ALBERT

Description: Accelerated phase marks the onset of advanced rapidly progressive chronic myelogenous leukaemia (CML) and generally leads finally to a fatal blast crisis (BC) within 6 months. Gleevec (imatinib mesylate) as a potent tyrosine kinase inhibitor has demonstrated significant activity in chronic phase (CP) of CML. Because of the observed activity and favorable tolerability of Gleevec and because of the limited treatment options available to these patients we have introduced Gleevec in CML patients meeting rigorous criteria for acceleration and blast crisis phase of CML. PATIENTS: MALE - 31 and FEMALE - 20 were eligible for inclusion in this study if they were at least 18 years old and had a diagnosis of Ph+ CML (AP; BC) confirmed by cytology, histology, cytogenetic and molecular analyses. Characteristics CML patients (AP-accelerated phase; BC-blast crisis phase) is showed in table 1. Table 1- Demographics, Disease History and Characteristics of CML Patients. 1 Duration time of CML-yr 3.8 (1–4.5) 3.7 (0.7–5.1) Prior therapy -n(%) 100% 100% combined Chemotherapy 10 (33) 18 (86) BMT 2 (6.6) 0 Sokal’s score 〉0.8 16 (53) 15 (71) PLT (x 109/L) 100.0–300.0 11 (37) 8 (38) 〉300.0 15 (50) 4 (19) Blasts in peripheral blood (%) median 9 34 range 4–20 31–80 Blasts in bone marrow (%) range 10–25 32–78 HGB (g%) median 6.24 6.12 range 5.0–9.4 4.4–10.0 Gleevec dosage AP BC 300mg: n (%) 1 (3.3) 1 (4.8%) 400 mg: n (%) 4 (13.3) 1 (4.8) 600–800 mg: n (%) 25 (83.4) 19 (90.4) Duration of treatment (months) AP BC median 31.64 40.0 range 1–98 0.5–91 Patients received Gleevec 300–800 mg orally daily (table 2). Clinical evaluation of Gleevec therapy was determined by the rate of sustained haematological response (lasting 〉= 4 weeks) The results of Gleevec therapy are showed in table 2. Table 2 - Haematologic Response in Patients with AP & BC Phase after Gleevec Treatment Response AP BC 2 CHR 25 (83.3%) 4 (19.0%) Cytogenetic response Major : 5 (16.7%) 1 (4.8%) CCR 2 (6.7%) 0 PCR 3 (10.0%) 1 (4.8%) Minimal 11 (36.7%) 1.4.8%) No response 9 (30%) 18 (85.6%) BMT performed 5 (16.7%) 2 (9.6%) after Gleevec therapy (months) 6–12 7–13 The most often observed side effects were irst few months ( neutropenia, thrombocytopenia, weakness, bone and muscles pain, headache, nausea, vomiting, diarrhoea, legs’ oedema, deaths (6.3% – 27.3%). Conclusions: Imatinib as a single agent is well tolerated and has substantial activity in the accelerated phase of CML. The overall response rate in these cases was 83%. Imatinib as a single agent is well tolerated and has substantial activity in the accelerated phase of CML. The overall response rate in these cases was 83%. Imatinib as a single agent is well tolerated and has substantial activity in the accelerated phase of CML. The overall response rate in these cases was 83%. 5 pts. out of these 30 patients are still in the chronic phase after 10 to 32 months of follow-up. In 4 ( 19%) out of 21 patients with BC the improvement after Gleevec therapy was short and transient mainly due to advanced stage of disease.

