Posttransplant lymphoproliferative disorder encasing transplant renal vein in patient with kidney transplantation

Article information

Kidney Res Clin Pract. 2025;44(4):693-694

Publication date (electronic) : 2025 June 11

doi : https://doi.org/10.23876/j.krcp.25.075

Sang Heon Song^,1,2

¹Department of Internal Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea

²Department of Internal Medicine, Pusan National University School of Medicine, Yangsan, Republic of Korea

Correspondence: Sang Heon Song Department of Internal Medicine and Biomedical Research Institute, Pusan National University Hospital, 179 Gudeok-ro, Seo-gu, Busan 49241, Republic of Korea. E-mail: shsong0209@gmail.com

Received 2025 March 19; Accepted 2025 April 15.

A 44-year-old male underwent a deceased-donor kidney transplant 3 years ago and has been taking prednisolone, tacrolimus, and mycophenolate mofetil as immunosuppressive agents. Focal segmental glomerulosclerosis was diagnosed by kidney biopsy 20 years ago. Owing to progressive kidney dysfunction, the patient started peritoneal dialysis 6 years ago, which continued until the kidney transplant. He had a history of partial nephrectomy for the treatment of clear cell carcinoma of the right kidney 11 years ago. The transplanted kidney function had been stable, with a serum creatinine level of 1.42 mg/dL and an estimated glomerular filtration rate of 60 mL/min/1.73 m². Although he exhibited no complaints or symptoms, we conducted an abdominal computed tomography scan owing to his history of malignancy. The scan revealed an unexpected soft-tissue mass around the transplant kidney’s vessels. Magnetic resonance imaging was performed for a detailed characterization of this mass (Fig. 1). In the T2-weighted image, a 2 × 3-cm soft-tissue mass encasing the transplant renal vein was observed, showing hypermetabolism on positron emission tomography-computed tomography. We performed an ultrasound-guided targeted biopsy for histological confirmation and diagnosed a posttransplant lymphoproliferative disorder (CD20+/CD79a+ B lymphocytes forming aggregates within a background of CD3+/CD45R0+ T cells without Epstein-Barr encoding region staining). Positron emission tomography-computed tomography was conducted to evaluate for other lesions or lymph node involvement, confirming the absence of other malignant lesions and local posttransplant lymphoproliferative disorder without lymph node involvement.

Figure 1.

Radiologic findings of a mass lesion involving transplant kidney vessel.

(A, B) T2-weighted magnetic resonance imaging showing soft-tissue mass (arrows) encasing transplant renal vein. (C) Positron emission tomography-computed tomography imaging showing hypermetabolic mass lesion (arrow) suspicious of malignancy around transplant kidney’s vessel.

Recently, advancements in immunosuppressants and proactive cardiovascular disease management have significantly increased the survival rates of transplant patients. Consequently, the incidence of malignancy, including posttransplant lymphoproliferative disorders, has risen, becoming the most common malignancy in long-term survivors after kidney transplantation. This case presented extranodal involvement of posttransplant lymphoproliferative disorder without lymph node involvement. We planned a reduction in immunosuppressants and localized radiotherapy in collaboration with a hematologist.