Myeloid sarcoma (MS) is a rare neoplasm whose knowledge is largely based on case reports and/or technically dated contributions. Ninety-two MSs in adulthood with clinical data available were evaluated both morphologically and immunohistochemically. Seventy-four cases were also studied by fluorescent in situ hybridization on tissue sections and/or conventional karyotyping on bone marrow or peripheral blood. Histologically, 50% of the tumors were of the blastic type, 43.5% either monoblastic or myelomonocytic and 6.5% corresponded to different histotypes. CD68/KP1 was the most commonly expressed marker (100%), followed by myeloperoxidase (83.6%), CD117 (80.4%), CD99 (54.3%), CD68/PG-M1 (51%), CD34 (43.4%), terminal-deoxy-nucleotidyl-transferase (31.5%), CD56 (13%), CD61/linker for activation of T cells (2.2%), CD30 (2.2%) and CD4 (1.1%). Foci of plasmacytoid monocyte differentiation were observed in intestinal cases carrying inv16. Chromosomal aberrations were detected in about 54% of cases: monosomy 7(10.8%), trisomy 8(10.4%) and mixed lineage leukemia-splitting (8.5%) were the commonest abnormalities, whereas t(8;21) was rare (2.2%). The behavior was dramatic irrespective of presentation, age, sex, phenotype and cytogenetics. Most if not all, long survivors received bone-marrow transplantation. The present report expands the spectrum of our knowledge showing that MS has frequent monoblastic/myelomonocytic differentiation, displays distinctive phenotypic profile, carries chromosomal aberrations other than t(8;21), and requires supra-maximal therapy.

The inability to undergo apoptosis is a crucial mechanism of multidrug resistance in acute myeloid leukemia (AML), and the analysis of mitochondrial apoptotic proteins may represent a significant prognostic tool to predict outcome. Bcl-2 and Bax oncoproteins were evaluated in 255 de novo AML patients (pts) by flow cytometry using an anti–bcl-2 monoclonal antibody (MoAb) and an anti-bax MoAb. The results were expressed as an index (bax/bcl-2) obtained by dividing bax mean fluorescence intensity (MFI) and bcl-2 MFI. Lower bax/bcl-2 ratio was associated with French-American-British (FAB) M0-M1 classes (P = .000 01) and CD34 more than 20% (P < .000 01). There were striking inverse correlations between CD34 or CD117 MFI and bax/bcl-2 values (r = −.40, P < .000 001 andr = −.29, P = .000 002), confirming that immaturity is consistent with this index. Moreover, lower bax/bcl-2 levels were correlated with poor-risk cytogenetics (P = .0002). A significant higher complete remission (CR) rate was found in pts with higher bax/bcl-2 levels (79% versus 45%; P = .000 01). Also, both a longer overall survival (OS) and disease-free survival (DFS) were observed in pts with higher bax/bcl-2 levels (P = .000 01 and = .019). Noteworthy, bax/bcl-2 levels accurately predicted the clinical response and outcome of pts with normal or unknown cytogenetics. Indeed, within this subset of 147 pts, higher bax/bcl-2 ratio was significantly associated both with a higher CR rate (86% versus 42%;P < .000 01) and a longer OS (P = .0016). The independent prognostic value of bax/bcl-2 ratio was confirmed in multivariate analysis. Therefore, mitochondrial oncoproteins, such as bcl-2 and bax, represent both sensitive indicators of clinical outcome and potential targets of novel proapoptotic molecules in order to circumvent chemoresistance.

