# Splenic marginal zone lymphoma

Source: https://onco.cc/cancers/splenic-marginal-zone-lymphoma/  
OnCo record `splenic-marginal-zone-lymphoma` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Splenic marginal zone lymphoma is a slow-growing lymphoma that grows in the spleen and bone marrow, causing a very large spleen and a raised lymphocyte count but rarely swollen lymph nodes. Many people need no treatment for years; when they do, rituximab has largely replaced removal of the spleen, and hepatitis C should be treated first where it is present.

## Summary

WHO-HAEM5 keeps splenic marginal zone lymphoma as the splenic member of the marginal zone lymphoma family, defined by massive splenomegaly, moderate lymphocytosis with or without villous lymphocytes, marrow involvement, rare peripheral lymphadenopathy and an indolent course; with no randomised trials there is no formal standard of care, and splenectomy, done for many years, is no longer encouraged first-line because rituximab is as effective with less toxicity (Alaggio 2022; Rev Bras Hematol Hemoter 2017). Its genome carries recurrent NOTCH2, KLF2 and TP53 mutations, with TNFAIP3, KMT2D and TRAF3 also recurrent across 475 cases, though exome studies agree poorly with one another (Scientific Reports 2019). An association with hepatitis C virus is recognised in the ESMO guideline, which recommends antiviral therapy as first treatment in infected patients (Zucca 2020).

How it differs from its parent: it is diagnosed from blood, marrow and spleen rather than a tissue biopsy of an organ or node; it carries the NOTCH2 and KLF2 lesions the other marginal zone lymphomas mostly lack; and its differential diagnosis includes hairy cell leukaemia and the new WHO-HAEM5 category of splenic B-cell lymphoma/leukaemia with prominent nucleoli.

How common: no registry share in the sources read; rare.

Treatment: watch and wait while asymptomatic; antiviral therapy for hepatitis C-associated disease; rituximab alone or with chemotherapy for symptomatic disease; splenectomy for selected patients; BTK inhibitors and lenalidomide-rituximab as on the parent page (Zucca 2020; Rev Bras Hematol Hemoter 2017).

## Fields

- Kind: Cancer
- Last checked: 2026-09-24
- Also known as: SMZL; Splenic lymphoma with villous lymphocytes; Splenic marginal zone B-cell lymphoma
- Tags: subtype-page; wave4; haematologic; rare
- Group: haematologic
- Burden: Rare; the systematic review of its mutations gathered 475 sequenced cases from fourteen studies (Scientific Reports 2019). The ESMO guideline treats it as the least common of the three marginal zone lymphomas; no registry share is in the sources read.
- Subtypes: Splenic marginal zone lymphoma with villous lymphocytes; Hepatitis C-associated splenic marginal zone lymphoma; Splenic marginal zone lymphoma with NOTCH2 or KLF2 mutation; Transformed splenic marginal zone lymphoma (diffuse large B-cell)
- Biomarkers: Villous lymphocytes and marrow intrasinusoidal infiltration; NOTCH2, KLF2 and TP53 mutations; Hepatitis C serology; Immunophenotype: CD20 positive, CD5, CD10, CD103 and annexin A1 negative

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/splenic-marginal-zone-lymphoma/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/splenic-marginal-zone-lymphoma/#overview
- What it is (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/splenic-marginal-zone-lymphoma/#what-it-is [4 subtypes]
- Finding it (on the hub): How it shows itself, how it is confirmed, what screening exists, and the biomarkers clinicians test for. https://onco.cc/cancers/splenic-marginal-zone-lymphoma/#finding-it [4 biomarkers]
- Treating it (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/splenic-marginal-zone-lymphoma/#treating-it [2 settings, 1 decision with options]
- Evidence (on the hub): Trials recruiting now, the landmark trials, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/splenic-marginal-zone-lymphoma/#evidence [1 trial]
- The science (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/splenic-marginal-zone-lymphoma/#science [4 targets]
- Where you are (own page): Cases by country, the UK and NHS pathway and other country lenses, and the expert centres with trials on record. https://onco.cc/cancers/splenic-marginal-zone-lymphoma/where-you-are/
- Living with it (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/splenic-marginal-zone-lymphoma/#living-with-it [10 questions, 6 red cards]
- What is coming (own page): Everything in development, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/splenic-marginal-zone-lymphoma/coming/ [4 medicines]
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/splenic-marginal-zone-lymphoma/data/ [22 connected records]

## Standard of care

- Asymptomatic: Watch and wait; antiviral therapy first if hepatitis C is present. ([Marginal zone lymphoma](https://onco.cc/cancers/marginal-zone-lymphoma/))
- Symptomatic: Rituximab alone or with chemotherapy; splenectomy for selected patients; BTK inhibitors or lenalidomide-rituximab later. ([Rituximab](https://onco.cc/drugs/rituximab/), [Bendamustine](https://onco.cc/drugs/bendamustine/), [Zanubrutinib](https://onco.cc/drugs/zanubrutinib/), [Lenalidomide](https://onco.cc/drugs/lenalidomide/), [AUGMENT](https://onco.cc/trials/augment/))

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Splenic_marginal_zone_lymphoma
- NCI PDQ: adult non-Hodgkin lymphoma treatment: https://www.cancer.gov/types/lymphoma/patient/adult-nhl-treatment-pdq
- Alaggio 2022, Leukemia: the 5th edition WHO classification of haematolymphoid tumours, lymphoid neoplasms: https://doi.org/10.1038/s41375-022-01620-2
- Zucca 2020, Annals of Oncology: marginal zone lymphomas, ESMO clinical practice guidelines: https://doi.org/10.1016/j.annonc.2019.10.010
- Rev Bras Hematol Hemoter 2017: splenic marginal zone lymphoma, review of diagnostic and therapeutic challenges: https://doi.org/10.1016/j.bjhh.2016.09.014
- Scientific Reports 2019: systematic review of somatic mutations in splenic marginal zone lymphoma, 475 cases: https://doi.org/10.1038/s41598-019-46906-1

## Connected records

- cancers: [Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)](https://onco.cc/cancers/malt-lymphoma/), [Hairy cell leukaemia](https://onco.cc/cancers/hairy-cell-leukemia/), [Marginal zone lymphoma](https://onco.cc/cancers/marginal-zone-lymphoma/), [Nodal marginal zone lymphoma](https://onco.cc/cancers/nodal-marginal-zone-lymphoma/), [Splenic B-cell lymphoma/leukaemia with prominent nucleoli (formerly B-cell prolymphocytic leukaemia and hairy cell leukaemia variant)](https://onco.cc/cancers/splenic-b-cell-lymphoma-leukaemia-prominent-nucleoli/)
- drugs: [Bendamustine](https://onco.cc/drugs/bendamustine/), [Lenalidomide](https://onco.cc/drugs/lenalidomide/), [Rituximab](https://onco.cc/drugs/rituximab/), [Zanubrutinib](https://onco.cc/drugs/zanubrutinib/)
- trials: [AUGMENT](https://onco.cc/trials/augment/)

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JSON: https://onco.cc/api/v1/entities/splenic-marginal-zone-lymphoma.json