It is still unclear whether there are clinically exploitable differences in the biology and behaviour of early versus late relapses in diffuse large B-cell lymphoma (DLBCL). The present study aimed to analyse a large population-based DLBCL cohort in order to identify (i) the frequency of late relapses (LR), (ii) parameters influencing the risk of LR, and (iii) the impact of introducing rituximab on the occurrence of LR. The data of 7247 DLBCL patients was obtained from the Danish Lymphoma Group Registry. Patients with LR had a lower International Prognostic Index and better performance score than early relapse (ER) patients. The use of radiotherapy lowered only the rate of ER while the use of rituximab yielded a lower occurrence of both ER and LR (P < 0·0001 and P < 0·0001, respectively), possibly suggesting a longer-lasting biological effect. Additionally, we found a female overrepresentation among LR patients that had received a rituximab-containing first line treatment. It was found that patients with LR had a significantly better 5-year overall survival compared to ER patients. In conclusion, LR was more frequently associated with low-risk features than ER. Furthermore, we found that the use of modern immunochemotherapy regimens in DLBCL lowers the risk of both ER and LR.

Summary We analysed a large cohort of Hodgkin lymphoma (HL) patients in order to characterize: (1) the pattern of late recurrence of lymphoid malignancies (LR) after initial treatment for HL over a 35‐year period; (2) the clinicopathological parameters influencing the risk of LR; and (3) the outcome of patients experiencing LR. We reviewed data of 3350 HL patients diagnosed in Denmark between 1982 and 2018 and registered in the Danish National Lymphoma Registry (LYFO). LR was defined as a recurrence of lymphoid malignancy at least five years after initial diagnosis. LR occurred in 58 patients, with a cumulative incidence at 10, 15 and 20 years of 2.7%, 4.0% and 5.4% respectively. LR was more frequently observed in patients with nodular lymphocyte‐predominant HL (NLPHL) [hazard ratio (HR) 4.5; 95% confidence interval (CI): 2.4–8.4, p < 0.001]. In classical HL (cHL) patients, older age and lymphocytopenia were risk factors for LR with HRs of 1.04 per additional year (95% CI: 1.02–1.06) and 5.6 (95% CI: 2.7–11.5) respectively. Mixed cellularity histological subtype was a risk factor for LR, but only in females, with a HR of 5.4 (95% CI: 1.4–20.4, p = 0.014). In contrast to what was observed in NLPHL, LR in cHL was associated with an almost threefold increased risk of death compared with patients in continuous complete remission. Approximately one fifth (22.4%) of patients with LR experienced a second relapse.

Clinically significant cytomegalovirus (CMV) reactivation is not uncommon in patients with severe immunodeficiency secondary to underlying medical disorders or following aggressive immunosuppressive therapy. However, it is less frequently found in patients with low-grade haematological malignancies after nonintensive chemotherapy. We treated a patient at our centre for stage IVB follicular lymphoma with standard chemotherapy who successively developed CMV colitis associated with a CMV viral load of >3 million copies/ml. Four lines of antiviral treatment were necessary to obtain biochemical remission with undetectable CMV levels, with an initially insufficient response to valganciclovir despite therapeutic pre- and posttreatment levels. Subsequently, our patient also developed an infection with Pneumocystis jirovecii pneumonia (PJP) as further evidence of severe immune compromise. This case report demonstrates the importance of including investigations for less common sources of infection when confronted with a patient with a low-grade haematological malignancy and a pyrexia of unknown origin.