Leukemic Involvement Is a Common Feature in Waldenström Macroglobulinemia at Diagnosis.

Waldenström Macroglobulinemia (WM) is a lymphoplasmacytic lymphoma with bone marrow (BM) involvement and IgM monoclonal gammopathy. To date, no studies have focused specifically on peripheral blood (PB) involvement. In this study, 100 patients diagnosed with WM according to the World Health Organization (WHO) criteria were included based on the demonstration of MYD88mut in BM and the availability of PB multiparametric flow cytometry (MFC) analysis. Leukemic involvement by MFC was detected in 50/100 patients. A low percentage of mature small lymphocytes in PB smears was observed in only 15 cases. MYD88mut by AS-qPCR was detected in PB in 65/100 cases. In cases with leukemic expression by MFC, MYD88mut was detected in all cases, and IGH was rearranged in 44/49 cases. In 21/50 patients without PB involvement by MFC, molecular data were consistent with circulating disease (MYD88mut by AS-qPCR 3/50, IGH rearranged 6/50, both 12/50). Therefore, PB involvement by standard techniques was detected in 71/100 patients. MYD88mut was detected in PB by dPCR in 9/29 triple negative cases. Overall, 80% of the patients presented PB involvement by any technique. Our findings support the role of PB MFC in the evaluation of patients with IgM monoclonal gammopathy and provide reliable information on correlation with molecular features. The development of a feasible MFC assay may stand as an objective tool in the classification of mature B cell neoplasms presenting with IgM monoclonal gammopathy.

Mutational Profile and Pathological Features of a Case of Interleukin-10 and RGS1-Positive Spindle Cell Variant Diffuse Large B-Cell Lymphoma.

Diffuse large B-cell lymphoma with spindle cell morphology is a rare variant. We present the case of a 74-year-old male who initially presented with a right supraclavicular (lymph) node enlargement. Histological analysis showed a proliferation of spindle-shaped cells with narrow cytoplasms. An immunohistochemical panel was used to exclude other tumors, such as melanoma, carcinoma, and sarcoma. The lymphoma was characterized by a cell-of-origin subtype of germinal center B-cell-like (GCB) based on Hans' classifier (CD10-negative, BCL6-positive, and MUM1-negative); EBER negativity, and the absence of BCL2, BCL6, and MYC rearrangements. Mutational profiling using a custom panel of 168 genes associated with aggressive B-cell lymphomas confirmed mutations in ACTB, ARID1B, DUSP2, DTX1, HLA-B, PTEN, and TNFRSF14. Based on the LymphGen 1.0 classification tool, this case had an ST2 subtype prediction. The immune microenvironment was characterized by moderate infiltration of M2-like tumor-associated macrophages (TMAs) with positivity of CD163, CSF1R, CD85A (LILRB3), and PD-L1; moderate PD-1 positive T cells, and low FOXP3 regulatory T lymphocytes (Tregs). Immunohistochemical expression of PTX3 and TNFRSF14 was absent. Interestingly, the lymphoma cells were positive for HLA-DP-DR, IL-10, and RGS1, which are markers associated with poor prognosis in DLBCL. The patient was treated with R-CHOP therapy, and achieved a metabolically complete response.

Epidermotropic B-Cell Lymphoma: A Case of Secondary Cutaneous Splenic Marginal Zone B-Cell Lymphoma With Autoinvolutive and Recurrent Cutaneous Lesions.

