Rejection Versus Posttransplantation Lymphoproliferative Disorder in a Renal Transplant Recipient

Histopathologic findings in kidney biopsy specimen. (A) Mixed inflammatory cell infiltrate with numerous eosinophils, eosinophilic tubulitis (arrows), and tubular injury. (B) Interstitial inflammatory infiltrate including large atypical cells. (Inset) Cells with (left) irregular nuclear contour and (right) macronucleolus. (C) Vascular findings at edge of necrosis: (∗) vessel with fibrinoid change, (arrowheads outline) artery with lumen occluded by flocculent material with lymphocytes, and (arrow) interstitial mitotic figure in histiocyte-rich area. (D) Immunohistochemical staining of serial sections shows the infiltrate is composed of a majority of (left) small CD3-positive T cells and (right, matched field) a minority of small CD20 positive B-cells. (E) Immunohistochemical staining of serial sections shows (left) CD30 stains clusters of cells, including large cells, whereas (right) PAX5 highlights few B cells, including (matched field) a rare cell with large nucleus. (F) Epstein-Barr virus (EBV) in situ hybridization highlights numerous infiltrating cells; positive signal is blue with red counterstain (original magnifications ×400).

Histopathologic findings in lung biopsy and allograft nephrectomy specimens. (A) Lung with dense monomorphic lymphoid infiltrate effaces pulmonary architecture. (B) CD20 staining shows B-cell phenotype. (C) Allograft nephrectomy with (lower left) glomerular ischemia, (upper right) prominent oxalate crystals, tubular atrophy, interstitial fibrosis, and non-atypical lymphocytes. (D) Chronic allograft arteriopathy with scant lymphoid infiltrate (original magnification: [A-C] ×400; [D] ×200).