Splenic Lymphoma: A Series of Seven Cases

Abstract

Splenic Lymphoma (SL) is a lymphoproliferative disorder characterised by involvement of the spleen, with or without bone marrow involvement. However, advancements in imaging modalities have led to more frequent diagnosis of isolated splenic lesions. There is always a dilemma in diagnosis as to whether the pathology truly originates from the spleen or if it is part of systemic involvement in Non-Hodgkin Lymphoma (NHL). Clinical manifestations vary widely, and treatment outcomes for SL depend on accurate diagnosis. However, prognosis still remains poor in these cases compared to systemic NHL. The present case series provide a comprehensive overview of patients diagnosed with SL, focusing on their clinicopathological characteristics, therapeutic details, prognosis and outcomes. Previously isolated case reports have been published, and there is still a lack of consensus on the management of this entity. The present case series included seven cases over a two-year period, from January 2022 to December 2023. In the current case series, authors have highlighted the heterogeneity and variability in the presentation of SL and how the clinical behaviour ranges from indolent to highly aggressive. Nevertheless, the presenting clinical, laboratory and pathological features of these diseases often display significant overlaps and pose confusion in arriving at an exact diagnosis. The authors emphasise how flow cytometry helps facilitate the diagnosis and systemic therapy is the modality of choice for treatment decided based on the histology type; however, outcomes still remain dismal, highlighting the unmet need to improve accurate diagnosis and explore newer treatment options. The novelty in this series lies in the detailed analysis and comparison of different subtypes of SL, a rare group of lymphomas primarily originating in the spleen. The present case series discusses the latest World Health Organisation (WHO) classification, which redefines the Hairy Cell Leukaemia (HCL) variant as Splenic B-cell Leukaemia/Lymphoma with Prominent Nucleoli (SBLPN). Detailed molecular and genetic characteristics of various SLs are highlighted, such as the presence of the v-raf murine sarcoma viral oncogene homolog B1 (BRAF) p.V600E mutation in HCL, Mitogen-activated Protein Kinase 1 (MAP2K1) and Immunoglobulin Heavy Variable 4-34 (IGHV4-34) mutations in the HCL-variant, and 7q distortion in Splenic Marginal Zone Lymphoma (SMZL). Emphasis is placed on the individualised treatment approach based on specific patient profiles, genetic markers and disease characteristics. The study underscores the need for further research and clinical trials to validate emerging therapies, such as the use of Rituximab plus Doxorubicin, Bleomycin, Vinblastine and Dacarbazine (R-ABVD) in Hodgkin lymphoma and combinations of novel agents in aggressive SLs like HCL-variant and CD20-negative B-cell NHL.

Keywords

• hairy cell leukaemia
• hepato-splenic lymphoma
• splenomegaly
• splenic b-cell lymphoma/leukaemia with prominent nucleoli