Background: Hepatitis C virus (HCV) infection is frequently associated with B-cell non-Hodgkin's lymphomas. We investigated the prevalence of HCV infection in nongastric marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT) in order to define the relationship between the viral infection and the presenting features, treatment, and outcome. Methods: We retrospectively studied 172 patients with a histological diagnosis of marginal zone B-cell lymphoma of MALT, except for stomach, and with available HCV serology, among a series of 208 patients. Results: HCV infection was documented in 60 patients (35%). Most HCV-positive patients (97%) showed a single MALT organ involvement. HCV-positive patients showed a more frequent involvement of skin (35%), salivary glands (25%), and orbit (15%). The majority of stage IV HCV-positive patients (71%) had a single MALT site with bone marrow involvement. The overall response rate was similar in HCV-positive (93%) and HCV-negative patients (87%). Overall survival (OS) and event-free survival (EFS) did not differ according to HCV infection. In multivariate analysis, advanced disease (stage III–IV) was associated with a poorer OS (P = 0.0001), irrespective of HCV serostatus. Conclusions: This study shows that nongastric marginal zone lymphomas are characterized by a high prevalence of HCV infection. Patients with involvement of a single MALT site have the highest prevalence of HCV. HCV-positive nongastric lymphomas of MALT show an indolent course similar to HCV-negative patients and seem an ideal target for exploiting the antilymphoma activity of antiviral treatments.

Tumor-targeting mAb are widely used in the treatment of a variety of solid and hematopoietic tumors and represent the first immunotherapeutic approach successfully arrived to the clinic. Nevertheless, the role of distinct immune mechanisms in contributing to their therapeutic efficacy is not completely understood and may vary depending on tumor- or antigen/antibody-dependent characteristics. Availability of next-generation, engineered, tumor-targeting mAb, optimized in their capability to recruit selected immune effectors, re-enforces the need for a deeper understanding of the mechanisms underlying anti-tumor mAb functionality. NK cells participate with a major role to innate anti-tumor responses, by exerting cytotoxic activity and producing a vast array of cytokines. As the CD16 (low-affinity FcγRIIIA)-activating receptor is expressed on the majority of NK cells, its effector functions can be ideally recruited against therapeutic mAb-opsonized tumor cells. The exact role of NK cells in determining therapeutic efficacy of tumor-targeting mAb is still unclear and much sought after. This knowledge will be instrumental to design innovative combination schemes with newly validated immunomodulatory agents. We will summarize what is known about the role of NK cells in therapeutic anti-tumor mAb therapy, with particular emphasis on RTX chimeric anti-CD20 mAb, the first one used in clinical practice for treating B cell malignancies.

The prognostic value of absolute lymphocytic count (ALC), has been a recent matter of debate in non-Hodgkin-lymphoma (NHL). We assessed prospectively the value of ALC at diagnosis and also after the completion of immuno-chemotherapy in 101 diffuse-large-B-cell-lymphoma (DLBCL). Analysis of prognostic factors with respect to overall survival (OS), event free survival (EFS) and progression free survival (PFS) was done by two-tailed log-rank test. The ALC cut-off value was calculated as <0.84 x 10(9)/L at diagnosis: this was a strong negative prognostic factor for OS (p = 0.0004), EFS (p < 0.00001) and PFS (p < 0.00001) and in multivariate analysis was independent from the revised-international-prognostic-index (R-IPI). ALC after chemo-immunotherapy was not of prognostic value. As R-IPI and ALC < 0.84 x 10(9)/L, were the factors better discriminating poor prognosis, a new trichotomous score (ALC/R-IPI) was built up: (1) low risk: R-IPI = very good or good and ALC < 0.84 x 10(9)/L; (2) intermediate risk: patients with at least one risk factor (R-IPI = poor or ALC < 0.84 x 10(9)/L). (3) high risk: patients with both risk factors. This new prognostic score was highly significant in univariate analysis for OS (p = 0.0002), EFS (p < 0.00001) and PFS (p < 0.00001). In multivariate analysis ALC/R-IPI was the most predictive factor for OS (OR = 2.954; p = 0.002) and EFS (OR = 2.381; p < 0.00001) and the only predictive factor for PFS (OR = 4.018; p < 0.00001). Our data, show that ALC at diagnosis has a strong prognostic relevance and is independent from the R-IPI. The new score including both values proved the most powerful predictor at multivariate analysis.