ABSTRACT: An 84-year-old woman presented with a 3-month history of a papular rash on the trunk, abdomen, and back. Histopathological examination revealed atypical lymphoid deep and band-like dermal infiltrates with marked epidermotropism. Neoplastic cells expressed B-cell markers (CD20), and clonal immunoglobulin gene rearrangement was observed. A complete peripheral blood study revealed aberrant circulating villous lymphocytes with the expression of B-cell markers (CD20, CD22, and CD79a) and aberrant expression of CD5. A staging workup revealed discrete splenic enlargement and bone marrow and gastrointestinal tract involvement. Skin lesions regressed spontaneously several weeks after diagnosis. Throughout evolution, the patient developed scattered cutaneous nodules and generalized papulo-nodules showing either epidermotropic or nonepidermotropic atypical dermal lymphoid infiltrates. This case illustrates the observation of autoinvolutive and recurrent epidermotropic B-cell atypical cutaneous infiltrates as a characteristic feature of secondary cutaneous involvement in splenic marginal B-cell lymphoma. Previously reported cases of epidermotropic B-cell lymphoma have been reviewed. Concurrent and simultaneous observation of epidermotropic and nonepidermotropic lesions seems to indicate that epidermotropism is an important but nonconstant diagnostic feature of splenic marginal B-cell lymphoma.

Evaluation of 4 prognostic indices in follicular lymphoma treated in first line with immunochemotherapy.

Several clinical risk models have been proposed to predict the outcome of follicular lymphoma (FL). The development of next-generation sequencing technologies has allowed the integration of somatic gene mutations into clinical scores to build genotyped-based risk models, such as the m7-Follicular Lymphoma International Prognostic Index (FLIPI). We explored 4 clinical or clinicogenetic-risk models in patients with symptomatic FL who received frontline immunochemotherapy. Of 191 patients with FL grades 1 to 3a, 109 were successfully genotyped. The treatment consisted of rituximab (R) plus cyclophosphamide, vincristine, and prednisone (R-CVP)/cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) (72.5%) or R-bendamustine (R-B) (27.5%). The proportion of cases classified as high risk for FLIPI, FLIPI-2, PRIMA-prognostic index, or m7-FLIPI were 39.3%, 14%, 30.3%, and 22%, respectively. No case with low-intermediate FLIPI was upgraded in the m7-FLIPI, but 18 of the 42 high-risk patients with FLIPI were downgraded to low-risk m7-FLIPI. The sensitivity and specificity for the prediction of POD24 were highest for FLIPI. The discrimination between progression-free survival (PFS) and overall survival (OS) was the best for FLIPI (c-index: 0.644 and 0.727, respectively). When analyzed only in patients treated with R-B, m7-FLIPI showed a higher discrimination between PFS and OS. Thus, the FLIPI remains the clinical risk score with higher discrimination in patients with advanced FL treated with immunochemotherapy; however, the performance of the m7-FLIPI should be further investigated in patients treated with R-B.

MYC and TP53 Alterations but Not MAPK Pathway Mutations Are Common Oncogenic Mechanisms in Follicular Dendritic Cell Sarcomas.

CONTEXT.­: Despite their stromal origin, follicular dendritic cells (FDCs) share many functions with hematopoietic system cells. FDC neoplasms are currently classified by the World Health Organization along with those of a histiocytic nature. However, the molecular alterations driving oncogenesis in FDC sarcomas (FDCSs) are beginning to be unveiled and do not seem to concur with those described in histiocytic neoplasms, namely MAPK pathway activation. OBJECTIVE.­: To identify molecular alterations driving tumorigenesis in FDCS. DESIGN.­: We investigated the role of MYC and TP53 in FDC-derived tumor oncogenesis and assessed comprehensively the status of the MAPK pathway in 16 FDCSs, 6 inflammatory pseudotumor (IPT)-like FDCSs, and 8 IPTs. RESULTS.­: MYC structural alterations (both amplifications and rearrangements) were identified in 5 of 14 FDCSs (35.7%), all associated with MYC overexpression. TP53 mutations were identified in 4 of 14 FDCSs (28.6%), all of which displayed intense and diffuse p53 expression. None of these alterations were identified in any IPT-like FDCSs or in IPT cases. No MAPK pathway gene alterations were identified in any of the cases studied. CONCLUSIONS.­: The presence of MYC and TP53 alterations and the lack of association with Epstein-Barr virus segregate classical FDCS from IPT-like FDCS, pointing at different oncogenic mechanisms in both entities. Our results suggest a possible oncogenic role of MYC and TP53 alterations in FDCS. The absence of MAPK pathway alterations confirms the lack of a significant role of this pathway in the oncogenesis of FDC-derived neoplasms.

