[Lymphomas in children and adolescents]

BACKGROUND

Lymphomas in children and adolescents differ from adulthood in relative frequency and variety of entities. In addition, young patients are cared for according to the specific standards of pediatric lymphoma study groups.

OBJECTIVE

To present lymphomas of diagnostic and clinical relevance in the pediatric and adolescent group.

MATERIAL AND METHODS

Selective literature research ( http://www.ncbi.nlm.nih.gov ) was combined with clinico-pathological experience of the authors.

RESULTS

Children and adolescents are much more likely to suffer from aggressive and precursor cell lymphoma than is the case in adulthood. Unlike adult patients, Burkitt lymphomas and diffuse large B‑cell lymphomas are not treated fundamentally differently. Entities that have been described relatively recently and are particularly common in young patients are high-grade B‑cell lymphoma with 11q aberrations and large-cell B‑cell lymphoma with IRF4 translocations.

CONCLUSION

Lymphoma diagnosis in children and adolescents is characterized by the particular spectrum of diseases that occur at this age. Special knowledge about the clinical relevance of the diagnoses in childhood is helpful in order to enable rapid clinical decision making.

[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.

[Classification of aggressive B-cell lymphomas : News and open questions]

The 5th edition of the WHO classification (WHO-HAEM5) and the International Consensus Classification (ICC) show a broad consensus in the categorization of aggressive, large B‑cell lymphomas with expected minor impact only on the daily diagnostic routine. The changes compared to the 2017 revised WHO-HAEM4R are moderate and include updated names of entities, sharpened diagnostic criteria, and upgrades from provisional to definite entities. The definition of the most common aggressive B‑cell lymphoma, diffuse large B‑cell lymphoma (DLBCL), not otherwise specified (NOS), remains unchanged, and both classifications strongly encourage subtyping into germinal center B‑like (GCB) or the activated B‑like (ABC or non-GCB) DLBCL. DLBCL, NOS, should be separated from other large B‑cell lymphomas including large B‑cell lymphoma with IRF4 rearrangement (upgraded to a definite entity in both classifications) and large-cell/high-grade B‑cell lymphomas with 11q aberration. Aggressive B‑cell lymphomas with MYC and BCL2 rearrangements form a molecularly distinct group and are listed as definite entities in both classifications. This is in contrast to the more heterogeneous group of aggressive B‑cell lymphomas with MYC and BCL6 rearrangements that are recognized as a provisional entity in the ICC, while they fall into the DLBCL, NOS, or the HGBL, NOS, groups in the WHO-HAEM5.

[Lymphomas and other hematological neoplasms in the testicles]

BACKGROUND

The testis may be infiltrated by hematological neoplasias. However, only few entities present as primary testicular diseases.

OBJECTIVES

To present hematological neoplasias in the testis, especially primary testicular hematological diseases.

MATERIALS AND METHODS

Selective literature research ( http://www.ncbi.nlm.nih.gov ) was combined with the clinico-pathological experience of the authors.

RESULTS

We present the experience of the lymph node registry Kiel with hematological neoplasias of the testis and develop a staining recommendation. According to our data, the testis is mainly involved by diffuse large B‑cell lymphomas (~70% of cases) followed by precursor cell neoplasias (~20%). Most precursor cell neoplasias are disseminated diseases involving the testis. Primary testicular lymphomas are nearly exclusively diffuse large B‑cell lymphomas that show specific clinical, pathological, and molecular features discriminating them from nodal/disseminated lymphomas. Primary testicular follicular lymphomas, which have been described in the literature, seem to be extremely rare.

CONCLUSION

Primary testicular lymphomas are predominantly diffuse large B‑cell lymphomas. The diagnosis is possible with few immunohistochemical stainings. However, histology cannot replace clinical staging to discriminate primary testicular lymphoma from secondary infiltration by a nodal/disseminated disease.

Long-term remissions in patients with early relapse of diffuse large B-cell lymphoma following high-dose chemotherapy, autologous stem cell transplantation, and radiotherapy of residual disease

PURPOSE

The prognosis of an early relapse of diffuse large B-cell lymphoma (DLBCL) appears to be poor following autologous stem cell transplantation (ASCT). The aim of this study is to contribute data to the open question on whether additional radiotherapy can improve the outcome.

PATIENTS AND METHODS

Forty-eight patients with an early relapse (median 4 months after the end of initial immunochemotherapy, range 1-11) of DLBCL have been treated in our institution with high-dose therapy (usually the BEAM protocol) and ASCT since 2008 (median age 61 years, range 28-73). Twenty-three patients received ASCT in a second treatment line, 25 in a third line (19 refractory to second-line salvage therapy, 5 after second relapse). Fifteen of these 48 patients received radiotherapy (36-50 Gy, median 40) of residual masses after ASCT.

RESULTS

Three-year overall survival (OS) and progression-free survival (PFS) after second-line ASCT were 61 and 57%, after third-line ASCT 47 and 44%, respectively, without significant differences. A prognostic factor was the International Prognostic Index (IPI) at the start of salvage therapy. Three-year OS and PFS in low-risk patients were 69 and 69%, in low-intermediate-risk 63 and 53%, and in high-intermediate-risk 23 and 23%, respectively (p = 0.033). Twenty-three patients achieved a sustained complete remission (13-146 months, median 62).

CONCLUSION

Sustained long-term remissions can be achieved in patients with early relapse of DLBCL following ASCT in a second or third treatment line, particularly in patients with low- and low-intermediate-risk IPI, following radiotherapy of residual disease after ASCT. Further investigations are required to clarify which patients need an alternative therapy (potentially CAR T‑cells or allogeneic transplantation).

