邊緣區淋巴瘤

Buzzwords → Dx

Diagnostic Criteria

• WHO 5e / ICC 2022: small B-cell lymphoma with marginal-zone differentiation; CD20+ CD5- CD10- CD23- (cyclin D1- excludes MCL).
• Subtypes: extranodal MZL of MALT type, splenic MZL, nodal MZL, splenic diffuse red-pulp small B-cell lymphoma (SDRPL), pediatric MZL.
• Diagnosis by tissue biopsy (gastric biopsy for MALT, splenic biopsy or tissue equivalent for SMZL).
• HP testing (urea breath, stool antigen, biopsy histology + CLO test) for gastric MALT.
• HCV serology for nodal/splenic MZL.

Workup

• Excisional biopsy of involved tissue (or gastric mucosa biopsy for MALT).
• HP testing for gastric MZL; HCV for nodal/splenic.
• PET-CT (less avid than aggressive lymphomas — helpful baseline).
• Marrow biopsy in nodal/splenic MZL.
• HBV/HCV/HIV serology before any rituximab.
• t(11;18) FISH in gastric MALT to predict HP eradication response.
• Splenectomy diagnostic specimen for SMZL is rarely first step now.

Treatment Algorithm

flowchart TD
  A[Confirmed MZL] --> B{Subtype}
  B -- gastric MALT --> C{H. pylori positive?}
  C -- yes, stage IE --> D[HP eradication triple therapy<br>~75-80% remission]
  C -- HP negative or t(11;18)+ --> E[Local RT 24-30 Gy<br>or rituximab]
  C -- failed HP eradication --> E
  D --> F[Surveillance EGD + biopsy<br>q3-6 mo × 2 yr]
  B -- ocular adnexal --> G[Doxycycline trial if C. psittaci<br>or local RT]
  B -- nodal MZL --> H{HCV positive?}
  H -- yes --> I[DAAs to eradicate HCV<br>often → lymphoma response]
  H -- no, low burden --> J[Watch and wait]
  H -- symptomatic / high burden --> K[BR / R-CHOP / rituximab maintenance]
  B -- splenic MZL --> L{HCV positive?}
  L -- yes --> I
  L -- no, asymptomatic --> J
  L -- symptomatic --> M[Rituximab monotherapy<br>or BR<br>or splenectomy if cytopenia + bulky spleen]
  E --> N{R/R disease?}
  K --> N
  M --> N
  N -- yes --> O[Zanubrutinib<br>or BR if not used<br>or PI3K inhibitors]

Pearls / Pitfalls

• Stage IE gastric MALT + HP+ → triple therapy first, not lymphoma chemo. Repeat EGD at 3 mo. Picking R-CHOP for HP+ gastric MALT is the wrong answer.
• t(11;18) API2::MALT1 predicts HP eradication failure — these need rituximab or RT regardless of HP status.
• HCV-driven MZL responds to DAAs (sofosbuvir/velpatasvir etc.) — treat the virus, not the lymphoma, for HCV-associated splenic/nodal MZL with low burden.
• SMZL splenectomy is now rare — rituximab monotherapy first, splenectomy reserved for symptomatic massive spleen with cytopenias unresponsive to rituximab.
• Nodal MZL behaves like FL — same management algorithm (watch / R-Benda / R-CHOP / maintenance).
• Zanubrutinib (BTKi) approved for R/R MZL — MAGNOLIA trial.
• Anti-CD20 + alkylator (BR) > R-CHOP for elderly MZL (lower toxicity, equivalent efficacy in indolent NHL).
• Cutaneous MZL is highly indolent — often local RT or topical / intralesional rituximab.
• Cryoglobulinemia in HCV-MZL — mixed cryos, cutaneous vasculitis, glomerulonephritis; manage HCV first.

Cross-references

• Cytogenetics Atlas — t(11;18) API2::MALT1
• Drug Regimens — BR, R-CHOP, zanubrutinib
• FL — overlap with nodal MZL
• HCL — DDx for SMZL

相關題目

• Q-046 — MZL — gastric MALT with H. pylori
• Q-047 — MZL — t(11;18) gastric MALT
• Q-048 — MZL — HCV-associated splenic MZL

Sources