Primary pleural effusion posttransplant lymphoproliferative disorder: Distinction from secondary involvement and effusion lymphoma

Pleural effusion presentation of posttransplant lymphoproliferative disorder (PTLD) is relatively uncommon. Most examples of effusion-based PTLD have been secondary to widespread solid organ involvement, and are associated with an aggressive clinical course. We report on a case of primary effusion PTLD in a 70-yr-old male liver transplant recipient with a history of hepatitis B infection. Cytomorphologically, the pleural fluid specimen showed a monomorphous population of intermediate to large-sized transformed lymphoid cells, with irregular multilobated nuclear contours and readily identifiable mitotic figures. Flow cytometric immunophenotypic studies revealed a CD5-negative, CD10-negative, lambda immunoglobulin light chain-positive, monoclonal B-lymphocyte (CD19-positive/CD20-positive) population. The immunocytochemical stain for CD30 antigen was negative. In situ hybridization study for Epstein-Barr virus (EBV) early RNA (EBER) and Southern blot analysis for EBV terminal repeat sequences were both positive. Southern blot analysis for human herpes virus-8 (HHV-8) was negative. No solid-organ PTLD was identified, and the cytologic results supported the diagnosis of primary effusion PTLD. Immunosuppression was decreased, and 8 mo following the diagnosis of pleural fluid PTLD, the patient was stable and his pleural effusion had markedly diminished. Recognition of primary effusion PTLD and its distinction from PTLD secondarily involving the body fluids and from other lymphomas is important, since the behavior and prognosis appear different.