Childhood and Adolescent nodular lymphocyte predominant Hodgkin lymphoma - A review of clinical outcome based on the histological variants

T-Cell-Rich Hodgkin Lymphoma With Features of Classic Hodgkin Lymphoma and Nodular Lymphocyte-Predominant Hodgkin Lymphoma: A Borderline Category With Overlapping Morphologic and Immunophenotypic Features

CONTEXT.—

It is known that a subset of cases of classic Hodgkin lymphoma (CHL) with B-cell-rich nodules (lymphocyte-rich CHL) exhibits morphologic and immunophenotypic features that overlap with nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), raising diagnostic difficulties that can be resolved in most cases by performing an adequate battery of immunohistochemical studies.

OBJECTIVE.—

To fully characterize cases of T-cell-rich Hodgkin lymphoma where a specific diagnosis of NLPHL (ie, pattern D) or CHL could not be made even after complete immunophenotypic investigation.

DESIGN.—

The clinical, immunomorphologic, and molecular (when applicable) presentation of 3 cases of T-cell-rich Hodgkin lymphoma was thoroughly investigated.

RESULTS.—

These 3 cases harbored lymphocyte-predominant-like and Hodgkin and Reed-Sternberg-like cells that partially expressed B-cell and CHL markers and were negative for Tiftein-Barr virus-encoded small RNA, in a T-cell-rich background with residual follicular dendritic cell meshworks; 1 case had frequent and the other 2 cases scant/absent eosinophils and plasma cells. Two patients with advanced-stage (III or IV) disease presented with axillary and supraclavicular lymphadenopathy, respectively, and without B symptoms. These patients underwent NLPHL-like therapeutic management with 6 cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin hydrochloride [hydroxydaunorubicin], vincristine sulfate [Oncovin], and prednisone) chemotherapy; both are in complete remission 7 years posttherapy. One patient presented with stage I disease involving an internal mammary lymph node without B-symptoms and was treated with surgical excision alone; this patient is also in complete remission 1 year later.

CONCLUSIONS.—

These cases illustrate overlapping features of T-cell-rich NLPHL and CHL with neoplastic cells expressing both B-cell program and CHL markers. This underrecognized overlap has not been fully illustrated in the literature, although it portrays a therapeutic challenge. These neoplasms may deserve in-depth investigation in the future that may bring up diagnostic or theragnostic implications.

International Prognostic Score for Nodular Lymphocyte-Predominant Hodgkin Lymphoma

PURPOSE

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare cancer, and large international cooperative efforts are needed to evaluate the significance of clinical risk factors and immunoarchitectural patterns (IAPs) for all stages of pediatric and adult patients with NLPHL.

METHODS

Thirty-eight institutions participated in the Global nLPHL One Working Group retrospective study of NLPHL cases from 1992 to 2021. We measured progression-free survival (PFS), overall survival (OS), transformation rate, and lymphoma-specific death rate. We performed uni- and multivariable (MVA) Cox regression stratified by management to select factors for the lymphocyte-predominant international prognostic score (LP-IPS) validated by five-fold cross-validation.

RESULTS

We identified 2,243 patients with a median age of 37 years (IQR, 23-51). The median follow-up was 6.3 years (IQR, 3.4-10.8). Most had stage I to II (72.9%) and few B symptoms (9.9%) or splenic involvement (5.4%). IAP was scored for 916 (40.8%). Frontline management included chemotherapy alone (32.4%), combined modality therapy (30.5%), radiotherapy alone (24.0%), observation after excision (4.6%), rituximab alone (4.0%), active surveillance (3.4%), and rituximab and radiotherapy (1.1%). The PFS, OS, transformation, and lymphoma-specific death rates at 10 years were 70.8%, 91.6%, 4.8%, and 3.3%, respectively. On MVA, IAPs were not associated with PFS or OS, but IAP E had higher risk of transformation (hazard ratio [HR], 1.81; P < .05). We developed the LP-IPS with 1 point each for age ≥45 years, stage III-IV, hemoglobin <10.5 g/dL, and splenic involvement. Increasing LP-IPS was significantly associated with worse PFS (HR, 1.52) and OS (HR, 2.31) and increased risk of lymphoma-specific death (HR, 2.63) and transformation (HR, 1.41).

CONCLUSION

In this comprehensive study of all ages of patients with NLPHL, we develop the LP-IPS to identify high-risk patients and inform upcoming prospective clinical trials evaluating de-escalation of therapy for patients with low LP-IPS scores (<2).