Description: Objectives:Cytogenetics is one of the most important prognostic factors in acute myeloid leukemia (AML). Two major, partially overlapping cytogenetic subsets of AML associated with an adverse prognosis, are AML with complex karyotype (CK) and AML with monosomal karyotype (MK). MK has been shown to constitute a cytogenetic feature that identifies AML patients (pts) with very poor outcomes when treated with currently available therapy. CK-AML pts are very heterogeneous cytogenetically, and treatment outcomes of these subsets are also influenced by TP53 alterations, complexity of the karyotype or presence of residual normal metaphases. However, impact of all these variables on outcome of CK-AML patients was so far analyzed separately. The aim of our study was to assess treatment outcome of CK-AML patients with or without MK regarding some cytogenetic and clinical features. Materials and methods: One hundred twenty five newly diagnosed AML patients with CK treated between January 2007 and January 2013 with PALG protocols (Holowiecki et al., JCO 2012) were included into the study. Cytogenetic analysis was performed on metaphases from bone marrow aspirates taken at diagnosis using standard banding techniques. Karyotypes were reported in accordance with the ISCN 2009. CK was defined as a presence of ≥ 3 unrelated abnormalities. MK was defined by the presence of an autosomal monosomy in conjunction with at least one other autosomal monosomy or structural abnormality in the absence of t(8;21), inv(16), t(15;17) (Breems et al., JCO 2008). FISH method was used to verify MK in all cases with monosomy as well as to assess 17p13 (TP53) deletion. Results:Clinical characteristics. The median age of all pts was 60 years (range 19-85 years). FISH verification proved the MK karyotype (MK+) in 75 out of 125 (60%) pts with CK-AML. Remaining pts had non-monosomal CK (MK-). Sixty six (55%) pts received intensive induction chemotherapy (IC) according to PALG protocols and 59 pts received non-intensive treatment with low-dose cytarabine (LDAC) or best supportive care (BSC). Baseline characteristics were generally balanced between MK+ and MK- groups in terms of age, WBC and PLT counts, hemoglobin level, percentage of bone marrow blasts at diagnosis and presence of residual normal metaphases in the karyotype. Higher proportions of MK+ pts had deletion of 17p13 (TP53) (47,9% vs. 20,4% of MK-; p=0.0017) as well as ≥5 cytogenetic aberrations (93,3% vs. 74%; p=0.004). Furthermore, there were no differences in the proportion of IC, LDAC and BSC strategies between both groups. Treatment Response and Outcome. With the median time of follow-up 7,7 months (mos), median OS in MK- pts was significantly longer compared to MK+ group (4,5 mos vs. 2,0 mos; p=0.0075). 66/125 CK-AML pts received standard IC according to PALG AML protocols (DA-36 pts; DAC-27 pts and DAF-3 pts). Only 7 pts underwent allogeneic stem cell transplantation (allo-SCT). In intensively treated pts the overall CR rate in MK- was about twice as high as in MK+ group (62,1% vs 32,4%; p=0.013). The median OS in MK- pts was longer compared to MK+ group (6,8 mos vs. 2,7 mos; p=0.016). Probability of 1-year OS in MK+ vs. MK- group was 14% vs. 30%. In multivariate analysis we have found that WBC 〉20 G/l, MK and ≥5 chromosomal abnormalities were independent prognostic factors associated with significantly shorter OS (Table 1). In contrast, allo-SCT was associated with survival benefit. Furthermore, we analyzed the impact of purine analogue containing induction regimens on treatment outcome. We found that addition of cladribine to the standard DA regimen improves OS in MK- but not in MK+ group (Figure 1). Conclusions: Monosomal karyotype, high WBC count and high complexity of the karyotype (≥5 aberrations) are associated with more aggressive clinical course and short survival in high-risk CK-AML. Cladribine added to standard DA induction regimen prolongs survival of pts with complex but not monosomal karyotype. *AW and EW equally contributed to the study. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

Description: Key Points This report describes a multidisciplinary study characterizing the largest series of cyclin D1− MCL patients. CCND2 translocations are the most frequent genetic event (55%) in cyclin D1− MCL.

