Multimodal integration of clinic, pathology, and genomics for a rare diagnosis of EBV-positive primary mediastinal large B-cell lymphoma

Primary mediastinal large B cell lymphoma (PMBL) is a rare subtype (6 to 12%) of mature aggressive B-cell lymphoma, accounting for 2–3% of non-Hodgkin lymphomas [1, 2]. PMBL mostly affects young adults presenting with an anterosuperior mediastinal mass which may invade local structures. As with any lymphoma, PMBL is defined by clinical, histopathological, and molecular criteria. Nevertheless, it shares a common oncogenesis with classical Hodgkin’s lymphoma (CHL), which explains the existence of forms that cannot be classified between CHL and diffuse large B-cell lymphoma (DLBCL), known as mediastinal grey zone lymphomas (GZL) [3‐5]. PMBL typically shows a diffuse pattern composed of medium to large sized tumor cells with often abundant pale cytoplasm. In addition, compartmentalizing alveolar fibrosis is commonly observed. PMBL expresses B-cell-lineage markers such as CD20, as well as frequent positivity for CD30 (weak and heterogenous), CD23, PDL1, and MUM1. The distinction between PMBL, CHL, and DLBCL is particularly important, since therapeutic options and prognoses differ widely [1, 2]. …