[Genetic evolution of in situ follicular neoplasia to t(14;18)-positive aggressive B-cell lymphoma]

BACKGROUND

In situ follicular neoplasia (ISFN) is a t(14;18)(q32;q21)⁺ precursor lesion of follicular lymphoma (FL), which in turn can transform into diffuse large B‑cell lymphoma (DLBCL). For DLBCL that arise de novo, no precursor lesion is known. Given the high frequency of the t(14;18) translocation in de novo DLBCL as well, we investigated whether they can also arise from ISFN without FL as an intermediate step.

OBJECTIVES

To investigate the clonal evolution of ISFN to DLBCL - transformed from FL and de novo.

MATERIALS AND METHODS

Identification of ISFN lesions in patients with DLBCL was performed by BCL2 staining of reactive lymphoid tissues. ISFN and DLBCL were subsequently analyzed by fluorescence in situ hybridization, clonality analyses, sequencing of the t(14;18) breakpoint, and targeted next-generation sequencing.

RESULTS

10 cases with paired ISFN and DLBCL samples were identified, 6 of which were de novo DLBCL and 4 transformed from FL. 3 DLBCL carried MYC-rearrangements in addition to the t(14;18) and were classified as high-grade B‑cell lymphoma (HGBL). The clonal relationship of ISFN and DLBCL/HGBL was confirmed for all cases. CREBBP, KMT2D, EZH2, TNFRSF14, and BCL2 were the genes most frequently mutated, with the distribution of private and shared mutations pointing to 2 different scenarios of clonal evolution. In most cases, DLBCL/HGBL, ISFN, and, if also present, FL had evolved divergently from a common progenitor, whereas linear evolution was less frequent.

CONCLUSION

We show for the first time that t(14;18)⁺ DLBCL/HGBL can arise directly from ISFN without FL as an intermediate step and that during this progression, divergent evolution is common.

Clinicopathological and prognostic features of hepatitis B virus-associated diffuse large B-cell lymphoma: a single-center retrospective study in China

Background

While the epidemiologic association between hepatitis B virus (HBV) infection and diffuse large B-cell lymphoma (DLBCL) is established, little is known about the pathological characteristics and outcome of DLBCL arising in patients with HBV infection.

Methods

We retrospectively studied a cohort of 420 patients with DLBCL for the incidence of HBV infection, and the clinicopathologic features and prognostic factors in HBsAg-positive DLBCL patients in China, a hepatitis B endemic area.

Results

In our study, 127 (30.2%) patients were HBsAg-positive. HBsAg-positive DLBCL displayed a younger median onset age (50 vs. 54 years, P = 0.002), more frequent involvement of the spleen (19.7% vs. 6.1%, P < 0.001), less frequent involvement of the small and large intestine (2.3% vs. 11.2%, P = 0.003), more advanced disease (stage III/IV: 56.7% vs. 45.1%, P = 0.028), and lower expression rate of MYC (49.1% vs. 66.7%, P = 0.026). The median follow-up time was 61.9 months. Univariate analysis showed that there was no significant difference in overall survival (OS) between HBsAg-negative and -positive DLBCL (P = 0.577). In the HBsAg-positive DLBCL subgroup, age older than 60 years, advanced disease, elevated lactate dehydrogenase (LDH), spleen involvement, B symptoms (fever, night sweats, weight loss), and double expressers of MYC and BCL2 had a significantly worse outcome, and patients treated with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) had a better prognosis. Multivariate analysis further confirmed that spleen involvement and rituximab use were independent prognostic factors in HBsAg-positive DLBCL patients.

Conclusions

Our study indicates that HBsAg-positive DLBCL has unique clinicopathological features and independent prognostic factors. Moreover, under antiviral prophylaxis, the survival of DLBCL patients with HBV infections was comparable to that of HBV-negative patients, and the use of rituximab significantly improved OS in HBsAg-positive DLBCL patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13027-021-00396-x.

[CAR T-cell therapy for malignant B-cell lymphoma : A new treatment paradigm]

Following the first demonstration of efficacy of anti-CD19-directed chimeric antigen receptor (CAR) T cells in a patient with relapsed chronic lymphocytic leukemia (CLL) in 2011, pivotal studies for this innovative therapy were initially conducted in multiple relapsed or refractory (r/r) childhood and young adult acute B‑cell leukemia and in aggressive adult B‑cell lymphoma. The studies demonstrated efficacy even in chemotherapy-refractory disease, resulting in the first approval of autologous and genetically engineered T cells for the treatment of r/r B‑cell acute lymphoblastic leukemia (B-ALL) in the US for the product tisagenlecleucel (Kymriah®, Novartis) back in 2018. Approval for the treatment of r/r aggressive B‑cell lymphoma followed shortly thereafter for tisagenlecleucel and axicabtagene ciloleucel (Yescarta, Kite/Gilead). This review focuses on the treatment of aggressive B‑cell lymphoma and other CD19 positive B‑cell lymphomas by summarizing the study results of clinically tested CAR T cells, discussing possible resistance mechanisms, and providing an outlook on ongoing studies with new target antigens for the treatment of B‑cell lymphomas.

[Aggressive B‑cell lymphomas : Recommendations from the German Panel of Reference Pathologists in the Competence Network on Malignant Lymphomas on diagnostic procedures according to the current WHO classification, update 2017]

The update of the 4th edition of the WHO classification for hematopoietic neoplasms introduces changes in the field of mature aggressive B‑cell lymphomas that are relevant to diagnostic pathologists. In daily practice, the question arises of which analysis should be performed when diagnosing the most common lymphoma entity, diffuse large B‑cell lymphoma. We discuss the importance of the cell of origin, the analysis of MYC translocations, and the delineation of the new WHO entities of high-grade B‑cell lymphomas.