Genetic and phenotypic characterisation of HIV-associated aggressive B-cell non-Hodgkin lymphomas, which do not occur specifically in this population: diagnostic and prognostic implications.

The frequency of aggressive subtypes of B-cell non-Hodgkin lymphoma (B-NHL), such as high-grade B-cell lymphomas (HGBL) with MYC and BCL2 and/or BCL6 rearrangement (HGBL-DH/TH) or Burkitt-like lymphoma (BL) with 11q aberration, is not well known in the HIV setting. We aimed to characterise HIV-associated aggressive B-NHL according to the 2017 WHO criteria, and to identify genotypic and phenotypic features with prognostic impact. Seventy-five HIV-associated aggressive B-NHL were studied by immunohistochemistry (CD10, BCL2, BCL6, MUM1, MYC, and CD30), EBV-encoded RNAs (EBERs), and fluorescence in situ hybridisation (FISH) to evaluate the status of the MYC, BCL2, and BCL6 genes and chromosome 11q. The 2017 WHO classification criteria and the Hans algorithm, for the cell-of-origin classification of diffuse large B-cell lymphomas (DLBCL), were applied. In DLBCL cases, the frequencies of MYC and BCL6 rearrangements (14.9 and 27.7%, respectively) were similar to those described in HIV-negative patients, but BCL2 rearrangements were infrequent (4.3%). MYC expression was identified in 23.4% of DLBCL cases, and coexpression of MYC and BCL2 in 13.0%, which was associated with a worse prognosis. As for BL cases, the expression of MUM1 (30.4%) conferred a worse prognosis. Finally, the prevalence of HGBL-DH/TH and BL-like with 11q aberration are reported in the HIV setting. The phenotypic and genotypic characteristics of HIV-associated aggressive B-NHL are similar to those of the general population, except for the low frequency of BCL2 rearrangements in DLBCL. MYC and BCL2 coexpression in DLBCL, and MUM-1 expression in BL, have a negative prognostic impact on HIV-infected individuals.

High PTX3 expression is associated with a poor prognosis in diffuse large B-cell lymphoma.

Tumor-associated macrophages (TAMs) are associated with a poor prognosis of diffuse large B-cell lymphoma (DLBCL). As macrophages are heterogeneous, the immune polarization and their pathological role warrant further study. We characterized the microenvironment of DLBCL by immunohistochemistry in a training set of 132 cases, which included 10 Epstein-Barr virus-encoded small RNA (EBER)-positive and five high-grade B-cell lymphomas, with gene expression profiling in a representative subset of 37 cases. Diffuse large B-cell lymphoma had a differential infiltration of TAMs. The high infiltration of CD68 (pan-macrophages), CD16 (M1-like), CD163, pentraxin 3 (PTX3), and interleukin (IL)-10-positive macrophages (M2c-like) and low infiltration of FOXP3-positive regulatory T lymphocytes (Tregs) correlated with poor survival. Activated B cell-like DLBCL was associated with high CD16, CD163, PTX3, and IL-10, and EBER-positive DLBCL with high CD163 and PTX3. Programmed cell death-ligand 1 positively correlated with CD16, CD163, IL-10, and RGS1. In a multivariate analysis of overall survival, PTX3 and International Prognostic Index were identified as the most relevant variables. The gene expression analysis showed upregulation of genes involved in innate and adaptive immune responses and macrophage and Toll-like receptor pathways in high PTX3 cases. The prognostic relevance of PTX3 was confirmed in a validation set of 159 cases. Finally, in a series from Europe and North America (GSE10846, R-CHOP-like treatment, n = 233) high gene expression of PTX3 correlated with poor survival, and moderately with CSF1R, CD16, MITF, CD163, MYC, and RGS1. Therefore, the high infiltration of M2c-like immune regulatory macrophages and low infiltration of FOXP3-positive Tregs is associated with a poor prognosis in DLBCL, for which PTX3 is a new prognostic biomarker.