[IgD expression in various immunoarchitectural patterns of nodular lymphocyte predominant Hodgkin lymphoma in children]

BACKGROUND

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) consist of lymphocyte predominant cell or LP-cell. Despite their origin from active germinal centers, in some cases LP-cells express IgD, which is characteristic of naive B-lymphocytes of the mantle zone. Due to the rarity of NLPHL, assessing the frequency of IgD-positive cases is difficult. This marker can serve not only for differential diagnosis with other diseases, but also indicate the possible heterogeneity of NLPHL, which is currently represented by six immunoarchitectural patterns.

OBJECTIVE

To determine the frequency of IgD-positive cases of NLPHL in children with subsequent assessment of the association with types of immunoarchitectural patterns.

MATERIAL AND METHODS

The study included 52 cases of NLPHL, which were divided to typical and atypical patterns. Differences between two groups were compared using Fisher's exact tests.

RESULTS

IgD expression was found in LP-cells in 26 of 52 cases (50%) and was positively correlated with atypical types (typical - 5/23, 21.7% vs atypical - 21/29, 72.4%, p=0.0003), among which pattern C was most common.

CONCLUSION

Due to the high incidence of IgD-positive cases in NLPHL, this marker may be useful in differential diagnosis with histologic mimics. At the same time, positive IgD status was associated with atypical patterns, which may likely determine the different biology of neoplastic cells within the same form.

Variant histology of pediatric nodular lymphocyte-predominant Hodgkin lymphoma with IgD and CD30 expression

BACKGROUND

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), recently known as nodular lymphocyte-predominant B-cell lymphoma (NLPBL), accounts for 5%-10% of Hodgkin lymphoma (HL). Different morphologic patterns of NLPBL are identified and categorized as typical patterns (type A and B) and variant histologic patterns (types C, D, E, and F).

PATIENTS AND METHOD

We investigated different morphologic patterns, CD30 and IgD expression in pediatric patients with NLPBL diagnosed at the Children's Cancer Hospital Egypt.

RESULTS

Forty-six (53%) of the patients exhibited a typical histologic pattern, whereas the remaining (47%) exhibited variant histologic pattern. Variant histology is associated with unfavorable clinical characteristics, such as advanced stages, B-symptoms, and extranodal involvements, particularly bone marrow and bone infiltration, with p-values of .06, .05, and 0.01%, respectively. Additionally, 39% of patients with variant histology experienced disease progression or relapse, compared to only 15.2% of patients with typical patterns (p = .009). Types C and D are related to decreased event-free survival (EFS), as shown by a p-value of .05. The 5-year EFS for patients with variant histology was 94.4% for the rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisone (RCHOP) versus 33.3% for the adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD). IgD expression in lymphocyte-predominant (LP) cells was detected in 44 (50%) patients, while CD30 expression in LP cells was found in 39 (44%) patients.

CONCLUSION

Variant histology of NLPBL was associated with advanced disease stages and a poor prognosis, while expression of IgD and CD30 in LP cells was not. The poor outcome of variant histology improved with the RCHOP regimen.

Microenvironmental immune cell alterations across the spectrum of nodular lymphocyte predominant Hodgkin lymphoma and T-cell/histiocyte-rich large B-cell lymphoma

Background

The clinicopathological spectrum of nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), also known as nodular lymphocyte predominant B-cell lymphoma, partially overlaps with T-cell/histiocyte-rich large B-cell lymphoma (THRLCBL). NLPHL histology may vary in architecture and B-cell/T-cell composition of the tumour microenvironment. However, the immune cell phenotypes accompanying different histological patterns remain poorly characterised.

Methods

We applied a multiplexed immunofluorescence workflow to identify differential expansion/depletion of multiple microenvironmental immune cell phenotypes between cases of NLPHL showing different histological patterns (as described by Fan et al, 2003) and cases of THRLBCL.

Results

FOXP3-expressing T-regulatory cells were conspicuously depleted across all NLPHL cases. As histology progressed to variant Fan patterns C and E of NLPHL and to THRLBCL, there were progressive expansions of cytotoxic granzyme-B-expressing natural killer and CD8-positive T-cells, PD1-expressing CD8-positive T-cells, and CD163-positive macrophages including a PDL1-expressing subset. These occurred in parallel to depletion of NKG2A-expressing natural killer and CD8-positive T-cells.

Discussion

These findings provide new insights on the immunoregulatory mechanisms involved in NLPHL and THLRBCL pathogenesis, and are supportive of an increasingly proposed biological continuum between these two lymphomas. Additionally, the findings may help establish new biomarkers of high-risk disease, which could support a novel therapeutic program of immune checkpoint interruption targeting the PD1:PDL1 and/or NKG2A:HLA-E axes in the management of high-risk NLPHL and THRLBCL.

