Marginal zone lymphoma (MZL) is described in the packet as a usually indolent mature B-cell lymphoma arising from the marginal zone of lymphoid tissues and characterized by small to medium sized atypical lymphocytes. The definition groups it into three entities by anatomic site: extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue, nodal marginal zone B-cell lymphoma, and splenic marginal zone B-cell lymphoma. Orphanet-derived prevalence is categorized as uncommon, approximately 1 to 9 per 100,000.

No structured phenotype list is certified in this packet, so symptom frequencies are not available here. The definition describes where each entity occurs. The extranodal form affects sites such as the stomach, lung, skin, and ocular adnexa. The nodal form affects lymph nodes without evidence of extranodal disease. The splenic form affects the spleen and splenic hilar lymph nodes, bone marrow, and often the peripheral blood.

The packet lists no associated genes and no inheritance pattern, and it certifies no causal mechanism. The genetic and other causes of marginal zone lymphoma are therefore not described here.

No diagnostic methods or criteria are certified in this packet. The definition describes classification into the three anatomic entities and the presence of small to medium sized atypical lymphocytes.

Treatment content is not certified in this packet. It lists no FDA-approved treatments and no foundational therapies for this condition, so the absence of listed treatments reflects the packet and not the state of clinical practice.

The packet definition describes marginal zone lymphoma as usually indolent. Natural history, survival, and outcome data are not certified in this packet.

ClinicalTrials.gov records in the packet include a phase 3 trial sponsored by BeOne Medicines whose title compares zanubrutinib plus anti-CD20 with lenalidomide plus rituximab in relapsed or refractory follicular or marginal zone lymphoma (NCT05100862, active not recruiting). Other records include a phase 2 trial of rituximab and zanubrutinib in indolent B-cell lymphomas from the H. Lee Moffitt Cancer Center (NCT06350318, recruiting) and a phase 2 trial combining epcoritamab, zanubrutinib, and rituximab in relapsed or refractory follicular or marginal zone lymphoma sponsored by Reid Merryman, MD (NCT06563596, recruiting). Several listed records study B-cell lymphomas more broadly. Trial titles describe study questions and do not indicate results.