Distinct roles for PARP-1 and PARP-2 in c-Myc-driven B-cell lymphoma in mice.

Dysregulation of the c-Myc oncogene occurs in a wide variety of hematologic malignancies, and its overexpression has been linked with aggressive tumor progression. Here, we show that poly (ADP-ribose) polymerase 1 (PARP-1) and PARP-2 exert opposing influences on progression of c-Myc-driven B-cell lymphoma. PARP-1 and PARP-2 catalyze the synthesis and transfer of ADP-ribose units onto amino acid residues of acceptor proteins in response to DNA strand breaks, playing a central role in the response to DNA damage. Accordingly, PARP inhibitors have emerged as promising new cancer therapeutics. However, the inhibitors currently available for clinical use are not able to discriminate between individual PARP proteins. We found that genetic deletion of PARP-2 prevents c-Myc-driven B-cell lymphoma, whereas PARP-1 deficiency accelerates lymphomagenesis in the Eµ-Myc mouse model of aggressive B-cell lymphoma. Loss of PARP-2 aggravates replication stress in preleukemic Eµ-Myc B cells, resulting in accumulation of DNA damage and concomitant cell death that restricts the c-Myc-driven expansion of B cells, thereby providing protection against B-cell lymphoma. In contrast, PARP-1 deficiency induces a proinflammatory response and an increase in regulatory T cells, likely contributing to immune escape of B-cell lymphoma, resulting in an acceleration of lymphomagenesis. These findings pinpoint specific functions for PARP-1 and PARP-2 in c-Myc-driven lymphomagenesis with antagonistic consequences that may help inform the design of new PARP-centered therapeutic strategies, with selective PARP-2 inhibition potentially representing a new therapeutic approach for the treatment of c-Myc-driven tumors.

High TNFRSF14 and low BTLA are associated with poor prognosis in Follicular Lymphoma and in Diffuse Large B-cell Lymphoma transformation.

The microenvironment influences the behavior of follicular lymphoma (FL) but the specific roles of the immunomodulatory BTLA and TNFRSF14 (HVEM) are unknown. Therefore, we examined their immunohistochemical expression in the intrafollicular, interfollicular and total histological compartments in 106 FL cases (57M/49F; median age 57-years), and in nine relapsed-FL with transformation to DLBCL (tFL). BTLA expression pattern was of follicular T-helper cells (TFH) in the intrafollicular and of T-cells in the interfollicular compartments. The mantle zones were BTLA+ in 35.6% of the cases with similar distribution of IgD. TNFRSF14 expression pattern was of neoplastic B lymphocytes (centroblasts) and "tingible body macrophages". At diagnosis, the averages of total BTLA and TNFRSF14-positive cells were 19.2%±12.4STD (range, 0.6%-58.2%) and 46.7 cells/HPF (1-286.5), respectively. No differences were seen between low-grade vs. high-grade FL but tFL was characterized by low BTLA and high TNFRSF14 expression. High BTLA correlated with good overall survival (OS) (total-BTLA, Hazard Risk=0.479, P=0.022) and with high PD-1 and FOXP3+Tregs. High TNFRSF14 correlated with poor OS and progression-free survival (PFS) (total-TNFRSF14, HR=3.9 and 3.2, respectively, P<0.0001), with unfavorable clinical variables and higher risk of transformation (OR=5.3). Multivariate analysis including BTLA, TNFRSF14 and FLIPI showed that TNFRSF14 and FLIPI maintained prognostic value for OS and TNFRSF14 for PFS. In the GSE16131 FL series, high TNFRSF14 gene expression correlated with worse prognosis and GSEA showed that NFkB pathway was associated with the "High-TNFRSF14/dead-phenotype".In conclusion, the BTLA-TNFRSF14 immune modulation pathway seems to play a role in the pathobiology and prognosis of FL.