Description: Mantle cell lymphoma (MCL) is characterized by the t(11;14)(q13;q32) translocation resulting in overexpression of cyclin D1. However, a small subset of cyclin D1− MCL has been recognized, and approximately one-half of them harbor CCND2 translocations while the primary event in cyclin D1−/D2− MCL remains elusive. To identify other potential mechanisms driving MCL pathogenesis, we investigated 56 cyclin D1−/SOX11+ MCL by fluorescence in situ hybridization (FISH), whole-genome/exome sequencing, and gene-expression and copy-number arrays. FISH with break-apart probes identified CCND2 rearrangements in 39 cases (70%) but not CCND3 rearrangements. We analyzed 3 of these negative cases by whole-genome/exome sequencing and identified IGK (n = 2) and IGL (n = 1) enhancer hijackings near CCND3 that were associated with cyclin D3 overexpression. By specific FISH probes, including the IGK enhancer region, we detected 10 additional cryptic IGK juxtapositions to CCND3 (6 cases) and CCND2 (4 cases) in MCL that overexpressed, respectively, these cyclins. A minor subset of 4 cyclin D1− MCL cases lacked cyclin D rearrangements and showed upregulation of CCNE1 and CCNE2. These cases had blastoid morphology, high genomic complexity, and CDKN2A and RB1 deletions. Both genomic and gene-expression profiles of cyclin D1− MCL cases were indistinguishable from cyclin D1+ MCL. In conclusion, virtually all cyclin D1− MCLs carry CCND2/CCND3 rearrangements with immunoglobulin genes, including a novel IGK/L enhancer hijacking mechanism. A subset of cyclin D1−/D2−/D3− MCL with aggressive features has cyclin E dysregulation. Specific FISH probes may allow the molecular identification and diagnosis of cyclin D1− MCL.

Description: Abstract 3537 Objectives: Cytogenetics is one of the most important prognostic factors in acute myeloid leukemia (AML). Breems et al., based on banding techniques (BT), have identified a monosomal karyotype (MK) to be associated with particularly poor survival. MK is defined by the presence of an autosomal monosomy in conjunction with at least one other autosomal monosomy or structural abnormality. However, classical BT may be not sufficient to confirm the “real” loss of a particular chromosome, especially in patients with complex karyotype (≥ 3 or ≥ 5 separate abnormalities) where parts of „missing” chromosomes could be involved in structural aberrations such as: additions, derivative chromosomes, rings, marker chromosomes and dicentrics. Molecular cytogenetic techniques, such as FISH, could be useful to verify if observed monosomy was “total” (loss of a complete chromosome) or “partial” (loss of only a part of chromosome including centromere). The aim of our study was to assess if the type of monosomy (total or partial), defined using FISH influences the prognosis of AML patients with MK. Materials and methods: Fifty newly diagnosed AML patients with MK, treated between January 2005 and January 2011 with PALG AML1/2004 and AML2/2004 protocols were included into the study. Cytogenetic analysis was performed on metaphases from bone marrow aspirates taken at diagnosis using standard BT. Karyotypes were centrally reviewed by two independent cytogeneticists and reported in accordance with the ISCN. In 41 cases FISH was performed with painting probes and in justified cases additionally with satellite probes and locus-specific probes to assess the type of monosomy. In 9 patients no confirmation by FISH was needed. Results: In 8/50 (16%) patients FISH verification proved the complex, but not monosomal (total or partial) karyotype. These patients were excluded from further study. The median age of 42 evaluable patients was 58 years (range 20–71 years). There were 26 males and 16 females. Twenty three (55%) patients received intensive induction chemotherapy according to PALG protocols (Holowiecki et al. Leukemia 2004), 8 patients - low dose cytarabine and 11 patients with high frailty index received treatment with hydroxyurea (n=9), and best supportive care (n=2). In 38/42 (90.5%) analyzed cases with MK abnormalities were complex. In all but one ≥5 separate aberrations were present. In 27/42 (64.3%) cases a total monosomy was confirmed by FISH (group A) and in 15/42 (35.7%) cases FISH revealed a monosomy to be the partial one (group B). Both groups A and B were comparable in terms of age, sex, immunophenotype and factors associated with tumor mass (leukemic bone marrow infiltration, WBC and peripheral blood blast count, as well as LDH activity). There was also no difference in the proportion of intensive and non-intensive treatment strategies between both groups. Six (26,1%) of intensively treated patients achieved complete remission (CR). The CR rate in patients with partial monosomy (40%) was higher than in total monosomy group (15,4%), however the difference was not significant (p=0.19; Fisher's exact test). The median overall survival (OS) for all evaluable patients was 66 days (range 1–659 days) and the probability of OS at 1 yr was 14% (95% CI 4–23%). Total monosomy was the only factor associated with decreased probability of OS both in univariate (p=0.036) (Fig. 1) and multivariate (p=0.037) analyses in AML patients with MK. Additionally, in patients with total monosomy the frequency of distinct monosomies was analyzed. The most frequent monosomies were monosomy 7 (n=13; 48%) and monosomy 18 (n=10; 37%). Other total monosomies included: monosomy 17 (n=3; 11%), monosomy 16 (n=2; 7%) and others (n=4). We did not observe any total monosomy 5. Conclusions: Our results indicate for the first time that partial monosomy is associated with significantly better OS than total monosomy in high risk AML with MK and provide further evidence for the heterogeneity of this defined cytogenetic group. These data also clearly demonstrate an important role of FISH method for precise evaluation of complex karyotype, which results in correct classification within MK group, as well as in adequate description of monosomy type. Disclosures: Wierzbowska: Genzyme: Membership on an entity's Board of Directors or advisory committees. Dmoszynska:Roche: Honoraria; Mundipharma:.

Description: Background: The diagnosis of Burkitt lymphoma (BL) is usually based on histopathology (HP), immunohistochemistry (IHC), fluorescence in situ hybridization (FISH) of lymph node or extranodal tissue excisional biopsy and occasionally, on flow cytometry (FCM) of cell suspensions. Accuracy of classical HP/IHC method is highly dependent on the quality sample fixation and takes substantial processing time. In addition, a range of antibodies used in IHC may be insufficient because CD20+/BCL6+/CD10+/BCL2- is not specific for BL. Furthermore, a need for surgery in cases of abdominal presentation may cause delay in initiating curative systemic treatment. Gene expression profiling studies demonstrated that HP/IHC criteria for distinguishing BL from diffuse large B-cell lymphoma (DLBCL) are often inadequate, and 20-30% of BL and DLBCL cases are misdiagnosed and thus inadequately treated. In addition, 5-10% of BL cases have no chromosomal translocation involving the MYC gene (MYC¯) detectable by FISH. We have recently described a BL MYC¯ with recurrent chromosome 11q aberrations. Methods: We evaluated 78 cases of BL, initially diagnosed with HP/IHC, by FCM, classical cytogenetics (CC), and FISH, using cell suspension obtained with fine needle aspiration biopsy (FNAB) of peripheral lymph nodes (n=39), abdominal mass (n=31), cerebrospinal fluid (n=1), pleural effusion (n=4), and bone marrow (n=3). The samples containing at least 70% BL cells were evaluated. 