Synopsis
Classify indolent lymphoma accurately, distinguish observation from treatment need, select local or systemic therapy by subtype and recognise transformation, paraprotein and treatment complications early.
- Indolent NHL includes follicular and nodal, splenic and extranodal marginal-zone lymphomas; lymphoplasmacytic lymphoma and some mantle-cell presentations need their own biology-led pathways.
- Reference-standard diagnosis is excision biopsy or adequate cores with architecture, flow, immunohistochemistry and genetics; do not label subtype from blood or PET alone.
- Advanced stage without symptoms is not a treatment indication: active monitoring is first-line for low-burden asymptomatic follicular lymphoma.
- Start therapy for threatened organ function, symptomatic bulky or progressive disease, marrow failure, significant B symptoms, splenic symptoms or disease-mediated cytopenia.
- Localised stage I–II follicular lymphoma can be treated with involved-site radiotherapy, commonly 24 Gy; selected observation or systemic treatment follows anatomy and patient priorities.
- Advanced symptomatic follicular disease uses anti-CD20-based immunochemotherapy selected from fitness, pace and toxicity, followed by maintenance in eligible responders under current commissioning.
- Gastric MALT lymphoma requires H. pylori testing and eradication as first-line when infected, with endoscopic and histological response follow-up.
- Rapid discordant growth, new pain, high LDH or severe B symptoms requires PET-CT to choose a biopsy site for transformation; PET cannot replace histology.
- Do not use routine surveillance PET after remission; follow symptoms, examination and blood tests and image a new clinical concern.
- Screen hepatitis B before anti-CD20 therapy and use antiviral prophylaxis when indicated; avoid live vaccines during meaningful B-cell depletion.
Key red flags
One node enlarging rapidly, new severe pain, extranodal mass, disproportionate LDH rise or new B symptoms suggests transformation and requires urgent PET-directed biopsy.
Cytopenic bleeding, recurrent infection, haemolysis, massive symptomatic spleen or organ compression can create a treatment indication even without rapid growth.
Headache, visual change, mucosal bleeding or neurological symptoms with an IgM paraprotein suggests hyperviscosity and requires urgent viscosity and plasma-exchange assessment.
Fever during bendamustine, anti-CD20 or maintenance treatment is infection until assessed; lymphocyte depletion can produce prolonged viral and opportunistic risk.
One rapidly enlarging painful site, major LDH rise or new severe B symptoms requires urgent targeted biopsy.
Investigation priorities
Preserve architecture and establish exact indolent subtype and grade.
Management branches
Biopsy suggests a small B-cell or follicular lymphoma.
- Complete specialist pathology with grade, phenotype and defining genetics and resolve mantle-cell, CLL and lymphoplasmacytic alternatives.
- Stage with subtype-appropriate imaging and assess symptoms, bulk, organ threat, marrow, paraprotein and infection.
- Choose observation, local radiotherapy, cause-directed therapy or systemic treatment from subtype and treatment indication.