Primary cutaneous vs secondary cutaneous follicular lymphomas: A comparative study focused on BCL2, CD10, and t(14;18) expression.

BACKGROUND: Primary cutaneous follicular center-cell lymphoma (PCFCL) is one of the most common types of cutaneous B-cell lymphoma. Differences in immunohistochemical expression of BCL2 and CD10 antigens along with the presence of t(14:18) translocation in neoplastic cells have been postulated as relevant clues in differentiating PCFCL from cutaneous lesions secondary to a systemic follicular lymphoma (SCFL). The aim of this study is to evaluate the significance and usefulness of these parameters in a large series of patients. METHODS: Patients with PCFCL and SCFL diagnosed at three university hospitals in Barcelona, from 2000 to 2015 were reviewed. Clinical, histopathological, immunophenotypical, genetic, and outcome parameters were analyzed. RESULTS: Eighty-one cases (59 PCFCL and 22 SCFL) were included. There were no significant differences between PCFCL and SCFL cases regarding clinical presentation, site of involvement, or predominant type of skin lesions. Most patients in both groups showed positivity for BCL2 and CD10, but strong expression of BCL2 and CD10 was associated with SCFL cases. Although more frequent in SCFL, a small proportion of PCFCL cases also showed the t(14:18) on FISH analysis. CONCLUSION: The intensity of BCL2 expression was found to be the single most valuable clue in differentiating PCFCL from SCFL cases on histopathological grounds.

MicroRNAs 142-3p, miR-155 and miR-203 Are Deregulated in Gastric MALT Lymphomas Compared to Chronic Gastritis.

BACKGROUND: Over the last years, our knowledge on pathogenesis of gastric MALT lymphoma has greatly improved, but its morphological diagnosis is still hampered by overlapping histological features with advanced chronic gastritis. MicroRNAs are deregulated in lymphomas, but their role and usefulness in gastric MALT lymphoma has not been extensively investigated. MATERIALS AND METHODS: We analyzed the expression of 384 miRNAs using TaqMan microRNA assay in a training series of 10 gastric MALT lymphomas, 3 chronic gastritis and 2 reactive lymph nodes. Then, significantly deregulated miRNAs were individually assessed by real-time PCR in a validation series of 16 gastric MALT lymphomas and 12 chronic gastritis. RESULTS: Gastric MALT lymphoma is characterized by a specific miRNA expression profile. Among the differentially expressed miRNAs, a significant overexpression of miR-142-3p and miR-155 and down-regulation of miR-203 was observed in gastric MALT lymphoma when compared to chronic gastritis. CONCLUSION: miR-142-3p, miR-155 and miR-203 expression levels might be helpful biomarkers for the differential diagnosis between gastric MALT lymphomas and chronic gastritis.

Malaltia de Kikuchi-Fujimoto: presentació d'un cas pediàtric / Enfermedad de Kikuchi-Fujimoto: presentación de un caso pediátrico / Kikuchi-Fujimoto disease: a report of a pediatric case

Introducció: la malaltia de Kikuchi-Fujimoto, o limfadenitis necrosant histiocítica, és una patologia benigna poc freqüent que es caracteritza per clínica de febre i limfadenopatia cer-vical. Predomina en noies joves i habitualment sautolimita entre els 2 i els 4 mesos sense complicacions. Cas clínic: es presenta el cas duna pacient de 14 anys que presenta febre de tres dies devolució i adenopaties cervicals dretes. Les setmanes prèvies va presentar un quadre febril que es va autolimitar sense poder filiar-ne letiologia. Samplia lestudi amb proves complementàries, i es descarten amb lanalítica sanguínia i les proves dimatge les causes infeccioses o tumorals. Es fa exèresi quirúrgica duna adenopatia cervical amb intenció diagnosticotera-pèutica. Lestudi immunohistoquímic presenta característiques típiques de la limfadenitis necrosant histiocítica. La pacient presenta remissió de la simptomatologia i desaparició de les adenopaties. Comentaris: la limfadenitis necrosant histiocítica és una malaltia poc freqüent, però és important tenir-la en compte en pacients joves amb quadre febril i adenopaties de llarga evolució. La biòpsia del gangli per al diagnòstic definitiu és important per evitar altres proves o tractaments més agressius i innecessaris