68 cases were MYC+(male/female 52/16, median age/range 34/3-64/, HIV+: 9) and 10 were MYC¯ (male/ female 9/1, median age/range 25/18-62/, all HIV-). Antigen expression on BL cells was compared with normal lymphocytes as well as isotype controls. Antigen expression level was categorized into: [–] - no expression (MFI CD22), majority were CD10/CD43/CD52/CD56/CD79/HLA-DR - positive, and often FMC7 and CD138 positive while they were usually negative for CD5/CD11c/CD23/CD25/CD62L/BCL-2. Expression of CD62L was mostly seen on the small subpopulation of cells. We found a heterogenic type of CD44 and surface light/heavy chains (IgH) of immunoglobulin expression in both types of BL. The moderate intensity expression of clonal sIg and no κ/λ expression was found in 82% and 18% of MYC+, and in 70% and 30% MYC¯ BL cases, respectively.The most frequent pattern of IgH expression was IgM+ (48% and 33,5% in MYC+ and MYC¯, respectively) as well both IgD+/IgM+ (40% and 33,5% in MYC+ and MYC¯, respectively). In addition, proliferative activity measured by CD71 expression was detected in all BL samples on 100% of cells. MYC+ cases demonstrated significantly higher CD38 expression level and absence of CD16&CD56 expression compared to MYC¯ cases. Conclusions: Combined use of FNAB/FCM/CC/FISH is a reliable method for diagnosing BL. BL has a characteristic immunophenotype on FCM examination. MYC+ and MYC¯ cases differ in the level of CD38 and CD16&CD56 expression. CD38 overexpression correlates with MYC rearrangement in MYC+ cases. FCM of a cellular suspension obtained by the FNAB is a safe, relatively non-traumatic, rapid (2 hours), and cost-effective procedure at our institution. Newly diagnosed BL is an oncologic emergency and a quick diagnostic decision is of critical importance in clinical practice. Therefore, we believe that FNAB/FCM/CC/FISH should be the optimal method for diagnosing BL in reference centers. Disclosures No relevant conflicts of interest to declare.

Description: Background: MYC, BCL2 and BCL6 are known to be altered in high grade B-cell lymphoma (HGBL). Double/triple-hit lymphomas (D/THLs) are characterized by chromosomal rearrangementsof MYC, BCL2 and/or BCL6. D/THLs have been included in the updated 2016 WHO classification, as a new category of "High grade B-cell lymphoma with rearrangements" (HGBL-R) or Diffuse Large B-cell lymphoma (DLBCL) entity, depending on morphology/cytogenetic features. BCL2 protein is expressed in a much higher proportion of DLBCL and HGBL, not otherwise specified (HGBL,NOS), and is often associated with a concomitant expression of MYC and BCL6. Most of HGBLs do not carry BCL2/MYC/BCL6 rearrangements and are referred to as "double/triple-expressor lymphomas" (D/TELs). D/THLs patients usually progress rapidly, are resistant to R-CHOP immunochemotherapy, and have very poor prognosis. D/TELs also have a worse outcome than other DLBCL,NOS. BCL2 overexpression is observed in both germinal centre B-cell-like (GCB) and non-GCB HGBL. We have previously described a diagnostic algorithm for subtypes of HGBL based on flow-cytometry immunphenotyping (FCM) with CD38 overexpression, which correlates with MYC rearrangement assessed in fine needle aspiration biopsy (FNAB) samples. Here, we propose that patients with HGBL/DLBCL,NOS, with BCL2 overexpression, especially those with D/THLs and D/TELs, may benefit from DA-EPOCH-R (dose-adjusted cyclophosphamide, doxorubicin, etoposide, vincristine, prednisone with rituximab) treatment. Methods: 30 patients (male/female 18/12, median age/range 51/35-76/) diagnosed with DLBCL,NOS (13 pts), HGBL-R (11 pts), HGBL,NOS (2 pts), primary