Non-Hodgkin's Lymphoma Manifest as Gingival Hyperplasia in a Renal Transplant Recipient
A male, 41 years old, visited the clinic in April 2002 after experiencing bleeding, pus discharge, edema, and pain of the gingivae over the previous three months (). He had previously been diagnosed with end stage renal failure because of IgA nephropathy. Additionally, continuous ambulatory peritoneal dialysis was initiated in January 1994. He underwent a kidney transplantation with 40 minutes of cold ischemia in November 1995. His brother, who had haploid-identical HLA typing, was the donor. The patient was maintained on medication consisting of 75 mg of cyclosporine twice daily, 12 mg of deflazacort once daily, and 750 mg of mycophenolate mofetile (MMF) administered twice daily. His post-operative progress was good until he developed gingival bleeding, discharged pus, and pain.\nThree months before entering our clinic, he was admitted to the outpatient dental clinic for treatment of hyperplastic gingivae (which at that time was considered to have been induced by cyclosporine). The lesion, however, did not improve despite scaling, oral antibiotics, and a reduction in the cyclosporine doses. Moreover, the gingival hyperplasia exhibited focal papillary growth and bled in response to light pressure. He had also lost 5 kg of body mass over the preceding six months.\nA laboratory examination, including complete blood counts, blood chemistry, and urinary analysis, revealed that his hemoglobin concentration was 11.1 g/dL, blood urea nitrogen concentration was 27.5 mg/dL, and creatinine concentration was 1.46 mg/dL. The white cell count was 6370/µL while the platelet count was 256,000/µL. Other variables remained normal. Serum cyclosporine levels were low ().\nWe did a biopsy of the lesion to identify other potential causes. The biopsy established the presence of leukemic cell infiltration including a malignant lymphoma or histiocytic tumor (). Muramidase and immunohistochemical stains specific for LCA (), L26 (), UCHL1, and CD68 revealed a large diffuse B cell type of malignant lymphoma. The latent membrane protein for the Epstein-Barr virus (EBV-LMP) immunohistochemical stain was positive ().\nIn the initial stage of the lymphoma, computed tomography (CT) scan of the neck indicated a 2×1.5 cm enlarged lymph node present in the right submandibular area several enlarged lymph nodes were also in the bilateral parapharyngeal space. Lung and intestinal CTs showed no evidence of lymphadenopathy. A bone marrow aspiration and biopsy revealed a slight hypocellularity (30%) and normal maturation. The final stage of the lymphoma was stage II (B) according to the Ann Arbor Staging System.\nAdministration of MMF and cyclosporine was stopped, but prednisolone treatment was continued. The patient started chemotherapy with a CHOP regimen of 1087 mg of cyclophosphamide (750 mg/m2), 72 mg of doxorubicin (50 mg/m2), 2 mg of vincristine, and 100 mg of prednisolone. After three serial CHOP chemotherapies, a neck CT showed a marked regression of the right submandibular lesion but no clearly enlarged lymphadenopathy in the other neck areas. CHOP therapy and external radiotherapy of the gingivae was performed a total of six times.\nIn 2004, the patient's gingivae were normal upon examination, and CT scans could not detect lymphadenopathy. Presently, his renal function is good and is treated by daily doses of 100 mg azathioprine and 7.5 mg prednisolone.