Complete remission of immunochemotherapy-refractory monomorphic post-transplant lymphoproliferative disorder mediated by endogenous T-cell recovery

unknown cause was found to have an 8.1x6.3cm right iliac fossa mass, adjacent to the transplanted kidney, following investigation into a Proteus urinary tract infection in February 2015. Biopsy demonstrated sheets of large atypical lymphoid cells staining for CD20, CD79a, MUM1, Bcl-2 but not CD10, Bcl-6, or Cyclin D1. EBV-encoded small RNAs (EBER) were strongly positive, confirming EBV positive monomorphic PTLD (diffuse large B cell lymphoma [DLBCL] histology). High levels of EBV DNAemia were evident by qPCR on peripheral blood (142 962 copies/ml). As a result of prior significant cytomegalovirus (CMV) reactivation, and recurrent episodes of bacterial infection of ulcerated skin lesions, significant reductions in immunosuppression (RIS) had already been necessary. At PTLD diagnosis, the patient had been on MMF 500mg twice daily and prednisolone 5mg once daily for the previous year with an estimated glomerular filtration rate of 33mls/min. Past medical history included hyperparathyroidism, hyperlipidaemia, osteoporosis, and obesity. The patient had an ECOG performance status of 3 and required walking aids to mobilise. The large right iliac fossa mass was palpable and invading through the anterior abdominal wall with visible tissue destruction and ulceration. Further large areas of ulceration were evident under both breasts, together with a grade two sacral pressure ulcer. The left chest wall mass was biopsied and was consistent with polymorphic PTLD.