Clinicopathologic consensus study of gray zone lymphoma with features intermediate between DLBCL and classical HL

Gray zone lymphoma (GZL) is described as sharing features with classical Hodgkin lymphoma (cHL) and diffuse large B-cell lymphoma (DLBCL). However, there remains complexity in establishing diagnosis, delineating prognosis, and determining optimum therapy. Sixty-eight cases diagnosed as GZL across 15 North American academic centers were evaluated by central pathology review to achieve consensus. Of these, only 26 (38%) were confirmed as GZL. Morphology was critical to GZL consensus diagnosis (eg, tumor cell richness); immunohistochemistry showed universal B-cell derivation, frequent CD30 expression, and rare Epstein-Barr virus (EBV) positivity (CD20(+), 83%; PAX5(+), 100%; BCL6(+), 20%; MUM1(+), 100%; CD30(+), 92%; EBV(+), 4%). Forty-two cases were reclassified: nodular sclerosis (NS) cHL, n = 27 (including n = 10 NS grade 2); lymphocyte predominant HL, n = 4; DLBCL, n = 4; EBV(+) DLBCL, n = 3; primary mediastinal large BCL n = 2; lymphocyte-rich cHL and BCL-not otherwise specified, n = 1 each. GZL consensus-confirmed vs reclassified cases, respectively, more often had mediastinal disease (69% vs 41%; P = .038) and less likely more than 1 extranodal site (0% vs 25%; P = .019). With a 44-month median follow-up, 3-year progression-free survival (PFS) and overall survival for patients with confirmed GZL were 39% and 95%, respectively, vs 58% and 85%, respectively, for reclassified cases (P = .19 and P = .15, respectively). Interestingly, NS grade 2 reclassified patients had similar PFS as GZL consensus-confirmed cases. For prognostication of GZL cases, hypoalbuminemia was a negative factor (3-year PFS, 12% vs 64%; P = .01), whereas frontline cyclophosphamide, doxorubicin, vincristine, and prednisone +/- rituximab (CHOP+/-R) was associated with improved 3-year PFS (70% vs 20%; P = .03); both factors remained significant on multivariate analysis. Altogether, accurate diagnosis of GZL remains challenging, and improved therapeutic strategies are needed

The Genetic Basis of Hepatosplenic T-cell Lymphoma

Hepatosplenic T cell lymphoma (HSTL) is a rare and lethal lymphoma; the genetic drivers of this disease are unknown. Through whole exome sequencing of 68 HSTLs, we define recurrently mutated driver genes and copy number alterations in the disease. Chromatin modifying genes including SETD2, INO80 and ARID1B were commonly mutated in HSTL, affecting 62% of cases. HSTLs manifest frequent mutations in STAT5B (31%), STAT3 (9%), and PIK3CD (9%) for which there currently exist potential targeted therapies. In addition, we noted less frequent events in EZH2, KRAS and TP53. SETD2 was the most frequently silenced gene in HSTL. We experimentally demonstrated that SETD2 acts as a tumor suppressor gene. In addition, we found that mutations in STAT5B and PIK3CD activate critical signaling pathways important to cell survival in HSTL. Our work thus defines the genetic landscape of HSTL and implicates novel gene mutations linked to HSTL pathogenesis and potential treatment targets

Primary Hairy Cell Leukemia/Lymphoma of the Breast: A Case Report and Review of the Literature

Hairy cell leukemia/lymphoma (HCL) is a rare B-cell neoplasm primarily involving spleen, bone marrow, and blood. However, other sites of primary involvement do occur and can present a diagnostic and therapeutic challenge. We present an unusual case of HCL involving predominantly the breast that was diagnosed as an incidental finding during an elective reduction mammoplasty in an otherwise healthy asymptomatic woman. Bone marrow performed for staging revealed limited involvement by HCL. Notably, there was no splenomegaly and/or involvement of other extramedullary sites. The peripheral blood revealed minimal involvement detected by flow cytometry. Extensive immunohistochemical studies supported by positive BRAF V600E mutational status confirmed the diagnosis of HCL. The patient remains asymptomatic without treatment one year following the diagnosis. This is the first case of a well-documented HCL presenting primarily in the breast in an asymptomatic patient. We review the literature on extramedullary, extrasplenic involvement by HCL and discuss the diagnostic challenges as well as the utility of immunohistochemistry and molecular studies in the diagnosis of atypical presentations of HCL