Introducción. La enfermedad de Kikuchi-Fujimoto, o linfadenitis necrotizante histiocítica, es una patología benigna poco frecuente que se caracteriza por clínica de fiebre y linfadenopatía. Predomina en mujeres jóvenes y habitualmente se autolimita a los 2-4 meses sin presentar complicaciones. Caso clínico. Se presenta el caso de una paciente de 14 años que presenta fiebre de tres días de evolución y adenopatías cervicales derechas. Las semanas previas presentó cuadro febril que se autolimitó sin poder filiar su etiología. Se amplía el estudio con pruebas complementarias, descartando con la analítica sanguínea y las pruebas de imagen causas infecciosas o tumorales. Se realiza extirpación quirúrgica de una adenopatía cervical con intención diagnóstico-terapéutica. El estudio immunohistoquímico presenta características típicas de la linfadenitis necrotizante histiocítica. La paciente presenta remisión de la sintomatología y desaparición de las adenopatías. Comentarios. La linfadenitis necrotizante histiocítica es una enfermedad poco frecuente, pero es importante tenerla en cuenta en pacientes jóvenes con cuadro febril y adenopatías de larga evolución. La biopsia del ganglio para el diagnóstico definitivo es importante para evitar otras pruebas o tratamientos más agresivos e innecesarios (AU)

Introduction. Kikuchi-Fujimoto disease, or histiocytic necrotizing lymphadenitis, is a rare benign disease characterized by fever and lymphadenopathy. It mostly affects young women and it resolves spontaneously in 2-4 months without complications. Case report. A 14-year old female presented with a three-day history of fever and cervical lymphadenopathies. During the weeks prior to presentation, the patient had a self-limited febrile episode of unknown etiology. The laboratory and imaging evaluation ruled out a known infectious or neoplastic etiology. An excisional biopsy of a cervical node showed a pattern consistent with histiocytic necrotizing lymphadenitis. The symptoms and lymphadenopathies resolved in subsequent weeks. Comments. Although histiocytic necrotizing lymphadenitis is a rare disease, it should be considered in the diagnosis of young patients with longstanding fever and lymphadenopaties. Lymph node biopsy may provide definitive diagnosis while preventing other tests and more aggressive and unnecessary treatments (AU)

Definition of MYC genetic heteroclonality in diffuse large B-cell lymphoma with 8q24 rearrangement and its impact on protein expression.

MYC rearrangement can be detected in a subgroup of diffuse large B-cell lymphoma characterized by unfavorable prognosis. In contrast to Burkitt lymphoma, the correlation between MYC rearrangement and MYC protein expression in diffuse large B-cell lymphoma is less clear, as approximately one-third of rearranged cases show negative or low expression by immunohistochemistry. To better understand whether specific characteristics of the MYC rearrangement may influence its protein expression, we investigated 43 de novo diffuse large B-cell lymphoma positive for 8q24 rearrangement by FISH, using 14 Burkitt lymphoma for comparison. Different cell populations (clones), breakpoints (classical vs non-classical FISH patterns), partner genes (IGH vs non-IGH) and immunostaining were detected and analyzed using computerized image systems. In a subgroup of diffuse large B-cell lymphoma, we observed different clones within the same tumor distinguishing the founder clone with MYC rearrangement alone from other subclones, carrying MYC rearrangement coupled with loss/extra copies of derivatives/normal alleles. This picture, which we defined MYC genetic heteroclonality, was found in 42% of cases and correlated to negative MYC expression (P=0.026). Non-classical FISH breakpoints were detected in 16% of diffuse large B-cell lymphoma without affecting expression (P=0.040). Non-IGH gene was the preferential partner of rearrangement in those diffuse large B-cell lymphoma showing MYC heteroclonality (P=0.016) and/or non-classical FISH breakpoints (P=0.058). MYC heteroclonality was not observed in Burkitt lymphoma and all cases had positive MYC expression. Non-classical FISH MYC breakpoint and non-IGH partner were found in 29 and 20% of Burkitt lymphoma, respectively. In conclusion, MYC genetic heteroclonality is a frequent event in diffuse large B-cell lymphoma and may have a relevant role in modulating MYC expression.

