Primary Refractory Discordant Diffuse Large B-Cell and Classical Hodgkin Lymphoma

Abstract

Discordant lymphomas are defined as two or more distinct pathological lymphomas occurring in the same patient. Due to the rarity of discordant lymphomas, which is due in large part to the difficulty in establishing the diagnosis, the literature is limited to small case series and case reports. Consequently, guidelines on therapeutic strategies are lacking. This article presented a case of primary refractory discordant large B-cell lymphoma and classic Hodgkin lymphoma in a young man based on cervical node and mediastinal mass biopsy, respectively. This case illustrates the difficulty in establishing the diagnosis, which ultimately warranted a high index of clinical suspicion and pursuit of multiple sequential biopsies, as well as a novel treatment strategy using an immune checkpoint inhibitor.

Keywords: Checkpoint inhibitor; Classical Hodgkin lymphoma; Discordant lymphoma; Large B-cell lymphoma.

Figure 1

Clinical-pathologic summary of events. LBCL: large B-cell lymphoma; CHL: classical Hodgkin lymphoma; DA-EPOCH-R: dose-adjusted EPOCH-R; DLBCL: diffuse large B-cell lymphoma; PET/CT: positron emission tomography/computed tomography; EPOCH-R: etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab; GDP: gemcitabine, dexamethasone, cisplatin; CAR: chimeric antigen receptor.

Figure 2

First instance of lymphoma shown in a biopsy of a left neck lymph node. The revised diagnosis is of a diffuse large B-cell lymphoma of germinal center phenotype (CD10^-, BCL6⁺, MUM1^-). The architecture of the lymph node parenchyma is effaced by sheets of large rounded lymphoid cells (H&E stain × 400). There is diffuse immunoreactivity for CD20 and PAX5, and patchy staining for CD30 (× 200, insert: low power). There was no positivity for CD15 or CD23. Tumor cells are PDL1⁺. H&E: hematoxylin and eosin; PDL1: programmed death ligand-1; BCL6: B-cell lymphoma 6; MUM1: multiple myeloma 1; PAX5: paired box 5.

Figure 3

Second instance of lymphoma shown in a biopsy of a mediastinal mass. The revised diagnosis is of a classic Hodgkin lymphoma. There are scattered large cells with Reed Sternberg and Hodgkin morphology (arrows) scattered in an eosinophil rich mixed lymphoid background (H&E stain, × 400). Tumor cells (arrows) that do not show immunoreactivity for CD20 (× 400), are positive for PAX5 (× 400), CD30 (× 400) and negative for CD15 (insert, background inflammatory cells positive). Tumor cells are PDL1⁺. H&E: hematoxylin and eosin; PDL1: programmed death ligand-1; PAX5: paired box 5.