FL: The Lore
EASY: This is the most common indolent B-cell Non-Hodgkin Lymphoma, accounting for approximately 20-25% of NHL in Western countries
What is follicular lymphoma?
This is the hallmark translocation of follicular lymphoma
What is t(14;18)(q32;q21)?
This prognostic index uses age, hemoglobin, LDH, number of nodal areas, and stage to stratify patients with FL.
What is FLIPI?
For an asymptomatic patient with advanced-stage FL who has no indication for treatment, this management strategy is a category 1 NCCN recommendation.
What is active surveillance (watch and wait)?
These clinical changes in a patient with previously indolent FL should raise suspicion for histologic transformation: rapidly enlarging asymmetric nodes, new B symptoms, and rising LDH.
What are clinical red flags for transformation to DLBCL?
These two markers are typically positive in FL and help establish its germinal center B-cell phenotype
What are CD10 and BCL6?
Overexpression of this anti-apoptotic protein allows FL cells to survive when normal germinal-center B cells would undergo programmed cell death.
What is BCL2?
This set of criteria helps determine whether a patient with advanced-stage FL has high tumor burden warranting treatment rather than observation.
What are the GELF criteria?
This local treatment is preferred for stage I or contiguous stage II FL according to our lecture.
What is involved-site radiation therapy (ISRT)?
A PET scan shows one lymph node with markedly higher FDG uptake than the patient's other FL sites. This is the next diagnostic step, targeting the most FDG-avid safely accessible site.
What is a biopsy of the suspicious site? PET helps select the target but cannot diagnose transformation by itself.
This biopsy method is preferred for diagnosing lymphoma bc it preserves nodal architecture and allows accurate histologic grading
What is an excisional lymph node biopsy?
This is the most commonly mutated gene in FL in your lecture, encoding a histone H3K4 methyltransferase.
What is KMT2D?
When defined appropriately this post-frontline clinical event, not a baseline score, identifies a follicular lymphoma group with strikingly inferior survival after immunochemotherapy.
What is POD24?
For high-tumor-burden advanced-stage FL, this preferred chemoimmunotherapy approach combines bendamustine with an anti-CD20 antibody.
What is bendamustine plus rituximab or obinutuzumab?
This acquired rearrangement is substantially more common in transformed FL than in typical FL and is an important finding to assess by FISH.
What is a MYC rearrangement?
What is Grade 3 FL (remember 3A is defined as >15 centroblasts/HPF and 3B is sheets of centroblasts without centrocytes)
This gene rearrangement is NOT common in FL and if you see it, you should likely consider the disease to be a high grade B cell lymphoma instead
What is MYC rearrangement?
This newer prognostic model, described in our FL lecture, uses age plus hemoglobin, LDH, beta-2 microglobulin, and WBC count to predict early progression
What is FLIPI24?
A patient with FL has a 7.5 cm tumor mass, even though they report no B symptoms. According to the GELF criteria, does this meet a high tumor burden threshold that may indicate treatment?
What is yes? A single nodal or extranodal mass meeting the 7.5 cm or greater threshold qualifies.
These two alterations affect tumor-suppressor and cell-cycle pathways and are associated with transformation in the lecture.
What are TP53 mutation and CDKN2A/B loss? MYC rearrangement or dysregulation is another key transformation-associated event.
This prognostic feature is present in approximately 60–70% of patients with follicular lymphoma at diagnosis, even though the disease may otherwise appear clinically indolent
What is bone marrow involvement?
Sounds like you're about to get knocked out, but this model is used to demonstrate that the t(14;18) mutation, despite being the hallmark event, is not sufficient enough alone for lymphomagenesis
What is the Multi-hit model?
These two chromosomal abnormalities are highlighted as poor prognostic factors associated with an increased risk of transformation to DLBCL.
What are del(6q23–26) and del(17p), the latter involving loss of TP53?
For a patient with advanced-stage, low-tumor-burden FL who needs treatment, this anti-CD20 regimen is listed as preferred by guidelines
What is rituximab 375 mg/m² weekly for four weeks?
When biopsy cannot immediately be obtained, this clinical scoring system uses elevated LDH, focal nodal enlargement of at least 3 cm, hemoglobin below 12 g/dL, and poor performance status. PPV of 96.4% at a score of at least 2.
What is the Transformation Scoring System (TSS)? It estimates transformation probability; it does not replace biopsy.