Diffuse large B cell lymphoma derived from nodular lymphocyte predominant Hodgkin lymphoma presents with variable histopathology

Targeting neutrophil extracellular traps: A novel strategy in hematologic malignancies

Neutrophil extracellular traps (NETs) have emerged as a critical factor in malignant hematologic disease pathogenesis. These structures, comprising DNA, histones, and cytoplasmic proteins, were initially recognized for their role in immune defense against microbial threats. Growing evidence suggests that NETs contribute to malignant cell progression and dissemination, representing a double-edged sword. However, there is a paucity of reports on its involvement in hematological disorders. A comprehensive understanding of the intricate relationship between malignant cells and NETs is necessary to explore effective therapeutic strategies. This review highlights NET formation and mechanisms underlying disease pathogenesis. Moreover, we discuss recent advancements in targeted inhibitor development for selective NET disruption, empowering precise design and efficacious therapeutic interventions for malignant hematologic diseases.

Meningeal Relapse of Nodular Lymphocyte Predominant Hodgkin Lymphoma Transformed to T-Cell/Histiocyte-Rich Large B-Cell Lymphoma: A Case Report

Central nervous system involvement in Hodgkin lymphoma is extremely rare, especially in nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), which usually carries a favorable prognosis. Here we report a case of a young patient with NLPHL, who developed a progressive and fatal neurological deterioration requiring a very extensive work-up including two biopsies to obtain the diagnosis of T-cell/histiocyte-rich large B-cell lymphoma like transformation. This report, which includes post-mortem analysis, highlights the correlations between clinical, radiological, and biological data but also the difficulties encountered in reaching the correct diagnosis.

Diagnosis of Hodgkin lymphoma in the modern era

The Hodgkin lymphomas are a family of unique lymphoma subtypes, in which the nature of the neoplastic cell was enigmatic for many years. Much of the mystery has been solved, with all forms now considered to be of B-cell origin, in most cases of germinal centre derivation. Today we recognize Hodgkin lymphoma as an eponym that encompasses multiple entities. One of the unifying themes is the major contribution from the tumour microenvironment. Both the character of the neoplastic cells and the nature of the immune environment are critical to accurate diagnosis. Moreover, an understanding of the molecular alterations that characterize both the neoplastic cells and their microenvironment have led to therapeutic advances, targeting both neoplastic and reactive components. Other conditions may foster a similar inflammatory milieu and lead to lymphoproliferations that mimic the Hodgkin lymphomas. In this review we provide an update on the diagnostic features of the various subtypes and include additional information relevant for prognostic evaluation and investigation of potential therapeutic targets. Additionally, we also discuss those conditions that often cause confusion in diagnosis and need to be distinguished from the Hodgkin lymphomas.

A strong host response and lack of MYC expression are characteristic for diffuse large B cell lymphoma transformed from nodular lymphocyte predominant Hodgkin lymphoma

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is an indolent lymphoma, but can transform into diffuse large B cell lymphoma (DLBCL), showing a more aggressive clinical behavior. Little is known about these cases on the molecular level. Therefore, the aim of the present study was to characterize DLBCL transformed from NLPHL (LP-DLBCL) by gene expression profiling (GEP). GEP revealed an inflammatory signature pinpointing to a specific host response. In a coculture model resembling this host response, DEV tumor cells showed an impaired growth behavior. Mechanisms involved in the reduced tumor cell proliferation included a downregulation of MYC and its target genes. Lack of MYC expression was also confirmed in 12/16 LP-DLBCL by immunohistochemistry. Furthermore, CD274/PD-L1 was upregulated in DEV tumor cells after coculture with T cells or monocytes and its expression was validated in 12/19 cases of LP-DLBCL. Thereby, our data provide new insights into the pathogenesis of LP-DLBCL and an explanation for the relatively low tumor cell content. Moreover, the findings suggest that treatment of these patients with immune checkpoint inhibitors may enhance an already ongoing host response in these patients.

