s). MDS patients show increased levels of tumor necrosis factor alpha (TNFα) which is a multifunctional proinflammatory cytokine. The aim of this work is to examine the presence of -308A/G TNFα variants and to analyze whether it is associated with clinical parameters in a cohort of 101 Argentinean de novo MDS patients. The A/A+A/G genotype at TNFα -308 was overrepresented 2-fold in our population (p=0.0499, odds ratio-OR: 2.107) and these differences were more evident in RA-FAB subtype (p=0.0424, OR: 2.502). The presence of the high expressing -308A allele was associated with lower hemoglobin level (8.3 vs 9.9g/dL; p=0.0206), reduced platelet counts (89,000 vs 130,000/µL; p=0.0381) and younger age (59 vs 68years; p=0.0122) at diagnosis. Also, these patients showed 3.8-fold higher risk of transfusion requirement (76% vs 46%, p=0.0105) during the follow up. In conclusion, the presence of an inherited -308A TNFα, which increases its transcription level, was associated with the MDS phenotype in our cohort of Argentine MDS patients. Also, an overexpression of TNFα may promote an underlying proinflammatory state that cooperates with intrinsic defects within MDS progenitors to increase the severity of certain phenotypic features of the disease.