Abstract Background: De novo malignancies are a significant cause of mortality in liver transplant recipients. This systematic review and meta-analysis synthesized evidence regarding the incidence of de novo lymphoid and hematological malignancies. Methods: Observational studies that compared the prevalence of hematologic malignancies in liver transplant recipients with the general population were included following searches using relevant keywords in ScienceDirect, PubMed, and Google Scholar. The methodological quality of the included studies was evaluated using the Newcastle–Ottawa Scale, with the overall quality converted into the Agency for Healthcare Research and Quality standards (i.e., poor, fair, and good). The generic inverse variance method was used to pool the standardized incidence ratio (SIR) as risk ratios and their 95% confidence intervals (CI) Results: A total of 32 studies were included. Following liver transplantation, post-transplant lymphoproliferative disorder was the most common hematologic malignancy (SIR: 23.06, 95% CI: 4.08–130.04; P < 0.0004), while multiple myeloma was the least common (SIR: 3.10, 95% CI: 2.22–4.34; P < 0.0001). The incidence of non-Hodgkin lymphoma (SIR: 11.05, 95% CI: 8.54–14.28; P < 0.0001) was higher than that of Hodgkin lymphoma (SIR: 7.59, 95% CI: 5.63–11.23; P < 0.0001). The overall risk of hematologic malignancies in liver transplant recipients was significantly higher than in the general population (SIR: 5.83; 95% CI: 2.35–8.05; P < 0.0001). Conclusion: This meta-analysis found that after liver transplantation, post-transplant lymphoproliferative disorder (PTLD) is the most prevalent hematological malignancy. Although PTLD and other hematologic malignancies are less prevalent than solid organ nonlymphoid tumors, they significantly affect liver transplant recipient outcomes. Further research is necessary to identify strategies for managing these complications. Registration: PROSPERO (Reg. no.: CRD420251131279)
Gadour et al. (2026) studied this question.