Comparison of clinicopathological and genetic features of PTFL, LBCL-IRF4, and TFL
| . | PTFL∗ . | LBCL-IRF4† . | TFL‡ . |
|---|---|---|---|
| Median age, y (range) | 15 (5-31) | 12 (3-28) | 4 (3-16) |
| M:F | 20:1 | 1.5:1 | --- |
| Stage at presentation | 100% localized Stages I-II | 89% localized Stages I-II | Mostly stage IE |
| Site of presentation | Head and neck LN Rare cases reported in conjunctiva | Waldeyer ring, mainly tonsils GI tract | Testis |
| Recommended treatment | Surgical excision, watch-and-wait 100% CR | 25% surgical excision only; 75% systemic treatment§ 100% CR | Orchiectomy only||; watch-and-wait 100% CR |
| Morphology | Large serpiginous, ill-defined follicles with attenuated lymphoid cuffs, and a prominent starry-sky pattern. Monotonous medium- to large-sized blastoid cells. Some cases with centroblastic morphology. | Large, closely packed expansile follicles predominantly composed of medium-sized blasts with fine chromatin, inconspicuous nucleoli, and scant cytoplasm. Some cases with centroblastic morphology¶ | Back-to-back atypical small follicles composed predominantly of centroblasts admixed with centrocytes associated with well-formed FDC meshworks |
| Diffuse areas | Negative | 41% purely diffuse 28% follicular/diffuse 31% purely follicular | Often observed, usually focal74 |
| Starry-sky pattern | Characteristic finding | Negative | Negative |
| CD10+ | 100% (strong) | 55% | Some negative cases |
| BCL2+ | 18% | 60% | Usually negative |
| BCL6+ | 100% (strong) | 100% | 100% |
| IRF4/MUM1+ | Negative | 100% | Negative |
| BCL2-R | Negative | Negative | Negative |
| BCL6-R | Negative | 11% | One case reported74 |
| IRF4-R | Negative | 100% ∼10% cryptic | Negative |
| Genetic features | Mutations: TNFRSF14 (54%) MAP2K1 (40%-50%) IRF8 (30%) | Mutations: IRF4 (85%), BCL6, and NF-κB pathway genes | Limited data available |
| . | PTFL∗ . | LBCL-IRF4† . | TFL‡ . |
|---|---|---|---|
| Median age, y (range) | 15 (5-31) | 12 (3-28) | 4 (3-16) |
| M:F | 20:1 | 1.5:1 | --- |
| Stage at presentation | 100% localized Stages I-II | 89% localized Stages I-II | Mostly stage IE |
| Site of presentation | Head and neck LN Rare cases reported in conjunctiva | Waldeyer ring, mainly tonsils GI tract | Testis |
| Recommended treatment | Surgical excision, watch-and-wait 100% CR | 25% surgical excision only; 75% systemic treatment§ 100% CR | Orchiectomy only||; watch-and-wait 100% CR |
| Morphology | Large serpiginous, ill-defined follicles with attenuated lymphoid cuffs, and a prominent starry-sky pattern. Monotonous medium- to large-sized blastoid cells. Some cases with centroblastic morphology. | Large, closely packed expansile follicles predominantly composed of medium-sized blasts with fine chromatin, inconspicuous nucleoli, and scant cytoplasm. Some cases with centroblastic morphology¶ | Back-to-back atypical small follicles composed predominantly of centroblasts admixed with centrocytes associated with well-formed FDC meshworks |
| Diffuse areas | Negative | 41% purely diffuse 28% follicular/diffuse 31% purely follicular | Often observed, usually focal74 |
| Starry-sky pattern | Characteristic finding | Negative | Negative |
| CD10+ | 100% (strong) | 55% | Some negative cases |
| BCL2+ | 18% | 60% | Usually negative |
| BCL6+ | 100% (strong) | 100% | 100% |
| IRF4/MUM1+ | Negative | 100% | Negative |
| BCL2-R | Negative | Negative | Negative |
| BCL6-R | Negative | 11% | One case reported74 |
| IRF4-R | Negative | 100% ∼10% cryptic | Negative |
| Genetic features | Mutations: TNFRSF14 (54%) MAP2K1 (40%-50%) IRF8 (30%) | Mutations: IRF4 (85%), BCL6, and NF-κB pathway genes | Limited data available |
CR: complete remission; GI: gastrointestinal; FDC, follicular dendritic cells; M:F, male to female ratio; LN, lymph nodes; R: rearranged.
Data obtained from references 42, 78 and 93; 75 patients in total.
Data obtained from references 89, 91, 92, 93 and 94; 61 patients in total.
Data obtained from references 93, 74, 95, 96, 97, and 98; 20 cases in total.
Cases with purely follicular growth pattern and stage I disease do well only with surgical excision, most patients still receive systemic treatment.
Patients were previously treated with systemic therapy after orchiectomy. This is no longer recommended.
Aberrant expression of CD5 is well recognized.