Histologic transformation of follicular lymphoma to DLBCL or high-grade B-cell lymphoma (...

Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.

ID	`RF-FOLLICULAR-TRANSFORMATION`
Type	Red flag
Status	reviewed 2026-04-27 \| pending_clinical_signoff
Diseases	`DIS-FL`
Sources	`SRC-ESMO-FL-2024` `SRC-NCCN-BCELL-2025`

Red Flag Origin

Definition	Histologic transformation of follicular lymphoma to DLBCL or high-grade B-cell lymphoma (5-7%/year cumulative risk; lifetime risk 30-40%). Triggers immediate switch from FL-directed therapy (R-CHOP if first treatment, BR, lenalidomide-rituximab, R²-mainentance) to aggressive lymphoma protocol (R-CHOP if rituximab-naive in past 2 years; R-DHAP/R-ICE/R-GDP salvage + ASCT in fit; CAR-T axi-cel/ liso-cel/tisa-cel for transformed-FL per ZUMA-5/ELARA/TRANSCEND-FL).
Clinical direction	intensify
Category	transformation-progression

Trigger Logic

{
  "any_of": [
    {
      "finding": "follicular_transformation",
      "value": true
    },
    {
      "finding": "fl_to_dlbcl_transformation",
      "value": true
    },
    {
      "finding": "fl_to_hgbl_transformation",
      "value": true
    }
  ],
  "type": "composite_score"
}

Notes

Suspect transformation when: rapid LDH rise, asymmetric/explosive nodal growth, new B-symptoms, hypercalcemia, extranodal involvement, PET SUVmax >10 or SUVmax-discordance >5 between sites. Confirm by excisional biopsy of FDG-most-avid lesion. Treatment if rituximab- naive: R-CHOP standard (response ≥80%); rituximab-pretreated within 6-24 months: R-DHAP/R-ICE salvage + ASCT consolidation in fit; rituximab-refractory or post-ASCT: CAR-T per CHAMPLAIN-1, ZUMA-5 (axi-cel transformed-FL ORR 86%, CR 65%; FDA-approved for r/r FL/ transformed FL after ≥2 lines), polatuzumab-BR (POLARIX-style), tafasitamab + lenalidomide. Outcomes have improved markedly with CAR-T era — historical median OS 1-2 yrs now 3-5 yrs in fit CAR-T-eligible.

Used By

No reverse references found in the YAML corpus.