Management of Diffuse Large B-Cell Lymphoma as Post-Transplant Lymphoproliferative Disorder in a Kidney Transplant Recipient: A Case Report

Abstract

Background and Clinical Significance: Post-transplant lymphoproliferative disorder (PTLD) is a severe complication of solid organ transplantation, often associated with prolonged immunosuppression. Diffuse large B-cell lymphoma (DLBCL) is the most common subtype. Managing PTLD requires a balance between reducing immunosuppression and preventing graft rejection. Case Presentation: A 41-year-old female kidney transplant recipient developed PTLD eight years post-transplant, presenting with a right submandibular mass. Biopsy confirmed CD20-positive DLBCL. Initial treatment involved reducing immunosuppression and rituximab monotherapy, which failed to prevent disease progression. The patient underwent six cycles of R-CHOP chemotherapy, achieving complete metabolic remission. Relapse occurred twice, with disease progression in the cervical nodes and tonsils. Salvage therapies, including polatuzumab vedotin and rituximab, achieved remission. During a subsequent relapse, loncastuximab tesirine induced metabolic resolution. Compromised renal function limited treatment options and a second renal transplant was delayed, reducing the risk of PTLD recurrence. Conclusions: This case underscores the challenges of managing PTLD in transplant recipients, especially in relapsed/refractory cases. Single-agent rituximab was insufficient, but combination chemotherapy and novel agents like loncastuximab tesirine were effective. Balancing oncologic control and graft preservation remains critical. This case highlights the need for individualized approaches and novel therapies in managing PTLD while addressing the complexities of immunosuppression and organ preservation.

Keywords: diffuse large B-cell lymphoma; loncastuximab tesirine; post-transplant lymphoproliferative disorder.

Figure 1

PET Scan Findings Indicating Disease Progression in PTLD; PET scan performed on 13 September 2020, showing evidence of disease progression with the appearance of a new hypermetabolic right retropharyngeal lymph node (SUV max 13.5) and an interval increase in metabolic activity in cervical and pelvic lymph nodes, consistent with progressive PTLD. This image reflects the initial presentation and the first relapse.

Figure 2

Interim PET Scan Demonstrating Metabolic Resolution in PTLD; PET scan conducted on 20 October 2024, showing interval metabolic resolution of previously hypermetabolic lesions in the left cervical lymph node, tonsillar region, left scapula, and right iliac bone, indicating treatment response in PTLD. The patient subsequently received her fifth cycle of therapy on 24 October 2024. This image reflects the response to loncastuximab tesirine.