Aim CD30+ diffuse large B-cell lymphoma (DLBCL) has emerged as a new immunophenotypic variant of de novo DLBCLs. However, the prevalence of CD30 positivity is variable according to different studies, and the prognostic significance of CD30 is also controversial. This study aimed to investigate the positive expression rate and prognostic impact of CD30 in de novo DLBCLs and try to find the correlated influences.

Methods A total of 241 patients with de novo DLBCL in east China from 2008 to 2015 were included to investigate the prevalence, clinicopathological features and outcomes of CD30+ de novo DLBCLs. Immunohistochemical evaluation for CD10, CD30, BCL2, BCL6, MUM1/IRF4, MYC and Ki67, and fluorescence in situ hybridisation for MYC and BCL2 gene alterations were performed.

Results Using a >0% threshold, CD30 expression was detected in approximately 10% patient with de novo DLBCL. These predominately presented with centroblastic or anaplastic morphological patterns, less frequently showing immunoblastic morphology or ‘starry sky’ pattern, mutually exclusive with MYC gene rearrangement, and negatively associated with BCL2 protein expression. CD30 expression was associated with a favourable prognosis of patients’ outcomes. However, the multivariate analysis revealed that it was not an independent prognostic factor in de novo DLBCLs. The impact of CD30 might be influenced by the international prognostic index and the expression of MYC and BCL2 proteins.

Conclusion CD30+ DLBCL may be a subset of de novo DLBCLs with characteristic clinicopathological features, but the prognostic role of CD30 is limited.