[Strategy of the French Society of Childhood Cancer (SFCE) for pediatric nodular lymphocyte predominant lymphoma]

Nodular Lymphocyte predominant Hodgkin lymphoma (NLPHL) are rare lymphomas in pediatric patients comprising less than 10 % of all Hodgkin lymphoma (HL). They are for the most part diagnosed at stage I or II and indolent with lymphadenopathy often preceding the diagnosis by many months/years. Survival is excellent. Historically, patients were treated according to classical HL protocols. Due to high toxicity and excellent prognosis, management of NLPHL shifted to de-escalation protocol with good results. No treatment beyond surgical resection was proposed for localized unique nodal disease completely resected. The closed European protocol (EuroNet PHL LP1) evaluated the efficacy of low intensity chemotherapy protocol based on CVP courses (cyclophosphamide vinblastine prednisone) for stage IA/IIA not fully resected. Final results are not yet available. Advanced stage NLPHL are rare and there is no clinical trial and no consensus treatment in children. The SFCE lymphoma committee recently established recommendations for staging and treatment of limited and advanced NLPHL in children based on current practices and published results. The goal was to allow homogeneous practice on a national scale. If incomplete resection for patients with stage I/IIA combination of low intensity chemotherapy (CVP) and rituximab is recommended. For intermediary and advanced stage intensification with AVD (adriamycine vinblastine dacarbazine) or CHOP courses (cyclophosphamide doxorubicine vincristine prednisone) combined with rituximab are advocated. In children, there is no indication for first-line local treatment with radiotherapy.

Nodular lymphocyte-predominant Hodgkin lymphoma: current management strategies and evolving approaches to individualize treatment

INTRODUCTION

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma entity accounting for roughly 5% of all Hodgkin lymphoma (HL) cases. In contrast to classical HL, the malignant cells in NLPHL are positive for CD20 but lack CD30. The disease usually has an indolent clinical course resulting in high long-term survival rates.

AREAS COVERED

In this review, treatment options for NLPHL are summarized and factors that may help to individualize treatment are discussed.

EXPERT OPINION

Stage IA NLPHL without clinical risk factors should be treated with limited-field radiotherapy alone. In all other stages, NLPHL patients have excellent outcomes after standard HL approaches. The question of whether the addition of an anti-CD20 antibody to standard HL chemotherapy protocols or the use of approaches typically applied in B-cell non-Hodgkin lymphoma improve treatment results is unanswered until now. Different management strategies ranging from low-intensity treatment to high-dose chemotherapy and autologous stem cell transplantation have demonstrated activity in relapsed NLPHL. Second-line treatment is thus chosen individually. The major aim of NLPHL research is to spare toxicity and reduce the risk for treatment-related adverse events in low-risk patients while treating higher-risk patients with appropriate intensity. To this end, novel tools to guide treatment are required.

[Classification of Hodgkin lymphoma and related entities : News and open questions]

Two new classifications were recently released: the 5th edition of the WHO classification of hematolymphoid tumors and the International Consensus Classification (ICC) drafted by the Clinical Advisory Committee. In the preparation of both classifications, the previously existing lymphoma categories were reevaluated according to recently obtained data on clinical, morphological, and molecular findings. In this review we summarize the current placements of classic and nodular lymphocyte predominant Hodgkin lymphoma and their relevant differential diagnoses.

Treatment approaches for nodular lymphocyte-predominant Hodgkin lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare variant of Hodgkin lymphoma characterized by a persistent risk of relapse but an excellent overall survival. Historically, it was treated similarly to classic Hodgkin lymphoma, but efforts have been made to deintensify treatment due to risk of late toxicity associated with intensive therapy. For patients with completely resected stage IA NLPHL, no further treatment may be considered, particularly for pediatric patients. For those with stage I-II NLPHL without risk factors such as B symptoms, sites>2, or variant pattern histology, lower intensity treatment with radiotherapy or chemotherapy alone may be sufficient. However, combined modality therapy is a standard treatment for favorable and unfavorable risk stage I-II NLPHL associated with excellent progression-free and overall survival rates. For patients with advanced stage NLPHL, the optimal chemotherapy is not defined, but R-CHOP appears to be an effective treatment. Efforts to study NLPHL through multicenter collaborative efforts are crucial to develop evidence based and individualized treatments for patients with NLPHL.

Characterizing the immune microenvironment for nodular lymphocyte-predominant Hodgkin lymphoma

The microenvironment of nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) and its relationship to presentation and outcomes has not been widely investigated. In a large cohort of patients with NLPHL, Hartmann and colleagues showed an association between microenvironmental factors and clinical presentation serving to inform future studies evaluating the prognostic impact of the immunoarchitectural patterns and cell types present. Commentary on: Hartmann et al. Tumor cell characteristics and microenvironment composition correspond to clinical presentation in newly diagnosed nodular lymphocyte predominant Hodgkin lymphoma. Br J Haematol 2022 (Online ahead of print). doi: 10.1111/bjh.18376.

