Early Complication of Monomorphic B-cell Lymphoma Post Pediatric Cardiac Transplantation

Abstract

<h3>Introduction</h3> Post-transplant lymphoproliferative disorder (PTLD) occurs in 5% to 10% of all pediatric transplant recipients and is an important cause of post-transplant morbidity and mortality. Subtypes include reactive plasmocytic, monomorphic (e.g. B-cell lymphoma), and polymorphic forms. The most common type is monomorphic and is most often associated with Epstein Barr Virus. <h3>Case Report</h3> We describe a case of severe monomorphic B-cell lymphoma PTLD presenting 5 months post-transplant in a 15-year-old male with dilated cardiomyopathy. Both donor and recipient were seropositive for EBV. Peak EBV log post-transplant was 4.08. He received standard induction therapy with anti-thymocyte globulin and routine post-transplant immunosuppression with standard dosing of tacrolimus, mycophenolic acid, and steroid. His post-operative course was complicated by sternal osteomyelitis treated with 3 months of Ertapenem. Early biopsies revealed ACR 1R, but no significant rejection episodes or hemodynamic compromise. He presented with fever, abdominal pain, sore throat, and bilateral ear pain 5 months post-transplant. PET/MRI scan confirmed PTLD within tonsils, adenoids, and a focal hepatic lesion. A monomorphic high grade B-cell lymphoma was identified. Given these findings, his tonsils and adenoids were removed and immunosuppression regimen reduced. He received 4 weekly doses of Rituximab. Repeat PET scan demonstrated increased interval size of the hepatic lesion and new pulmonary nodules. Due to disease persistence, he was treated with four cycles of DA-EPOCH chemotherapy (etoposide, vincristine, doxorubicin, cyclophosphamide, and prednisone). PET scan 7 months post initial presentation demonstrated disease recurrence of the adenoid/tonsillar tissue. Biopsy of the nasal sinus by endoscopy revealed a rare aberrant B-cell population including CD19, CD20, CD22, and CD23. He required 2 additional cycles of chemotherapy and continues to undergo treatment of his PTLD. <h3>Summary</h3> PTLD is a known complication post-cardiac transplantation. Risk factors include EBV-naivety, degree of immunosuppression, and host genetic variations. Treatment is typically reduction in immunosuppression. We describe an extreme case of PTLD not responsive to immunosuppression reduction or rituximab alone and highlight the need for alternative treatment strategies for more advanced disease.