Secondary pulmonary alveolar proteinosis in hematologic malignancies

Pulmonary alveolar proteinosis (PAP), characterized by deposition of intra-alveolar PAS positive protein and lipid rich material, is a rare cause of progressive respiratory failure first described by Rosen et al. in 1958. The intra-alveolar lipoproteinaceous material was subsequently proven to have been derived from pulmonary surfactant in 1980 by Singh et al. Levinson et al. also reported in 1958 the case of 19-year-old female with panmyelosis afflicted with a diffuse pulmonary disease characterized by filling of the alveoli with amorphous material described as “intra-alveolar coagulum”. This is probably the first reported case of PAP in relation to hematologic malignancy. Much progress has been made on PAP first described by Rosen which is currently classified as idiopathic or primary or autoimmune PAP. Idiopathic PAP occurs as a result of auto-antibodies directed against granulocyte–macrophage colony stimulating factor (GM-CSF) impeding the surfactant clearing function of alveolar macrophages leading to progressive respiratory failure. Whole lung lavage and GM-CSF therapy has improved outcomes in patients with idiopathic PAP. Despite major advancement in the management of hematologic malignancy and its complications, little is known about the type of PAP first described by Levinson and now known as secondary PAP; a term also used when PAP occurs due to other causes such as occupational dusts. In this article we review and analyze the limited literature available in secondary PAP due to hematologic malignancies and present a case of PAP associated with chronic lymphocytic leukemia successfully treated with bendamustine and rituximab. Keywords: Secondary pulmonary alveolar proteinosis, Hematologic malignancy, Bronchoalveolar lavage, Opportunistic infections, Hematopoietic stem cell transplantatio

Proteolytic fragments of fibronectin function as matrikines driving the chemotactic affinity of prostate cancer cells to human bone marrow mesenchymal stromal cells via the α5β1 integrin

<p>The haematopoietic niche is contributed to by bone marrow-resident mesenchymal stromal cells (BM-MSCs) and subverted by prostate cancer cells. To study mechanisms by which BM-MSCs and prostate cancer cells may interact, we assessed the migration, invasion, adhesion and proliferation of bone-derived prostate cancer cells (PC-3) in co-culture with pluripotent human BM-MSCs. We observed a strong adhesive, migratory and invasive phenotype of PC-3 cells with BM- MSC-co-culture and set out to isolate and characterize the bioactive principle. Initial studies indicated that chemotaxis was secondary to a protein residing in the >100kDa fraction. Size-exclusion chromatography (SEC) recovered peak activity in a high-molecular weight fraction containing thrombospondin-1 (TSP1). While TSP1 immunodepletion decreased activity, put-back with purified TSP1 did not reproduce bioactivity. Further purification of the TSP1-containing high-molecular weight fraction of the BM-MSC secretome with heparin-affinity chromatography recovered bioactivity with highly restricted bands on polyacrylamide gel electrophoresis, determined by mass spectroscopy to be proteolytic fragments of fibronectin (FN). Put-back experiments with full-length FN permitted adhesion but failed to induce migration. Monospecific antibodies to FN blocked adhesion. Proteolytic cleavage of FN generated FN fragments which now induced migration. Neutralizing monoclonal antibodies to FN receptors α5 and β1 integrins, and α5 knockdown specifically blocked migration and adhesion. Conclusion: Fibronectin fragments (FNFr) function as matrikines driving the chemotactic affinity of prostate cancer cells via the α5β1 integrin. Taken together with the high-frequency of α5β1 expression in disseminated prostate cancer cells in bone marrow aspirates from patients, the FNFr/FN-α5β1 interaction warrants further study as a therapeutic target.</p

Accelerated Systemic Autoimmunity in the Absence of Somatic Hypermutation in 564Igi: A Mouse Model of Systemic Lupus with Knocked-In Heavy and Light Chain Genes

564Igi mice have knocked-in immunoglobulin (Ig) heavy (H) and light (L) chain genes that encode an autoantibody recognizing RNA. Previously, we showed that these mice produce pathogenic IgG autoantibodies when activation-induced deaminase (AID) is expressed in pre-B and immature B cells but not when it is expressed only in mature B cells. AID has two functions; it is necessary for somatic hypermutation (SHM) and class switch recombination (CSR). To determine the role of each of these functions in the generation of pathogenic autoantibodies, we generated 564Igi mice that carry a mutant AID-encoding gene, Aicda (AicdaG23S), which is capable of promoting CSR but not SHM. We found that 564Igi AicdaG23S mice secreted class-switched antibodies (Abs) at levels approximately equal to 564Igi mice. However, compared to 564Igi mice, 564Igi AicdaG23S mice had increased pathogenic IgG Abs and severe systemic lupus erythematosus-like disease, including, glomerulonephritis, and early death. We suggest that in 564Igi mice SHM by AID changes Ig receptors away from self reactivity, thereby mitigating the production of autoantibody, providing a novel mechanism of tolerance

Resistance Training Increases Muscle Mitochondrial Biogenesis in Patients with Chronic Kidney Disease

Background and objectives: Muscle wasting, a common complication in chronic kidney disease (CKD), contributes to poor outcomes. Mitochondrial biogenesis is critical for the maintenance of skeletal muscle function and structural integrity. The present study—a secondary analysis from a published randomized controlled trial—examined the effect of resistance exercise training on skeletal muscle mitochondrial (mt)DNA copy number and determined its association with skeletal muscle phenotype (muscle mass and strength)