Partial lack of BCL2 in follicular lymphoma: An unusual immunohistochemical staining pattern explained by ongoing BCL2 mutation.

Follicular lymphomas are characterized by overexpression of BCL2 which, in the large majority of cases, is due to a t(14;18) translocation which juxtaposes the BCL2 locus to the immunoglobulin heavy chain locus (IGH). Here, we report partial absence of BCL2 immunohistochemical staining in a case of FL, due to a mutation in the part of BCL2 that encodes the epitope for the most frequently used antibody against BCL2. This finding shows that mutations in BCL2 occur in an ongoing process in follicular which can give rise to unusual immunohistochemical staining patterns.

MYD88 L265P Mutations, But No Other Variants, Identify a Subpopulation of DLBCL Patients of Activated B-cell Origin, Extranodal Involvement, and Poor Outcome.

PURPOSE: Mutations in MYD88 are found in different lymphoproliferative disorders associated with particular biologic characteristics and clinical impact. The aim of this study was to analyze the incidence of MYD88 mutations and its clinical impact in diffuse large B-cell lymphoma (DLBCL). EXPERIMENTAL DESIGN: The incidence, clinicobiological features, and outcome of 213 patients (115 M/98 F; median age, 65 years) with DLBCL treated with immunochemotherapy in a single institution according to MYD88 mutational status as assessed by an allele-specific PCR assay were analyzed. The cell of origin (COO) was determined in 129 cases by gene expression. RESULTS: MYD88 mutations were found in 47 cases (22%), including L265P in 39 and S219C and M232F in 4 cases, respectively. Patients with MYD88 L265P were older, presenting frequent extranodal involvement, and mostly corresponded to activated B-cell like (ABC) subtype, whereas no preference in COO was observed in patients with other MYD88 mutations. Five-year overall survival (OS) for MYD88 wild-type, MYD88 L265P, and other variants was 62%, 52%, and 75%, respectively (P = 0.05). International Prognostic Index (IPI) (HR, 2.71; P < 0.001) and MYD88 L265P (HR, 1.786; P = 0.023) were independent variables predicting OS in the multivariate analysis. However, MYD88 L265P lost its independent value when COO was included in the model. CONCLUSIONS: Our findings indicate that MYD88 L265P mutations, but no other variants, identify a subgroup of DLBCL mainly of ABC origin, with extranodal involvement and poor outcome. Clin Cancer Res; 22(11); 2755-64. ©2016 AACR.

CD8-positive peripheral T-cell lymphoma with aberrant expression of CD20 and concurrent in situ follicular lymphoma.

A case of a 78-year-old woman with a CD8-positive peripheral T-cell lymphoma with aberrant expression of CD20 associated with follicular lymphoma in situ (FLIS) is reported. The neoplasm presented initially as cutaneous macules, papules, plaques and nodules. A skin biopsy was performed and the diagnosis of peripheral T-cell lymphoma (PTCl) with aberrant expression of CD20 was made. The staging procedures included an excisional inguinal lymph node biopsy that showed findings similar to those of the previous diagnosis. In addition, FLIS was identified. The clinicopathologic features of PTCLs with aberrant CD20 expression involving the skin as well as this uncommon association are reviewed.

