Posttransplant lymphoproliferative disorder in pediatric patients: Survival rates according to primary sites of occurrence and a proposed clinical categorization

Posttransplant lymphoproliferative disorder ( PTLD ) is a devastating complication of organ transplant. In a hospital‐based registry, we identified biopsy‐proven cases of PTLD among children during a 15‐year period and reviewed trends in PTLD rates, the sites of involvement, and the associated survival rates. Cases that were included had at least 1 year of follow‐up after the diagnosis of PTLD . We studied 82 patients with first‐episode PTLD . Median age at diagnosis was 6.4 years (IQR 3.2‐12.3 years). The most frequent PTLD sites were tonsillar/adenoidal (T/A [34%]) and gastrointestinal (32%), followed by miscellaneous (defined as less common sites including central nervous system , kidney, lung, and soft tissue [12%]), lymph node (11%), and multisite (11%). Kaplan‐Meier survival curves showed that T/A PTLD was associated with decreased all‐cause mortality compared with PTLD at other sites (log‐rank 0.004), even after adjustment for histological subtype ( P  = .047). PTLD ‐related mortality was also decreased among T/A PTLD (log‐rank 0.012) but showed a trend toward significance only after adjustment for histological subtype ( P  = .09). Among first episodes of PTLD , T/A PTLD was associated with a survival advantage compared with PTLD at other sites, even after adjustment for potential confounders. Based on our observations, we propose a clinical categorization of PTLD according to anatomical site of occurrence.