BCL6 rearrangement (3q27) by FISH break-apart

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

ID	`BIO-BCL6-REARRANGEMENT`
Type	Biomarker
Aliases	BCL6 rearrangementBCL6 rearrangement (3q27) — FISH break-apart
Status	reviewed 2026-04-25 \| pending_clinical_signoff
Diseases	None declared
Sources	`SRC-NCCN-BCELL-2025`

Biomarker Facts

Biomarker type	gene_fusion
Mutation details	{"functional_impact": "constitutive BCL6 over-expression — blocks differentiation, drives germinal-center program", "gene": "BCL6", "variant_type": "fusion (multiple partners; promoter substitution → over-expression)"}
Measurement	MethodFISH break-apart probe on FFPE biopsy Unitscategorical (positive \| negative)
Related biomarkers	`BIO-DOUBLE-HIT` `BIO-MYC-REARRANGEMENT` `BIO-BCL2-REARRANGEMENT`

Notes

Cross-disease relevance: - **HGBL-DH/THL**: BCL6 rearrangement is the third member of double-/ triple-hit definition. MYC + BCL6 = double-hit (less common than MYC + BCL2). MYC + BCL2 + BCL6 = triple-hit (rarest, worst prognosis). Drives DA-EPOCH-R over R-CHOP. - **DLBCL**: ~20-30% have isolated BCL6 rearrangement — does NOT drive treatment alone (only when combined with MYC). - **FL**: rare ~10%. Required FISH on every newly-diagnosed DLBCL alongside MYC + BCL2 to identify HGBL-DH/THL early.

Used By

Biomarker

BIO-BCL6-IHC - BCL6 IHC (protein expression)
BIO-DOUBLE-HIT - Double-hit (MYC + BCL2 and/or BCL6 rearrangements)

Indications

IND-HGBL-DH-1L-DAEPOCHR - IND-HGBL-DH-1L-DAEPOCHR
IND-HGBL-DH-1L-RCHOP - IND-HGBL-DH-1L-RCHOP

Questionnaires

QUEST-HGBL-DH-1L-STUB - High-Grade B-Cell Lymphoma, Double-Hit / Triple-Hit — first line