Tumour cell characteristics and microenvironment composition correspond to clinical presentation in newly diagnosed nodular lymphocyte-predominant Hodgkin lymphoma

Different studies have characterized the microenvironment and its prognostic impact in classic Hodgkin lymphoma whereas such analyses are pending for nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL). We thus investigated characteristics of tumour cells and microenvironment in NLPHL and evaluated possible correlations with the clinical presentation. Lymph node samples from 152 NLPHL patients who had first-line treatment within the randomized German Hodgkin Study Group HD16-HD18 trials were available and analysed with regard to IgD status and nuclear size of the tumour cells as well as presence of PD1-positive follicular T helper cells and CD163-positive macrophages in the microenvironment. While large tumour cell nuclei and high numbers of PD1-positive follicular T helper cells in the microenvironment were more common in patients presenting with early/intermediate stages than in patients with advanced-stage disease (p < 0.0001, unpaired t-test; p = 0.0022, Mann-Whitney test), no differences between risk groups were observed in terms of the IgD status of the tumour cells and the content of CD163-positive macrophages in the microenvironment. PD1-positive follicular T helper cells were present in both cases with typical and variant growth patterns and rosetting around the tumour cells was observed in 96% of patients, indicating an important role of PD1-positive follicular T helper cells in NLPHL.

The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms

We herein present an overview of the upcoming 5^th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4^th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5^th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.

Management of children and adults with all stages of nodular lymphocyte predominant Hodgkin lymphoma - All StAGEs: A consensus-based position paper from the Hodgkin lymphoma subgroup of the UK National Cancer Research Institute

A consensus statement for the management for patients of all ages with all stages of nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) - All StAGEs - is proposed by representatives of the UK National Cancer Research Institute (NCRI) Hodgkin lymphoma study group and the Children's Cancer & Leukaemia Group. Based on current practices and published evidence, a consensus has been reached regarding diagnosis, staging and risk-ik7 stratified management which includes active surveillance, low- and standard-dose immunochemotherapy and radiotherapy.

An Update on the Pathology and Molecular Features of Hodgkin Lymphoma

Simple Summary

Hodgkin lymphomas (HLs) include two main types, classic HL (CHL) and nodular lymphocyte predominant HL (NLPHL). Recent molecular findings in HLs have contributed to dramatic changes in the treatment and identification of tumor characteristics. For example, PD-1/PD-L1 blockade and brentuximab vedotin, an anti-CD30 antibody bearing a cytotoxic compound, are now widely used in patients with CHL. Biological continuity between NLPHL and T-cell/histiocyte-rich large B-cell lymphoma has been highlighted. An era of novel therapeutics for HL has begun. The aim of this paper is to review the morphologic, immunophenotypic, and molecular features of CHL and NLPHL, which must be understood for the development of novel therapeutics.

Abstract

Hodgkin lymphomas (HLs) are lymphoid neoplasms derived from B cells and consist histologically of large neoplastic cells known as Hodgkin and Reed–Sternberg cells and abundant reactive bystander cells. HLs include two main types, classic HL (CHL) and nodular lymphocyte predominant HL (NLPHL). Recent molecular analyses have revealed that an immune evasion mechanism, particularly the PD-1/PD-L1 pathway, plays a key role in the development of CHL. Other highlighted key pathways in CHL are NF-κB and JAK/STAT. These advances have dramatically changed the treatment for CHL, particularly relapsed/refractory CHL. For example, PD-1 inhibitors are now widely used in relapsed/refractory CHL. Compared with CHL, NLPHL is more characterized by preserved B cell features. Overlapping morphological and molecular features between NLPHL and T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) have been reported, and biological continuity between these two entities has been highlighted. Some THRLBCLs are considered to represent progression from NLPHLs. With considerable new understanding becoming available from molecular studies in HLs, therapies and classification of HLs are continually evolving. This paper offers a summary of and update on the pathological and molecular features of HLs for a better understanding of the diseases.

