Distinctive Clinicopathologic Features of Monomorphic B-cell Post-transplant Lymphoproliferative Disorders in Children.

Post-transplant lymphoproliferative disorders (PTLDs) comprise a heterogeneous group of Epstein-Barr virus (EBV)-positive or negative lymphoid or plasmacytic lesions in solid organ or hematopoietic stem cell (HSC) transplant recipients. Although PTLDs in adults have been extensively studied, the clinicopathologic features of monomorphic B-cell PTLD in children, particularly EBV-negative forms, are still poorly understood. We retrospectively reviewed all our pediatric cases of monomorphic B-cell PTLDs diagnosed in the past 10 years. Clinical data were reviewed. Pathologic data including histologic types and EBV status were analyzed. Additional immunohistochemical stains, FISH studies, and 4 of 18 cases were EBV-negative. All 4 EBV-negative cases were strikingly confined to the gastrointestinal (GI) tract or abdominal lymph nodes, while tumors in EBV-positive cases were found at various anatomic sites; 2 of 4 EBV-negative cases carried mutations in We report that monomorphic B-cell PTLDs in children have distinctive clinical and pathological features. More studies are needed to clarify whether and how much these pediatric PTLDs differ from their adult counterparts.