Identification of high-risk monomorphic post-transplant lymphoproliferative disorder following solid organ transplantation.

Monomorphic post-transplant lymphoproliferative disorder (M-PTLD) occurring after solid organ transplant histologically resembles aggressive non-Hodgkin lymphomas, with diffuse large B-cell lymphoma being the most common. In a cohort of 40 patients with DLBCL-type M-PTLD, inferior progression free survival (PFS) was observed for Revised International Prognostic Index (R-IPI) >2 (p = 0.01) and high-risk pathologic features (p = 0.02), defined by double expressor lymphoma, MYC rearrangement, or increased copy number of either MYC or BCL2. Overall survival (OS) was inferior in R-IPI >2 (p = 0.002) and high-risk pathologic features (p = 0.003). Combining both R-IPI >2 and high-risk pathologic features resulted in well-delineated good, intermediate, and poor risk groups of DLBCL-type M-PTLD with respect to both PFS and OS (p < 0.001). Our results demonstrate a prognostic role for both the R-IPI score and presence of high-risk pathologic features in DLBCL-type M-PTLD.