Nodular lymphocyte predominant Hodgkin lymphoma: Experience of Polish Pediatric Leukemia/Lymphoma Study Group

Nodular Lymphocyte Predominant Hodgkin Lymphoma (NLPHL) is a rare clinical entity. To investigate NLPHL clinical course and treatment a survey was performed within Polish Pediatric Leukaemia/Lymphoma Study Group (PPLLSG) participating centers. A questionnaire was sent to all participating centers and analysis of clinical data was performed. From 2010 to 2019, 19 pediatric patients with confirmed NLPHL were registered in Poland. Median age of patients was 12.2 (5.5 - 17.8) years. NLPHL occurred mainly in males (n = 17). Most of the patients (n = 16) had early stage disease - Stage I (n = 6) and stage II (n = 10). Four of the six patients with stage I disease (I A, n = 5; I B, n = 1) underwent complete primary resection. One of these relapsed and was treated with CVP (cyclophosphamide, vinblastine, prednisone) chemotherapy. Two other patients who were not resected completely received CVP chemotherapy and no relapses were observed. Thirteen patients presented with unresectable disease. Of these, eight received three CVP chemotherapy cycles, and five were treated with other chemotherapy regimens. Three relapses were observed and these patients were further treated with chemotherapy and rituximab. One patient underwent autologous stem cell transplantation (auto-SCT). All patients remain alive. Five-year progression-free survival and overall survival for the entire group of patients was 81.6% and 100%, respectively. NLPHL treatment results are consistent with results noted in other countries. Early stage patients have very good outcomes with surgery and observation or low intensity chemotherapy, but this approach may be insufficient in advanced disease.

Pitfalls in the Diagnosis of Nodular Lymphocyte Predominant Hodgkin Lymphoma: Variant Patterns, Borderlines and Mimics

Simple Summary

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma containing infrequent tumor cells (LP cells) in a background of non-neoplastic cells. Some cases of NLPHL can recur or progress to a more aggressive lymphoma, such as diffuse large B-cell lymphoma. Awareness of the different appearances of NLPHL and its overlap with other lymphomas are important for the appropriate diagnosis, classification and research. This article discusses the conceptual framework and guidelines for the diagnosis of NLPHL, and how NLPHL can be best separated from its mimics. Emerging data in the field point to genetic changes in LP cells that are shaped by immune mechanisms. In addition, non-neoplastic cells in the background of LP cells also appear to play an important role. Further investigation is necessary to fully understand the biology of NLPHL and personalize cancer care for patients affected by this lymphoma.

Abstract

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) represents approximately 5% of Hodgkin lymphoma and typically affects children and young adults. Although the overall prognosis is favorable, variant growth patterns in NLPHL correlate with disease recurrence and progression to T-cell/histiocyte-rich large B-cell lymphoma or frank diffuse large B-cell lymphoma (DLBCL). The diagnostic boundary between NLPHL and DLBCL can be difficult to discern, especially in the presence of variant histologies. Both diagnoses are established using morphology and immunophenotype and share similarities, including the infrequent large tumor B-cells and the lymphocyte and histiocyte-rich microenvironment. NLPHL also shows overlap with other lymphomas, particularly, classic Hodgkin lymphoma and T-cell lymphomas. Similarly, there is overlap with non-neoplastic conditions, such as the progressive transformation of germinal centers. Given the significant clinical differences among these entities, it is imperative that NLPHL and its variants are carefully separated from other lymphomas and their mimics. In this article, the characteristic features of NLPHL and its diagnostic boundaries and pitfalls are discussed. The current understanding of genetic features and immune microenvironment will be addressed, such that a framework to better understand biological behavior and customize patient care is provided.

Lymphocyte predominant cells of nodular lymphocyte predominant Hodgkin lymphoma interact with rosetting T cells in an immunological synapse

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a subtype of Hodgkin lymphoma with a preserved B-cell phenotype and follicular T helper (T_FH ) cells rosetting around the tumor cells, the lymphocyte-predominant (LP) cells. As we recently described reactivity of the B-cell receptors of LP cells of some NLPHL cases with Moraxella spp. proteins, we hypothesized that LP cells could present peptides to rosetting T cells in a major histocompatibility complex class II (MHCII)-bound manner. Rosetting PD1⁺ T cells were present in the majority of NLPHL cases, both in typical (17/20) and variant patterns (16/19). In most cases, T-cell rosettes were CD69⁺ (typical NLPHL, 17/20; NLPHL variant, 14/19). Furthermore, both MHCII alpha and beta chains were expressed in the LP cells in 23/39 NLPHL. Proximity ligation assay and confocal laser imaging demonstrated interaction of the MHCII beta chain expressed by the LP cells and the T-cell receptor alpha chain expressed by rosetting T cells. We thus conclude that rosetting T cells in NLPHL express markers that are encountered after antigenic exposure, that MHCII is expressed by the LP cells, and that LP cells interact with rosetting T cells in an immunological synapse in a subset of cases. As they likely receive growth stimulatory signals in this way, blockade of this interaction, for example, by PD1-directed checkpoint inhibitors, could be a treatment option in a subset of cases in the future.

Lymphocyte predominant Hodgkin lymphoma, antigen-driven after all?