mediastinal B-cell lymphoma - PMBL (3 pts) and DLBCL,leg type (1 pt), based on 2016 WHO classification, were treated with DA-EPOCH-R as first-line therapybetween January 2015 - July 2016. Clinical stage III or IV and IPI 3 or more were found in 27 pts (90%) and 22 pts (73%), respectively. All cases were evaluated by histopathological/immunohistochemical/flow-cytometry examination (HP/IHC/FCM), with panels of antibodies, including also CD5/CD10/CD20/CD38/BCL2/BCL6/MYC. In most cases, MYC, BCL2, BCL6 and, in case of relapse, also TP53 status was evaluated by karyotyping (CC) and FISH. Results: Considering the cell-of-origin, there were 20 pts with GCB, 3 non-GCB, 4 CD5+ and 3 PMBL. In addition, 15 pts were DEL, 12 - TEL, 3 - one-expressor lymphoma, 8 - D/THL, 12 - one-hit lymphoma and 10 - non-hit lymphoma, mostly with BCL2 overexpression. Karyotype was successfully assessed in 70%, while BCL2 overexpression was found in 83% of HGBL pts. MYC, BCL2, and BCL6 rearrangement was found in 48%, 35% and 21%, respectively. In 50%, 46% and 54% of cases there was an increase in copy number/amplification of MYC, BCL2 and BCL6, respectively. In 15 evaluable pts., overall and complete response was 80% and 53%, respectively. Median follow-up of HGBL pts treated with DA-EPOCH-R was 5 months (range 1-17), and the probability of one year overall survival was 91%, 95% C.I. (80%,100%). Progression free survival at 1 year was 62%, 95C.I. (36%,90%). 3 of 4 patients with progressive disease had TP53 deletion. The main toxicity was pancytopenia with neutropenia grade 3 or more in 24 pts (80%). Treatment-related mortality due to septic shock occurred in 2 patients (7%). Conclusions: DA-EPOCH-R regimen shows a promising activity considering D/THL and D/TEL-associated drug resistance. DA-EPOCH-R regimen seems to overcome drug resistance associated with BCL2/MYC/BCL6 overexpression, but not with TP53 deletion. Combining HP/IHC with FNAB/FCM/CC/FISH is a reliable method for D/THL and D/TEL diagnosis but the most sensitive method for fast MYC/BCL2 rearrangement assessment in DHL is FNAB/FCM CD38 and BCL2 overexpression. Disclosures Rymkiewicz: Takeda: Other: travel, accommodation; Roche: Other: travel, accommodation. Romejko-Jarosinska:Celgene: Other: travel, accommodation; Servier: Other: travel, accommodation; Sanofi- Aventis: Other: travel, accommodation. Paszkiewicz-Kozik:Sandos: Other: fee; Hospira: Other: fee; Sanofi: Other: accommodation; Roche: Other: travel, accommodation. Domanska-Czyz:Roche: Other: travel, accommodation; Amgen: Other: travel, accommodation. Ostrowska:Roche: Other: travel, accommodation; Amgen: Other: travel, accommodation. Dabrowska-Iwanicka:Genzyme: Other: travel, accommodation; Roche: Other: travel, accommodation. Osowiecki:Sandoz: Other: travel, accommodation; Roche: Other: travel, accommodation. Sikorska-Mali:Roche: Other: travel, accommodation. Szymanski:Stada: Other: travel, accommodation. Swierkowska-Czeneszew:Stada: Other: travel, accommodation; Roche: Other: travel, accommodation; Amgen: Other: travel, accommodation. Prochorec-Sobieszek:Roche: Other: travel, accommodation. Walewski:Mundipharma: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Other: travel, accommodation, Research Funding; Takeda: Consultancy, Honoraria, Other: travel, accommodation; Roche: Consultancy, Honoraria, Other: travel, accommodation, Research Funding; Teva: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Other: travel, accommodation; Sanofi: Honoraria, Other: travel, accommodation; Janssen-Cilag: Consultancy; Boehringer Ingelheim: Consultancy; Karyopharm: Consultancy; Ariad: Consultancy; Servier: Consultancy; GSK/Novartis: Research Funding; Genetics: Other: travel, accommodation; Sanofi: Other: travel, accommodation.

