Recommended Citation
Virdi RK, Richards JM, Ehrenpreis ED. Complete Radiographic Response of Disseminated Post-Kidney Transplant Kaposi Sarcoma after Conversion from Tacrolimus to Sirolimus. Presented at Scientific Day; May 20, 2026; Milwaukee, WI.
Abstract
Introduction/Background:
Iatrogenic Kaposi Sarcoma (KS) is a human herpesvirus-8 (HHV-8)-driven angioproliferative neoplasm that can occur after solid-organ transplantation. Post-transplant KS often involves lymph nodes and viscera and is managed primarily by reducing or modifying immunosuppression. Conversion from calcineurin inhibitors (CNI) to mechanistic target of rapamycin (mTOR) inhibitors is frequently employed given potential antitumor and antiangiogenic effects. This report details a unique case of disseminated, predominantly extracutaneous KS, initially concerning for post-transplant lymphoproliferative disorder (PTLD), which achieved complete radiographic response after CNI-tosirolimus conversion alone.
Description:
A woman with end-stage renal disease from congenital renal hypoplasia underwent deceased-donor kidney transplant at age 40 and was maintained on Tacrolimus, Mycophenolate Mofetil, and Prednisone. Three years later, she presented with months of fatigue and night sweats and one day of abdominal pain, nausea, and emesis. Laboratory studies were notable only for mild leukocytosis of 11.5 (reference range 4.2-11 K/mcL). Examination revealed 1-2 cm cervical and supraclavicular lymphadenopathy. CT imaging demonstrated new anterior mediastinal, left para-aortic, and right aortocaval lymphadenopathy, 6-8 mm pulmonary nodules, and multiple hypodense hepatic lesions. Given concern for lymphoma or PTLD, peripheral blood flow cytometry, tumor lysis studies, and Epstein-Barr virus PCR were obtained and results were unrevealing. An IR-guided retroperitoneal lymph node biopsy confirmed KS, with HHV-8-positive lesional cells. After multidisciplinary discussion with the transplant team, Tacrolimus was replaced with Sirolimus. CT at six weeks showed minimal interval change. By four months, mediastinal adenopathy had markedly decreased. By months 6-7, CT and MRI demonstrated complete radiographic resolution of adenopathy, pulmonary nodules, and hepatic lesions with preserved allograft function.
Discussion:
Disseminated iatrogenic KS may lack cutaneous lesions and can mimic PTLD, yet management differs substantially. Early histopathologic confirmation and immunosuppression modifications are essential. In this case, CNI-to-sirolimus conversion led to complete regression without evidence of rejection, supporting mTOR-based strategies as a first-line approach for post-transplant KS.
Presentation Notes
Presented at Scientific Day; May 20, 2026; Milwaukee, WI.
Full Text of Presentation
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Document Type
Poster
Open Access
Available to all.
Complete Radiographic Response of Disseminated Post-Kidney Transplant Kaposi Sarcoma after Conversion from Tacrolimus to Sirolimus
Introduction/Background:
Iatrogenic Kaposi Sarcoma (KS) is a human herpesvirus-8 (HHV-8)-driven angioproliferative neoplasm that can occur after solid-organ transplantation. Post-transplant KS often involves lymph nodes and viscera and is managed primarily by reducing or modifying immunosuppression. Conversion from calcineurin inhibitors (CNI) to mechanistic target of rapamycin (mTOR) inhibitors is frequently employed given potential antitumor and antiangiogenic effects. This report details a unique case of disseminated, predominantly extracutaneous KS, initially concerning for post-transplant lymphoproliferative disorder (PTLD), which achieved complete radiographic response after CNI-tosirolimus conversion alone.
Description:
A woman with end-stage renal disease from congenital renal hypoplasia underwent deceased-donor kidney transplant at age 40 and was maintained on Tacrolimus, Mycophenolate Mofetil, and Prednisone. Three years later, she presented with months of fatigue and night sweats and one day of abdominal pain, nausea, and emesis. Laboratory studies were notable only for mild leukocytosis of 11.5 (reference range 4.2-11 K/mcL). Examination revealed 1-2 cm cervical and supraclavicular lymphadenopathy. CT imaging demonstrated new anterior mediastinal, left para-aortic, and right aortocaval lymphadenopathy, 6-8 mm pulmonary nodules, and multiple hypodense hepatic lesions. Given concern for lymphoma or PTLD, peripheral blood flow cytometry, tumor lysis studies, and Epstein-Barr virus PCR were obtained and results were unrevealing. An IR-guided retroperitoneal lymph node biopsy confirmed KS, with HHV-8-positive lesional cells. After multidisciplinary discussion with the transplant team, Tacrolimus was replaced with Sirolimus. CT at six weeks showed minimal interval change. By four months, mediastinal adenopathy had markedly decreased. By months 6-7, CT and MRI demonstrated complete radiographic resolution of adenopathy, pulmonary nodules, and hepatic lesions with preserved allograft function.
Discussion:
Disseminated iatrogenic KS may lack cutaneous lesions and can mimic PTLD, yet management differs substantially. Early histopathologic confirmation and immunosuppression modifications are essential. In this case, CNI-to-sirolimus conversion led to complete regression without evidence of rejection, supporting mTOR-based strategies as a first-line approach for post-transplant KS.
Affiliations
Advocate Lutheran General Hospital