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) was suggested as an entity separate from other types of Hodgkin lymphoma 40 years ago and recognized in the WHO classification in 2001. Based on its relatively benign course with late distant relapses, relation with lymph node hyperplasia with progressively transformed germinal centers, presence of clonal immunoglobulin gene rearrangements with somatic hypermutations and ongoing mutations, and relation with a number of inherited defects affecting the immune system, it has been suspected that NLPHL might be antigen-driven. Recent evidence has shown that cases of IgD-positive NLPHL are associated with infection by Moraxella catarrhalis, a common bacterium in the upper respiratory tract and in lymph nodes. This review summarizes the evidence for NLPHL as a B-cell lymphoma involving follicular T-lymphocytes normally found in germinal centers, its molecular features and relation to inherited immune defects, and its relation and differential diagnosis from similar entities. Finally, it discusses the evidence that in many cases a watch and wait policy might be a viable initial management strategy. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Association of Combined Modality Therapy vs Chemotherapy Alone With Overall Survival in Early-Stage Pediatric Hodgkin Lymphoma

Importance

To date, there is no well-defined standard of care for early-stage pediatric Hodgkin lymphoma (HL), which may include chemotherapy alone or combined modality therapy (CMT) with chemotherapy followed by radiotherapy. Although the use of radiotherapy in pediatric HL is decreasing, this strategy remains controversial.

Objective

To examine the use of CMT in pediatric HL and its association with improved overall survival using data from a large cancer registry.

Design, Setting, and Participants

This observational cohort study used data from the National Cancer Database to evaluate clinical features and survival outcomes among 5657 pediatric patients (age, 0.1-21 years) who received a diagnosis of stage I or II HL in the United States from January 1, 2004, to December 31, 2015. Statistical analysis was conducted from May 1 to November 1, 2018.

Exposures

Patients received definitive treatment with chemotherapy or CMT, defined as chemotherapy followed by radiotherapy.

Main Outcomes and Measures

Kaplan-Meier survival curves were used to examine overall survival. The association between CMT use, covariables, and overall survival was assessed in multivariable Cox proportional hazards regression models. Use of radiotherapy was assessed over time.

Results

Among the 11 546 pediatric patients with HL in the National Cancer Database, 5657 patients (3004 females, 2596 males, and 57 missing information on sex; mean [SD] age, 17.1 [3.6] years) with stage I or II classic HL were analyzed. Of these patients, 2845 (50.3%) received CMT; use of CMT vs chemotherapy alone was associated with younger age (<16 years, 1102 of 2845 [38.7%] vs 856 of 2812 [30.4%]; P < .001), male sex (1369 of 2845 [48.1%] vs 1227 of 2812 [43.6%]; P < .001), stage II disease (2467 of 2845 [86.7%] vs 2376 of 2812 [84.5%]; P = .02), and private health insurance (2065 of 2845 [72.6%] vs 1949 of 2812 [69.3%]; P = .002). The 5-year overall survival was 94.5% (confidence limits, 93.8%, 95.8%) for patients who received chemotherapy alone and 97.3% (confidence limits, 96.4%, 97.9%) for those who received CMT, which remained significant in the intention-to-treat analysis and multivariate analysis (adjusted hazard ratio for CMT, 0.57; 95% CI, 0.42-0.78; P < .001). In the sensitivity analysis, the low-risk cohort (stage I-IIA) and adolescent and young adult patients had the greatest benefit from CMT (adjusted hazard ratio, 0.47; 95% CI, 0.40-0.56; P < .001). The use of CMT decreased by 24.8% from 2004 to 2015 (from 59.7% [271 of 454] to 34.9% [153 of 438]).

Conclusions and Relevance

In this study, pediatric patients with early-stage HL receiving CMT experienced improved overall survival 5 years after treatment. There is a nationwide decrease in the use of CMT, perhaps reflecting the bias of ongoing clinical trials designed to avoid consolidation radiotherapy. This study represents the largest data set to date examining the role of CMT in pediatric HL.

The time to relapse correlates with the histopathological growth pattern in nodular lymphocyte predominant Hodgkin lymphoma

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) can present with different histopathological growth patterns. The impact of these histopathological growth patterns on relapse characteristics is unknown. We therefore analyzed paired biopsies obtained at initial diagnosis and relapse from 33 NLPHL patients who had received first-line treatment within German Hodgkin Study Group (GHSG) trial protocols, and from a second cohort of 41 relapsed NLPHL patients who had been treated outside GHSG studies. Among the 33 GHSG patients, 21 patients presented with a typical growth pattern at initial diagnosis, whereas 12 patients had a variant histology. The histopathological growth patterns at initial diagnosis and at relapse were consistent in 67% of cases. A variant histology at initial diagnosis was associated with a shorter median time to lymphoma recurrence (2.8 vs 5.2 years; P = .0219). A similar tendency towards a shorter median time to lymphoma recurrence was observed for patients presenting with a variant histology at relapse, irrespective of the growth pattern at initial diagnosis. Results obtained from the 41 NLPHL patients who had been treated outside GHSG studies were comparable (median time to lymphoma recurrence for variant histology vs typical growth pattern at initial diagnosis: 1.5 vs 7.0 years). In conclusion, the histopathological growth pattern remains consistent at relapse in the majority of NLPHL cases, and has major impact on the time of relapse.

