Late Onset Graft Plasmacytoma-Like PTLD Presenting as Acute Hyperglycemia in a Kidney-Pancreas Transplant Recipient

Abstract

Allograft infiltration has been described in up to 20% of all patients with posttransplant lymphoproliferative disorder (PTLD), most representing EBV-positive B-cell lymphomas. Plasma cells are often observed in humoral rejection biopsies, but graft infiltration by plasmacytoma-like PTLD is rare. We report the case of a 54-year-old simultaneous pancreas-kidney transplant recipient (immunosuppression: OKT3, methylprednisolone, cyclosporine, and azathioprine), diagnosed with an IgG-kappa monoclonal gammopathy of undetermined significance eighteen years after transplant. Nine months later, pancreas allograft biopsy performed due to new-onset hyperglycemia (HgA1C 8.6%, C-peptide 6.15ng/mL and anti-GAD 0.9UI/mL) revealed a monotypic plasma cell infiltrate, CD19, CD79a, CD138 positive, with IgG-kappa light chain restriction, and EBV negative. PET-scan FDG uptake was limited to pancreas allograft. Tumor origin could not be established (using DNA microsatellite analysis). Despite treatment with bortezomib and dexamethasone, patient eventually died one month later. This is the first report of a late onset extramedullary plasmacytoma involving a pancreas allograft.

Figure 1

Plasma cells infiltration of pancreas allograft on indication biopsy due to elevation of amylase and lipase. (a–c) Extensive diffuse infiltration and pancreatic tissue replacement with plasma cells observed on H&E ((a): X40; (b): x200; (c): x400). (d) Extensive immunostaining for IgG-kappa chains, x100; (e) absence of lambda staining, x100; (f) immunohistochemical staining were positive for CD79 plasma cells, x100; (g) negative for CD20, x100; and (h) extensively positive for CD138, x100; (i) and (j) Ki67 proliferation index was under 3%.

Figure 2

PET/CT scan (a) and (b): diffuse uptake of FDG and enlargement of pancreas allograft (arrow), without focal lesions. Normal captions of bone marrow, brain, and kidney (arrow heads); (c) serum proteinogram: typical M protein gamma peak; (d) microsatellite analysis (Mentype® Chimera®): DNA from recipient peripheral blood (leukocytes). (e-f) Mixed donor and recipient microsatellite analysis was observed in the DNA extracted from the paraffin block obtained from selected areas with a high infiltration of plasma cells.