High dose chemotherapy and autologous stem cell transplantation in nodular lymphocyte-predominant Hodgkin lymphoma: A retrospective study by the European society for blood and marrow transplantation-lymphoma working party

Whilst autologous stem cell transplantation (auto-SCT) is considered standard of care for relapsed/refractory classical Hodgkin lymphoma, the role of auto-SCT in nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is not well defined due to limited data. We report the first study on auto-SCT for NLPHL with a larger cohort. Eligible for this retrospective registry study were patients reported to the EBMT between 2003 and 2013, aged 18 or older with relapsed/refractory NLPHL who underwent first auto-SCT with disease chemosensitive to salvage therapy. NLPHL transformed to diffuse large B cell lymphoma were excluded. Sixty patients (83% male; median age 40 years) met the eligibility criteria. The median time between diagnosis and transplant was 21 months (IQR 13-58), and the median number of prior treatment lines was 2 (range 1-5), including rituximab in 63% of the patients. At auto-SCT, 62% of the patients were in complete remission (CR) and 38% in partial remission. Seventy-two percent of the patients received BEAM as high-dose therapy. With a median follow-up of 56 months (range 3-105), 5-year progression-free and overall survival (OS) were 66% and 87%, respectively. Univariate comparisons considering age, time from diagnosis to transplant, prior chemotherapy lines, and prior rituximab use failed to identify significant predictors for any survival endpoint except for being in CR at the time of auto-SCT (vs PR, P = .049) for OS. Auto-SCT in patients with relapsed/refractory NLPHL who are sensitive to salvage therapy gives excellent disease control and long-term survival independent of the time interval between diagnosis and transplant.

[Update on nodular lymphocyte predominant Hodgkin's lymphoma and related lesions]

The present article gives an overview of novel developments in the diagnosis of nodular lymphocyte predominant Hodgkin's lymphoma with reference to the revised WHO classification from 2016. Differential diagnoses that are discussed are progressively transformed germinal centers, T cell/histiocyte-rich large B cell lymphoma as well as transformation into a diffuse large B cell lymphoma.

High-dose chemotherapy and autologous stem cell transplantation for relapsed or refractory nodular lymphocyte predominant Hodgkin lymphoma

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a distinct subtype of Hodgkin lymphoma. We report our results of relapsed/refractory NLPHL patients who received high-dose chemotherapy and autogenic stem cell transplantation (HDC auto-SCT). Seventeen NLPHL patients received HDC auto-SCT (1996–2014): male 14 and female 3, with median age at diagnosis of 22 years, at HDC auto-SCT 28 years (15–58 years). At the time of relapse/progression, 13 (76 %) had NLPHL and 4 (24 %) had transformed diffuse large B cell lymphoma. The reason for HDC auto-SCT was refractory NLPHL in 12 patients and relapsed in 5 patients. Salvage chemotherapy was etoposide, methylprednisolone, cisplatinum, and Ara-C (ESHAP); eight patients also received rituximab with ESHAP. HDC was carmustine, etoposide, cytarabine, and melphalan (BEAM). Post-auto-SCT, complete remission was achieved in 14 (82 %), partial remission in 1 (6 %), and progressive disease in 2 (12 %) patients. The median follow-up is 63 months from auto-SCT (6–124 months). Of the nine patients who received only ESHAP, four had post-auto-SCT events versus no event in all eight patients who received rituximab+ESHAP. Kaplan–Meier estimates of 5-year event-free survival for the whole group is 76 %: rituximab+salvage (100 %) versus salvage alone (56 %), P=0.041. Overall survival is 94 %: 100 versus 89 %, respectively, P=not significant (NS). Even in refractory NLPHL patients, long-term disease-free survival is possible after HDC auto-SCT. Post-auto-SCT relapse or progression can still be managed with chemo/chemo+immunotherapy/ radiation. These encouraging results of rituximab in salvage setting should be explored further in a clinical trial setting for this patient population.

Large B-cell transformation in nodular lymphocyte-predominant Hodgkin lymphoma: 40-year experience from a single institution

A number of reports have shown a propensity of nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) to transform into diffuse large B-cell lymphoma (DLBCL). Long-term data on the incidence and outcomes of transformed NLPHL are lacking. A comprehensive analysis of the actively maintained Mayo Clinic Lymphoma Database was performed. Between 1970 and 2011, 222 consecutive adult patients with new untreated NLPHL were identified. Median age at diagnosis was 40 years, and 146 (66%) were males. The median follow-up was 16 years. Seventeen patients (7.6%) developed a transformation to DLBCL. The median time to transformation was 35 months (range, 6-268 months). Based on the observed 17 transformations during 2304 patient-years of follow-up, the rate of transformation was 0.74 per 100 patient-years. In a multivariate analysis, use of any prior chemotherapy ( ITALIC! P= .04) and splenic involvement ( ITALIC! P= .03) were significantly associated with increased risk of transformation. The 5-year overall survival (OS) in those with transformed disease was 76.4%, and transformation did not adversely affect OS when compared with patients who did not experience transformation. In this large single-institution cohort with long-term follow-up, the risk of transformation was lower than that observed in other low-grade lymphomas.

