Primary Intrarenal Posttransplant Lymphoproliferative Disorder Detected by Surveillance Protocol Biopsy.

PTLD is estimated to occur in 1–5% of renal transplant recipients. Primary intrarenal localization is extremely rare and is generally diagnosed late, because of ambiguous clinical presentation (2). We detected primary intrarenal lymphoplasmacellular early PTLD in a 5-year-old kidney transplant recipient by renal allograft protocol biopsy. At age 3, the boy underwent renal transplantation from a deceased donor because of end stage renal disease associated with Prune–Belly syndrome. Immunosuppressive therapy included daclizumab, steroids, tacrolimus, and mycophenolate mofetil. Pretransplant EBV serology was negative. According to our protocol, a surveillance renal allograft biopsy was performed, which revealed severe lymphomonocytes infiltration with CD3+ T lymphocytes, CD20+ B lymphocytes, CD79a+ plasma cells, and rare CD68+ monocytes. C4d staining was negative. EBV in situ hybridization showed numerous positive cells, consistent with EBV-associated intrarenal early PTLD