Splenic marginal zone lymphoma
ICD-10 C88.4 · ICD-11 2A82.Y
First-Line Treatment of Splenic Marginal Zone Lymphoma
Splenic marginal zone lymphoma (SMZL) is an indolent B-cell lymphoma with characteristic involvement of the spleen and peripheral blood. At first presentation, treatment is directed at achieving a deep, measurable remission — with specific thresholds for organ size, blood counts, and molecular disease burden that define a complete response.
Treatment Approach
The preferred initial strategy for SMZL involves targeted monoclonal antibody therapy. A maintenance phase may follow the induction course to prolong remission. The full sequencing, criteria for initiating maintenance, and decision points are defined in the complete protocol.
Complete Response Criteria
Success is defined by achieving all of the following:
- Resolution of organomegaly — spleen longitudinal diameter <13 cm
- Haemoglobin >12 g/dl
- Platelets >100 ×10⁹/l
- Neutrophils >1.5 ×10⁹/l
- No circulating clonal B cells on flow cytometry
- No bone marrow infiltration on immunohistochemistry
References
DOI: 10.1016/j.annonc.2019.10.010
- Rituximab therapy alone (375 mg/m² 4- to 8-weekly doses) can produce a rapid response, with a high overall response rate (>80%) and CRR (>40%) with minimal toxicity.
- Maintenance with rituximab (every 2 months for 1-2 years) may improve PFS, but no OS advantage has been shown to date and maintenance may not be superior to retreatment on demand.
- Rituximab alone is the preferred initial therapy in patients with SMZL [III, A]
- Achievement of CR is defined by normal spleen size, normal blood counts, negative flow cytometry on blood and negative IHC on bone marrow biopsy.