Nodular lymphocyte predominant Hodgkin lymphoma: Clincopathological study of 25 cases from Japan with a reappraisal of tissue associated macrophages

Clinicopathological features of 25 nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) patients in Japan were analysed. To investigate the clinicopathological significance of tissue associated macrophages (TAM) in NLPHL, CD68 and CD163 expression were investigated. The median age at onset was 56 years (range: 6-82 years) with male predominance (64%). All patients presented with lymph node enlargement with predilection for cervical LNs. Seven cases (28%) had mediastinal lesion and four (16%) had extranodal involvement. Most cases (76%) presented with early clinical stages. After median follow up of 44 months, both of overall and progression free survival rates were 95%. The presence of >5% CD68+ TAM in NLPHL was significantly associated with older age at diagnosis (median, 71 vs 52.5 years; P = 0.048), lower hemoglobin level (33.3% vs 0%; P = 0.037) and lower CR rate after initial treatment (42.9% vs 91.7%; P = 0.038). The presence of >5% CD163+ TAM was significantly correlated with presence of B symptoms (40% vs 0%; P = 0.036). In conclusion, NLPHL is rare among Japanese and appears to present at an older age than among Western patients. In our series, the presence of >5% CD68+ TAM in NLPHL was associated with lower CR rate, but with no impact on patients' survival.

BCL6--regulated by AhR/ARNT and wild-type MEF2B--drives expression of germinal center markers MYBL1 and LMO2

Genetic heterogeneity is widespread in tumors, but poorly documented in cell lines. According to immunoglobulin hypermutation analysis, the diffuse large B-cell lymphoma cell line U-2932 comprises two subpopulations faithfully representing original tumor subclones. We set out to identify molecular causes underlying subclone-specific expression affecting 221 genes including surface markers and the germinal center oncogenes BCL6 and MYC. Genomic copy number variations explained 58/221 genes differentially expressed in the two U-2932 clones. Subclone-specific expression of the aryl-hydrocarbon receptor (AhR) and the resulting activity of the AhR/ARNT complex underlaid differential regulation of 11 genes including MEF2B. Knock-down and inhibitor experiments confirmed that AhR/ARNT regulates MEF2B, a key transcription factor for BCL6. AhR, MEF2B and BCL6 levels correlated not only in the U-2932 subclones but in the majority of 23 cell lines tested, indicting overexpression of AhR as a novel mechanism behind BCL6 diffuse large B-cell lymphoma. Enforced modulation of BCL6 affected 48/221 signature genes. Although BCL6 is known as a transcriptional repressor, 28 genes were up-regulated, including LMO2 and MYBL1 which, like BCL6, signify germinal center diffuse large B-cell lymphoma. Supporting the notion that BCL6 can induce gene expression, BCL6 and the majority of potential targets were co-regulated in a series of B-cell lines. In conclusion, genomic copy number aberrations, activation of AhR/ARNT, and overexpression of BCL6 are collectively responsible for differential expression of more than 100 genes in subclones of the U-2932 cell line. It is particularly interesting that BCL6 - regulated by AhR/ARNT and wild-type MEF2B - may drive expression of germinal center markers in diffuse large B-cell lymphoma.

The survival decrease in gastric cancer is associated with the methylation of B-cell CLL/lymphoma 6 member B promoter

The methylation of B-cell CLL/lymphoma 6 member B (BCL6B) DNA promoter was detected in several malignancies. Here, we quantitatively detect the methylated status of CpG sites of BCL6B DNA promoter of 459 patients with gastric cancer (GC) by using bisulfite gene sequencing. We show that patients with three or more methylated CpG sites in the BCL6B promoter were significantly associated with poor survival. Furthermore, by using the Akaike information criterion value calculation, we show that the methylated count of BCL6B promoter was identified to be the optimal prognostic predictor of GC patients.