Cutaneous Post-transplant Lymphoproliferative Disorder.

Area of Science:

• Oncology
• Immunology
• Dermatology

Background:

• Post-transplant lymphoproliferative disorders (PTLD) are a serious complication in immunosuppressed transplant recipients.
• PTLD typically involves T- or B-cell proliferation and can affect various organs, often at extranodal sites.
• Cutaneous manifestations of PTLD are uncommon and present with diverse clinical features.

Observation:

• A 36-year-old male cardiac transplant recipient developed a painless, three-month-old ulcer on his right lower leg.
• Skin biopsy revealed atypical lymphoid infiltrate positive for B-cell markers (PAX5, CD20, MUM1), EBV, and a high proliferation index (Ki-67 70%).
• FDG-PET scan indicated PTLD involvement in the leg ulcer, tibia, and inguinal lymph node.

Findings:

• The patient was diagnosed with monomorphic B-cell PTLD, consistent with diffuse large B-cell lymphoma, non-germinal center subtype.
• Treatment involved azathioprine cessation and rituximab (anti-CD20 antibody) therapy.
• The patient achieved clinical resolution of the ulcer and negative FDG-PET scan, with no recurrence to date.

Implications:

• This case highlights a rare presentation of PTLD with isolated cutaneous involvement.
• Successful treatment with immunosuppression adjustment and rituximab underscores the importance of prompt diagnosis and intervention.
• PTLD can emerge years post-transplant, emphasizing the need for vigilant monitoring and early management in transplant recipients.