Multiple Cavitary Lung Lesions in an Adolescent: Case Report of a Rare Presentation of Nodular Lymphocyte Predominant Hodgkin Lymphoma

A 14-year-old male patient presented with a nonproductive cough, weight loss, fatigue, and malaise. A chest radiograph showed large bilateral cavitary lung lesions in both upper and lower lobes that failed to improve with antibiotics and anti-inflammatory medications. Infectious and rheumatologic work-ups were negative. Thoracoscopic lung biopsies were diagnostic for nodular lymphocyte predominant Hodgkin lymphoma (NLPHL). The patient received combination chemotherapy and immunotherapy based on current treatment standards with an excellent clinical response. NLPHL is a rare B-cell lymphoma that typically presents as peripheral lymph nodal disease, clinically distinct from classical Hodgkin lymphoma. The prognosis of NLPHL in children is favorable, although relapse rates are high. This case details several unique features of NLPHL and describes the presentation, diagnosis, and treatment of an adolescent male with a rare pulmonary and cervical NLPHL, the first such case described in a pediatric patient.

Unfavorable presentation but comparable outcome: Presentation and outcome of children with nodular lymphocyte predominant Hodgkin lymphoma from India

BACKGROUND

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is an uncommon subtype of Hodgkin lymphoma (HL) with few published studies in children, entirely from North America and Europe. We analyzed clinical features and treatment outcome of pediatric NLPHL.

PROCEDURE

Children less than 18 years of age diagnosed after histopathology review to have NLPHL between June 1998 and August 2016 were retrospectively analyzed. Descriptive details of clinical presentation and treatment were collected, and outcomes analyzed using Kaplan-Meier survival analysis.

RESULTS

Of the 42 patients with a confirmed diagnosis of NLPHL during this period, there was complete information on 35. Median age was 11 years (range 6-16 years), male:female ratio was 4.8:1, there were 15, 11, 6, and 3 patients with Stage I, Stage II, Stage III, and Stage IV disease, respectively. Six patients had B symptoms, 10 had bulky disease, and 3 had bone marrow as well as extranodal involvement. Histology was typical NLPHL in 23 and variant in 12. Twenty-nine received chemotherapy, 10 with additional radiation, 3 patients with early stage disease received only radiotherapy and three others underwent complete node resection alone. Median follow-up was 55 months (range 7-165 months), 5 year event-free survival (EFS) was 83.3%, and overall survival 97.1%. Variant NLPHL histology was associated with higher incidence of unfavorable presentation and lower EFS.

CONCLUSIONS

NLPHL in India has an excellent outcome, despite a higher incidence of unfavorable presentations such as advanced stage disease, B symptoms, and bulky disease. Variant histology is an adverse prognostic factor.

Variant histology, IgD and CD30 expression in low-risk pediatric nodular lymphocyte predominant Hodgkin lymphoma: A report from the Children's Oncology Group

BACKGROUND

Histologic prognostic factors have been described for nodular lymphocyte predominant Hodgkin lymphoma (NLPHL). This study examines histologic and immunophenotypic variants in a clinical trial for pediatric NLPHL.

PROCEDURE

One hundred sixty-eight cases of localized NLPHL were examined for histologic variants, CD30 and immunoglobulin D (IgD) expression, and outcome. Histologic types were scored categorically as 0 = 0, 1 ≤ 25%, and 2 > 25% of the sample.

RESULTS

Fifty-eight (35.1%) cases showed only typical nodular with or without serpiginous histology (types A and B). The remainder showed mixtures of histologies. The numbers of patients with score 2 are 85 (50.6%) type A, 21 (12.5%) type B, 46 (27.4%) with extranodular large B cells (type C), 3 with T-cell-rich nodular pattern (type D), 55 (32.7%) with diffuse T-cell-rich (type E) pattern, and 2 (1.2%) with diffuse B-cell pattern (type F). Higher level of types C (P = 0.048) and D (P = 0.033) resulted in lower event-free survival (EFS). Cytoplasmic IgD was found in 65 of 130 tested (50%), did not significantly associate with EFS but positively correlated with types C and E histology (P < 0.0001) and negatively correlated with types A (P = 0.0003) and B (P = 0.006). Seventeen (10%) expressed CD30, with no adverse effect.