Gray Zone Lymphoma (GZL) with Features Intermediate Between Diffuse Large B-Cell Lymphoma (DLBCL) and Classical Hodgkin Lymphoma (cHL): Pathologic Classification and Clinical Outcomes from a Multicenter Consensus Study

Abstract BACKGROUND: GZL (B-cell lymphoma, unclassifiable, with features intermediate between DLBCL andcHL) was first described in 2005 and included in the 2008 WHO classification. The majority of cases present withmediastinal disease and share features withcHL and primarymediastinal large B-cell lymphoma (PMBCL). Non-mediastinal lymphomas with similar features have also been reported. Due to the relative rarity and the diagnostic complexity of this disease, data on GZL are limited and further description of this entity is desired. METHODS: Clinical data from cases originally diagnosed as GZL were collected from 15 academic centers across the United States and Canada (Evens et al. Am J Hematol, 2015). In an attempt to further characterize the diagnostic features and clinical correlations, 73 cases (including 62 cases from the aforementioned series and 11 subsequently collected cases) were obtained and submitted for central pathology review using criteria of the 2016 revisedWHO classification. All diagnostic samples were evaluated with a panel comprising CD20, CD79a, PAX5, OCT2, BCL6, MUM1, CD30, CD15, CD3 and EBV by in situ hybridization (EBER). Beyond the tumor cellimmunoprofile, diagnostic criteria included: tumor cell density and morphology, necrosis, and the microenvironment. Five cases were rejected for insufficient material/technical issues. Collectively, 68 cases were evaluated by 5 experthematopathologists and consensus diagnosis was reached at multi-headed scope review. Additionally, clinical data were obtained to analyze patient (pt) characteristics and disease outcomes. RESULTS: Of 68 cases given an original diagnosis of GZL from academic institutions, only 26 cases (38%) were confirmed as GZL on consensus review. Pt characteristics of these 26 GZL cases included: 15M/11F; median age 37 years (range 19-72); 42% B symptoms; 61% anemia; 35% increased LDH; and 33% with hypoalbuminemia. 11/26 (42%) biopsies were mediastinal in origin, and in an additional 4 cases, a mediastinal mass was present clinically; 11 (42%) had only peripheral lymphadenopathy/disease (ie, non-mediastinal). 60% of pts had stage I/II disease with 16% having stage IV. GZL cases were characterized by high tumor cell density and paucity of a mixed inflammatory background (both contrary as seen in cHL). The immunohistochemical profiles of the 26 consensus GZL cases are noted in the Table. Notably, only 1 GZL case was EBV positive. 42/68 (62%) of the original cases were reclassified as follows: nodular sclerosis (NS)cHL, n=27 [n=10 of which werecHL, NS grade 2 (cHL-NS2)] and one lymphocyte-richcHL (LRCHL), n=1; DLBCL NOS, n=4; PMBCL, n=2; nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), n=3; EBV positive LBCL, n=3; and B-cell lymphoproliferative disorder, n=1. Most cases ofcHL diagnosed as GZL had strong CD20 expression. Further, cHL-NS2 was often misdiagnosed as GZL usually due to confluent growth of lacunar cells. Clinically, therapy received and outcomes were available for 25 of 26 of the aforementioned consensus GZL cases; the overall response rate (ORR) for these consensus confirmed GZL cases was 64% (complete remission (CR) 48%) with 28% ofpts experiencing primary refractory disease to frontline therapy. Relapse rates by primary chemotherapy regimen for thesepts were: ABVD 5/6 (83%); CHOP 7/17 (41%); and EPOCH 1/2 (50%). Among consensus GZLpts with relapsed disease, 71% underwent autologous SCT. With a median follow-up of 40 months, the 3-year PFS was 44% with 3-year OS of 90% for the consensus GZL pts. Among all other cases that were reclassified to a non-GZL diagnostic entity, the ORR was 75% (CR 67%) with 3-year PFS and OS rates of 52% and 80%, respectively. This included a relapse rate of 86% amongpts with cHL-NS2. CONCLUSIONS: Accurate diagnosis of GZL remains challenging. Relative rarity of the cases and overlap withcHL, especially thecHL-NS variant with lymphocytic depletion and confluent lacunar cells (also known as cHL-NS2), contribute to this difficulty. Diagnosis should be based on integration of architectural, cytological andimmunophenotypic features. In addition, relapse rates are high with standard chemotherapy regimens, especially ABVD-based therapy. Enhanced biologic understanding and improved therapeutic strategies are needed for GZL. Disclosures Evens: Takeda: Other: Advisory board. Abramson:Abbvie: Consultancy; Gilead: Consultancy; Seattle Genetics: Consultancy; Kite Pharma: Consultancy. Fenske:Celgene: Honoraria; Millennium/Takeda: Research Funding; Pharmacyclics: Honoraria; Seatle Genetics: Honoraria. Friedberg:Bayer: Honoraria, Other: Data Safety Monitoring Board. Blum:Pharmacyclics: Research Funding