Abstract 2662Posttransplant Lymphoproliferative Disorder (PTLD) is a rare complication of kidney transplantation that often arises due to reactivation of the Epstein-Bar Virus (EBV). Given the rarity of this disease, a full understanding of its presentation and optimal therapies has yet to be determined. Out of the 3160 patients who received a kidney transplant at the Hospital of the University of Pennsylvania between October 1987 and December 2010, we provide a retrospective analysis of 68 patients who developed PTLD. These patients were 82% Caucasian, 62% male, and 9% combined kidney and pancreas transplant patients. The most common underlying diseases leading to transplantation were glomerulonephritis (26%) and diabetes mellitus (17%). Most patients received a kidney from an unrelated donor (74%) and experienced one or more rejection episodes prior to PTLD diagnosis (59%). The median age at PTLD diagnosis was 48 yrs (range 17–76 yrs), and the median time from transplantation to diagnosis was 3 yrs (range 6 days– 25 yrs). PTLD histology consisted of 48% monomorphic, 37% polymorphic, 7% plasmacytoma, 4% T cell, and 3% Hodgkin lymphoma. At diagnosis, patients were taking steroids (96%), cyclosporine (53%), tacrolimus (35%), azathioprine (52%), and/or mycophenolate mofetil (28%). Common initial PTLD symptoms include fever (48%), pain (42%), weight loss (33%), fatigue (33%), and mass (24%). The disease commonly presented in lymph nodes (38%), kidney allograft (29%), and/or GI tract (18%). Most PTLD cases were diagnosed at stage 1 (43%) or stage 4 (31%). Laboratory analyses reveal that 62% of patient tumors tested positive for EBV and 61% of patients had elevated LDH levels. Common PTLD therapies included reduction of immunosuppression (88%), treatment with rituximab (31%), surgery (29%), and/or radiation therapy (9%). Reduction of immunosuppression alone led to CR (50%), PR (8%), SD (4%), and PD (38%). Of the 68 patients, 21 (31%) ultimately died a PTLD related death.Interestingly, PTLD patients under age 40 were more likely to have allograft involvement (p=0.007) and a polymorphic histology (p=0.007). Furthermore, allograft involvement tended to occur sooner after transplant (p=0.0001) and those with allograft involvement were more likely to present with allograft failure (p= 0.0001). Compared to monomorphic PTLD, polymorphic PTLD was more likely to be EBV positive (82% vs 51%, p=0.03) and have a lower chance of PTLD-related death (15% vs 40%, p=0.03). Finally, patients with allograft PTLD were more likely to have a polymorphic histology (80%, p<0.001). In summary, PTLD occurs in about 2% of kidney recipients and is typically EBV-associated. EBV positive PTLD is more common in younger recipients, frequently presenting with polymorphic histology in the allograft and appears to have a better prognosis. Disclosures:No relevant conflicts of interest to declare.