Description: Background: Burkitt lymphoma (BL) is characterized by a non-specific morphology and immunophenotype, a high proliferation rate, MYC rearrangements (MYC +), and by a simple karyotype. However, 5% of BL cases have no MYC rearrangements (MYC -) detectable by FISH. It is a matter of debate whether a true MYC (-) BL does exist.The WHO 2008 classification does not clearly define MYC (-) BL cases, and such cases are often misdiagnosed and treated as diffuse large B-cell lymphoma (DLBCL). We have previously described a provisional category of aggressive B-cell lymphoma unclassifiable (BCLU) with recurrent chromosome 11q aberrations, referred to as B-NHL(11q), with clinical, pathomorphological, and gene expression profile features typicalof BL,but MYC (-). B-NHLs(11q) carry proximal gains and telomeric losses of 11q. Karyotyping (CC) and FISH defined the gain region as dup(11)(q23q13) involving CCND1, ATM and KMT2A. As we have recently shown, BL and B-NHL(11q) express different levels of CD38 and CD16&CD56, and both have lower levels of miRNA-155, -21 and -26a than DLBCL. Here we describe a series of BL patients with a set of critical 11q aberrations and propose a diagnostic algorithm for a rapid work-up. Methods: Within a group of 82 BL cases diagnosed and treated with the BL protocol at our institution, we identified 15 cases of B-NHL(11q) with BL features and 11q aberrations: MYC (-) in 11(male/female 10/1, median age [range] 24 [18-62]) and MYC (+) in 4 cases (male/female 3/1, median age [range] 36.5 [20-82]). In MYC (-) pts, the disease was confined to a single site in 82%, was bulky (〉7 cm) in 64% with diameter 〉20 cm in 45% of cases. BL, BCLU and DLBCL diagnosis according to WHO 2008 classification was based on histopathological/immunohistochemical examination (HP/IHC), CC, FISH, and clinical characteristics in all pts. For the final evaluation, the flow cytometry (FCM) immunophenotype, array comparative genomic hybridization (aCGH) data, and miRNA expression was assessed on samples obtained by the fine needle aspiration biopsy (FNAB). In the B-NHL(11q) cases we identified 11q duplication, dup(11q), with an inversion (inv) of the duplicated region and a deletion of its telomeric region, referred to as critical set of 11q aberrations, as opposed to non-critical aberration set that did not involve all three changes. B-NHL(11q) cells were evaluated with the panel of antibodies by IHC (CD20/CD10/BCL6/ BCL2/MUM1/MYC/Ki-67/CD43/CD44), and by FCM with CD (19, 20, 22, 23, 52, 79β, 81, 5, 25, 38, 43, 44, 45, 16&56, 56, 52, 62L, 71, 200), FMC7, HLADR, and BCL2. All B-NHL(11q) cases were evaluated by CC, FISH (MYC, BCL2, BCL6, CCND1, ATM, KMT2A and telomeric 11q) and aCGH. The relative positions of CCND1, ATM, and KMT2A within a duplicated region on the aberrant chromosome 11 were used to identify inversions. Results: A median follow-up of MYC (-) B-NHL(11q) pts treated with the BL regimen was 30 months, and 2-yr OS was 72% (95% CI: 45%, 99%). In 53% of B-NHL(11q) pts tingible body macrophages were less pronounced than in classic BL. All MYC (-) and MYC (+) B-NHLs(11q) cases presented the same phenotype and Ki-67 index of 100% and met the IHC criteria for BL. In MYC (-) and MYC (+) B-NHLs(11q) pts, all with a simple or less simple karyotype, we confirmed a critical or non-critical 11q aberrations in 10 and 5 pts, respectively. In 87% of pts we identified dup(11q), of two types: the larger part between 11q12.1 and 11q24.3 bands, and the smaller part between 11q22.3 and 11q24.1, with an additional multiplication of KMT2A inside the duplication region. In 13% of cases an inv without dup(11q) was detected. We found an inv of dup(11q) region in 73% of all cases, and no inv in dup(11q) in 2 MYC (+) cases only. Bulky tumors of 〉20 cm correlated with increased KMT2A copy number in B-NHLs(11q)cases. Conclusions: B-NHL(11q) cases are clinically homogenous while 11q aberrations are heterogeneous. We believe that BLs MYC (-) do exist. Combination of HP/IHC with FNAB/FCM/CC/FISH is a reliable method for credible diagnosis of BLMYC (-). BLMYC (-) should only be diagnosed in cases where critical 11q aberrations and a simple karyotype are identified. BCLU(11q) or DLBCL(11q) cases should be diagnosed if there are more complex karyotypes accompanied by 11q aberrations of any type. We hypothesize that in BLMYC (-) and other aggressive B-NHL(11q), 11q aberrations may determine clinical and pathomorphological features equivalent to those resulting from MYC rearrangements. Disclosures Walewski: Gilead: Consultancy, Honoraria, Other: travel, accommodation; Seattle: Other: travel, accommodation; GSK/Novartis: Research Funding; Genetics: Other: travel, accommodation; Celgene: Honoraria, Other: travel, accommodation, Research Funding; Teva: Consultancy, Honoraria; Servier: Consultancy; Karyopharm: Consultancy; Boehringer Ingelheim: Consultancy; Ariad: Consultancy; Takeda: Consultancy, Honoraria, Other; Roche: Consultancy, Honoraria, Other: travel, accommodation, Research Funding; Sanofi: Honoraria, Other: travel, accommodation; Mundipharma: Consultancy, Honoraria, Research Funding; Janssen-Cilag: Consultancy.

