January 2026 Research Update

This month, case reports highlighted that splenic marginal zone lymphoma (SMZL) can look similar at first to more aggressive lymphoma when the main sign is an enlarged spleen. The shared message was that examining spleen or lymph node tissue changed the understanding of what was present, sometimes showing aggressive diffuse large B-cell lymphoma (DLBCL) instead of SMZL, or showing both in the same person. This matters because these situations can lead to very different next steps and different expectations for how the illness may behave. [1] [2]

In one report of two people with isolated splenomegaly, spleen removal provided a clear diagnosis: one had SMZL with features suggesting a slow-growing lymphoma, while the other had DLBCL with features suggesting a faster-growing lymphoma. The person with DLBCL received R-CVP chemotherapy after splenectomy and had a complete metabolic remission on PET/CT, showing how different the treatment path can be once the exact lymphoma type is confirmed. A mild rituximab-related lung inflammation was also reported late in treatment, showing that side effects can still occur even when treatment is working. [1]

Another report described a person who had both SMZL and DLBCL (called discordant lymphoma), and deeper genetic testing suggested these two lymphomas did not come from the same original cancer cell. The study found no shared mutations or B-cell receptor patterns between the SMZL and the DLBCL, supporting the idea that they developed independently in this individual. The person was also a hepatitis B carrier, and the authors discussed hepatitis B-related mutation patterns in the DLBCL, but direct proof of virus activity in the tumor was not shown. [2]

For patients, these reports add a clearer picture of why an enlarged spleen and similar symptoms do not always point to the same kind of lymphoma. They support the idea that tissue confirmation (looking at the cells directly) can be important for understanding whether the situation is SMZL, a more aggressive lymphoma like DLBCL, or both, because those labels can lead to very different care plans. This evidence is based on a few individual cases, so it cannot tell how often these scenarios happen, but it does clarify that they can happen and that they may not be predictable from symptoms alone. [1] [2]

A single case this month described a person with SMZL who developed massive chylous ascites (a buildup of milky lymph fluid in the belly), which is an uncommon and very disruptive problem. The key finding was that adding orelabrutinib (a BTK inhibitor, a targeted lymphoma medicine) to rituximab coincided with a rapid and complete clearing of the ascites after prior rituximab alone did not help. For patients, this is an early signal that targeted combinations might be considered in unusual SMZL complications, but it is not proof of how well this works in most people. [3]

In this report, the ascites fully resolved after 2 cycles of orelabrutinib plus rituximab, and imaging later showed no ascites or enlarged lymph nodes. At 6 months, the person was still described as in remission, and no treatment-related side effects were reported. The case also showed how SMZL symptoms can create practical care burdens, including repeated fluid drainage and special nutrition support, and how symptom control can be a major outcome for quality of life. [3]

For patients living with SMZL, this case is most relevant if the illness is causing chylous ascites or if rituximab alone has not controlled symptoms. It suggests that a targeted drug combination may sometimes bring symptom relief quickly, but the evidence is early because it comes from 1 person with only 6 months of follow-up. What remains uncertain is how often this approach works, how long the benefit lasts, and what side effects would look like in a larger group. [3]