Background
Post-transplant lymphoproliferative disorder (PTLD) includes a heterogeneous spectrum of disorders, ranging from non-malignant lymphoproliferations to lymphomas.1-5 The clinical presentation of PTLD is variable, usually but not always depending on the location and histopathology.4,6 The vast majority of pediatric PTLD are Epstein Barr virus (EBV)-positive, CD20 positive B-cell lymphoproliferations.6 However, rare subtypes of PTLD have created diagnostic and treatment challenges.4
A few cases of plasmablastic lymphoma (PBL),a rare lymphoma associated with immunodeficiency, have been reported in adult solid organ transplant (SOT) recipients.7-13 PBL after SOT (PT-PBL) in children accounts for a minor fraction of pediatric PTLD; and limited pathological and molecular data have been reported.4,11,12,14 Moreover, it can be difficult to diagnostically differentiate PBL from plasma cell myeloma with plasmablastic morphology,14,15 while the treatments of these two diseases could be different. Here we report two pediatric cases of PBL post SOT and summarize their clinical, genetic and pathological features.