Description: Mantle cell lymphoma (MCL) is a distinct clinicopathologic entity, characterized by expansion of lymphocytes with co-expression of CD5 and CD20 and frequent t(11;14) translocation. MCL and its morphological variants are frequently confused with other lymphoma subtypes. The aim of this study was to analyze a contribution of histopathology (HP), immunohistochemistry (IHC), flow cytometry (FCM) and cytogenetic analysis with fluorescence in situ hybridization (FISH) to ultimate diagnosis of MCL. We identified 66 pts diagnosed with MCL either by use of HP/IHC or/and FCM. Initial diagnosis was based on HP/IHC only, and was validated in 55 of 66 patients by combined use of HP/IH, FCM, and FISH. We examined paraffin sections IHC panel consisting of antibodies to CD3, CD5, CD20, CD23, CD43, and cyclin D1. FCM analysis was done by 3-colour direct immunofluorescence with extended panel of antibodies to CD5, CD10, CD11c, CD19, CD20, CD22, CD23, CD25, CD38, CD45, HLADR, FMC7, light and heavy chains. We used FISH to detect the t(11;14) in interphase cells of 24 cases of MCL. All 55 cases of MCL were CD20 positive and CD23 negative on IHC, 32 of 51 (63%) and 46 of 52 (88%) cases coexpressed the CD5 and CD43 antigens, respectively. Cyclin-D1 staining revealed nuclear positivity in 38 of 52 (73%) pts. Dual expression of CD5 and cyclin D1 - a finding highly reliable for MCL diagnosis on IHC, was seen in 49% (27/55) of pts. All MCL cases were CD20 (51/51) and CD19 (55/55) positive by FCM with higher intensity of CD20 expression compared to CD19 in 100% (51/51) of cases. CD5 and CD25 were coexpressed in 54 of 55 (98%) and in 43 of 49 (88%) pts respectively. CD22 (45/45) and HLADR (55/55) were positive in all cases. FMC7 and CD38 were found in 22 of 23 (96%) and in 19 of 23 (83%) patients, respectively. CD10, CD11c, CD23 were only seen on a subpopulation of cells with weak intensity in 15%(7/48), 13% (6/45), and 11% (5/46) pts., respectively. MCL cells expressed moderate intensity monoclonal surface light chains in 47 of 52 (90%) pts with L light chain predominance and IgM+/IgD+ in 16 of 17 (94%) pts. False or incomplete initial diagnosis based mainly on lymph node HP/IHC was found in 35 of 66 (53%) cases. False FCM diagnosis of MCL was found in 2 of 66 (3%) cases. Results of FCM and FISH were consistent with the MCL diagnosis in 92% (22/24) of patients, in our hands. Our data indicate that the phenotypic pattern of MCL by FCM is remarkably constant among patients. As MCL represents a frequent diagnostic challenge, a combined use of FCM and FISH may provide an optimum solution.