Prognosis of patients with diffuse large B cell lymphoma not reaching complete response or relapsing after frontline chemotherapy or immunochemotherapy.

A retrospective study was performed to assess the outcome of patients with diffuse large B cell lymphoma (DLBCL) who did not achieve complete response or who relapsed before and after the use of rituximab. Clinical features and outcome of 816 (425 M/391 F; median age 63 years) patients diagnosed from 1991 to 2001 (pre-rituximab era, N = 348) and from 2002 to 2012 (rituximab era, N = 468) in a single institution were evaluated. Five hundred fifty-three patients achieved complete remission (CR), 57 partial response (PR), and 206 were refractory with a median overall survival of 15, 1.5, and 0.4 years, respectively. Patients receiving rituximab had lower risk of refractoriness or relapse. In primarily refractory and PR patients, there was not a difference in survival depending on whether patients received or not rituximab-containing frontline treatment. Early death rate was 11%, including 3.6% due to infectious complications. Rituximab did not modify these figures. In the relapse setting, 5-year survival from relapse was 25% for patients who never received rituximab, 54% for those who received rituximab only at relapse, and 48% for those treated with immunochemotherapy both as frontline and at relapse. In conclusion, relapsed/refractory patients with DLBCL show poor prognosis despite the use of frontline immunochemotherapy. New therapeutic approaches are needed in this group of patients.

Evaluation of unexplained peripheral lymphadenopathy and suspected malignancy using a distinct quick diagnostic delivery model: prospective study of 372 patients.

Although rapid diagnostic testing is essential in suspicious peripheral lymphadenopathy, delays in accessing them can be considerable. We investigated the usefulness of an internist-led outpatient quick diagnosis unit (QDU) in assessing patients with unexplained peripheral lymphadenopathy, focusing on the characteristics, diagnostic, and treatment waiting times of those with malignancy. Patients aged ≥ 18 years, consecutively referred from 12 primary health care centers (PHCs) or the emergency department (ED) for unexplained peripheral lymphadenopathy, were prospectively evaluated during 7 years. Diagnostic investigations were done using a predefined study protocol. Three experienced cytopathologists performed a fine-needle aspiration cytology (FNAC) systematic approach of clinically suspicious lymphadenopathy with cytomorphology and immunophenotyping analyses. We evaluated 372 patients with a mean age (SD) of 45.3 (13.8) years; 56% were women. Malignancy was diagnosed in 120 (32%) patients, including 81 lymphomas and 39 metastatic tumors. Metastatic lymphadenopathy was diagnosed by FNAC in all 39 patients and the primary tumor site was identified in 82% of them when cytomorphology and immunocytochemistry were combined. A correct diagnosis of lymphoma was reached by FNAC in 73% of patients. When accepting "suspicious of" as correct diagnosis, the FNAC diagnosis rate of lymphoma increased to 94%. Among patients with malignancy, FNAC yielded 1.3% of false negatives and no false positives. All patients with an FNAC report of correct or suspicious lymphoma underwent a surgical biopsy, as it is a mandatory requirement of the hematology department. Mean times from first QDU visit to FNAC diagnosis of malignancy were 5.4 days in metastatic lymphadenopathy and 7.5 days in lymphoma. Mean times from receiving the initial referral report to first treatment were 29.2 days in metastatic lymphadenopathy and 40 days in lymphoma. In conclusion, a distinct internal medicine QDU allows an expeditious, agile, and prearranged system to diagnose malignant peripheral lymphadenopathy. Because of the close collaboration with the cytopathology unit and the FNAC methodical approach, diagnostic and treatment waiting times of patients with malignancy fulfilled national and international time frame standards. This particular diagnostic delivery unit could help overcome the difficulties facing PHC, ED, and other physicians when trying to provide rapid access to investigations to patients with troublesome lymphadenopathy.