Primary cutaneous large B-cell lymphomas: relevance of the 2017 World Health Organization classification: clinicopathological and molecular analyses of 64 cases.
Adult
Aged
Aged, 80 and over
Biomarkers, Tumor
/ analysis
Diagnosis, Differential
Female
Germinal Center
/ pathology
Humans
Immunophenotyping
Lymphoma, B-Cell
/ classification
Lymphoma, Follicular
/ classification
Male
Middle Aged
Prognosis
Reproducibility of Results
Skin
/ pathology
Skin Neoplasms
/ classification
World Health Organization
2017 WHO classification
B-cell lymphoma
Hans algorithm
cutaneous lymphoma
leg type
primary cutaneous diffuse large B-cell lymphoma
primary cutaneous follicle centre lymphoma
Journal
Histopathology
ISSN: 1365-2559
Titre abrégé: Histopathology
Pays: England
ID NLM: 7704136
Informations de publication
Date de publication:
Jun 2019
Jun 2019
Historique:
received:
11
10
2018
accepted:
31
01
2019
pubmed:
5
2
2019
medline:
18
12
2019
entrez:
5
2
2019
Statut:
ppublish
Résumé
We applied the 2017 World Health Organization (WHO) classification criteria to categorise a series of 64 primary cutaneous large B-cell lymphomas (PCLBCLs), containing a majority (≥80%) of large cells and a proliferative rate of ≥40%, raising the problem of the differential diagnosis between PCLBCL, leg type (PCLBCL-LT) and primary cutaneous follicle centre lymphoma, large cell (PCFCL-LC). The aims were to determine the reproducibility and prognostic relevance of the 2017 WHO criteria. Morphology and phenotype identified 32 PCLBCLs-LT and 25 PCFCLs-LC; seven cases (11%) remained unclassified. Morphology was less reproducible than immunophenotype. Pertinent markers for the differential diagnosis were MUM1, FOXP1, CD10, and IgM. bcl-2 and bcl-6 were expressed by both PCFCLs-LC and PCLBCLs-LT at substantial levels. Neither Ki67 expression nor p63 expression was of diagnostic value. MYD88 was found to be mutated only in PCLBCLs-LT (n = 22, 69%). According to Hans/Hans modified algorithms, 23 of 25 PCFCLs-LC had germinal centre (GC) status, and the 32 PCLBCLs-LT had non-GC status. Overall survival was poorer for PCLBCLs-LT than PCFCLs-LC (P = 0.0002). Non-GC cases had poorer overall survival than GC cases (P = 0.0007). In PCLBCLs-LT, MYC expression was associated with cutaneous relapses (P = 0.014). When GC/non-GC status was applied to unclassified cases, only a single case remained discordant. Our results support the 2017 WHO classification criteria for PCLBCL diagnosis. The Hans modified algorithm using CD10 and MUM1 distinguished PCFCLs-LC from PCLBCLs-LT with optimal diagnostic value without requiring bcl-6 immunolabelling (poorly reproducible). Rare unclassified cases may constitute a provisionally heterogeneous subgroup for which GC/non-GC status (relevant for prognosis) may guide therapeutic decisions.
Substances chimiques
Biomarkers, Tumor
0
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
1067-1080Informations de copyright
© 2019 John Wiley & Sons Ltd.