CONCLUSIONS

Variant histology is common in pediatric NLPHL, especially types C and E, which are associated with IgD expression. Type C variant histology and possibly type D are associated with decreased EFS, but neither IgD nor CD30 are adverse features. Variant histology may warrant increased surveillance, but did not affect overall survival.

Advanced stage nodular lymphocyte predominant Hodgkin lymphoma in children and adolescents: clinical characteristics and treatment outcome - a report from the SFCE & CCLG groups

Advanced stage nodular lymphocyte predominant Hodgkin lymphoma (nLPHL) is extremely rare in children and as a consequence, optimal treatment for this group of patients has not been established. Here we retrospectively evaluated the treatments and treatment outcomes of 41 of our patients from the UK and France with advanced stage nLPHL. Most patients received chemotherapy, some with the addition of the anti CD20 antibody rituximab or radiotherapy. Chemotherapy regimens were diverse and followed either classical Hodgkin lymphoma or B non-Hodgkin lymphoma protocols. All 41 patients achieved a complete remission with first line treatment and 40 patients are alive and well in remission. Eight patients subsequently relapsed and 1 patient died of secondary cancer (9 progression-free survival events). The median time to progression for those who progressed was 21 months (5·9-73·8). The median time since last diagnosis is 87·3 months (8·44-179·20). Thirty-six (90%), 30 (75%) and 27 (68%) patients have been in remission for more than 12, 24 and 36 months, respectively. Overall, the use of rituximab combined with multi-agent chemotherapy as first line treatment seems to be a reasonable therapeutic option.

[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.

Minimal Treatment of Low-Risk, Pediatric Lymphocyte-Predominant Hodgkin Lymphoma: A Report From the Children's Oncology Group

PURPOSE

Children's Oncology Group study AHOD03P1 was designed to determine whether excellent outcomes can be maintained for patients with low-risk, pediatric lymphocyte-predominant Hodgkin lymphoma (LPHL) with a strategy of resection alone or minimal chemotherapy.

PATIENTS AND METHODS

Patients with stage IA LPHL in a single node that was completely resected were observed without further therapy; recurrences were treated with three cycles of doxorubicin/vincristine/prednisone/cyclophosphamide (AV-PC). Patients with unresected stage IA or stage IIA LPHL were treated with three cycles of AV-PC. Patients with less than a complete response (CR) to AV-PC received 21-Gy involved-field radiation therapy (IFRT).

RESULTS

A total of 183 eligible patients were enrolled; 178 were evaluable. Of these, 52 patients underwent complete resection of a single node. There were 13 relapses at a median of 11.5 months; 5-year event-free survival (EFS) was 77% (range, 62% to 87%). A total of 135 patients received AV-PC; 126 were treated at diagnosis and nine at relapse after surgery alone. Eleven patients receiving AV-PC had less than CR and received IFRT. Fourteen first events occurred among 135 patients (12 relapses and two second malignancies). Two relapses occurred in patients who had received IFRT. Five-year EFS was 88.8% (95% CI, 81.8% to 93.2%). Five-year EFS for the entire cohort was 85.5% (95% CI, 79.2% to 90.1%); overall survival was 100%.

CONCLUSION

Some 75% of highly selected pediatric patients with LPHL may be spared chemotherapy after surgical resection alone. Pediatric LPHL has excellent EFS with chemotherapy that is less intensive than standard regimens; > 90% of patients can avoid radiation therapy. The salvage rate for the few relapses is high, with 100% survival overall.

Relapsed or poorly responsive nodular lymphocyte predominant Hodgkin lymphoma in children and adolescents - a report from the United Kingdom's Children's Cancer and Leukaemia Study Group

There is a paucity of data on the treatment outcome in children with relapsed or poorly responsive nodular lymphocyte predominant Hodgkin lymphoma (nLPHL). This retrospective report evaluates the treatment outcome in a national cohort of children with relapsed or poorly responsive nLPHL. A total of 37 patients, 22 with relapsed and 15 with poorly responding disease, are the subjects of this report. Of the 22 patients with relapsed nLPHL, 11 had relapsed after primary excision biopsy, 10 after chemotherapy and 1 after chemotherapy and involved field radiotherapy. The majority had localized disease at relapse. The median time to relapse was 8 months after chemotherapy and 11 months after excision biopsy. Seven of the 15 patients with poorly responding nLPHL had variant histology. Three patients with initial poor response did not receive any further treatment and have had no disease progression. Transformation to diffuse large B cell lymphoma, in addition to evolution from typical to variant nLPHL occurred in one patient each. Thirty-four patients have been successfully re-treated with second chemotherapy or radiotherapy. Multiple relapses were uncommon but treatable. Relapse or poorly responsive nLPHL is fully salvageable with either additional chemotherapy and or radiotherapy.