Kaposi Sarcoma After Allogeneic Hematopoietic Stem Cell Transplant: A Rare Complication

Kaposi sarcoma is a multicentric angioproliferative neoplasm of lymphatic endothelium-derived cells. Although this malignancy is relatively frequent after solid-organ transplant, it is extremely rare after bone marrow transplantation. Allogeneic stem cell transplantation is associated with severe prolonged immunosuppression; however, a few cases of Kaposi sarcoma after hematopoietic stem cell transplant were previously reported. Here, we report a case of Kaposi sarcoma after haploidentical allogeneic hematopoietic stem cell transplant. The patient was a known case of acute myelogenous leukemia and underwent transplant after relapse. Four months posttransplant, she presented with 3 dark blue or purplish small nodules on her face above the upper lip. Histopathologic study confirmed Kaposi sarcoma. Serum antibody against human herpes virus type 8 was positive. After discontinuation of immunosuppressive medication and cryotherapy for local control, Kaposi sarcoma skin nodules healed with residual pigmented skin lesions. The patient is currently in complete remission for Kaposi sarcoma and cured from acute myelogenous leukemia 36 months after stem cell transplant. Only 14 cases of Kaposi sarcoma after hematopoietic cell transplant have been previously reported in the literature (11 after allogeneic and 3 after autologous hematopoietic stem cell transplant). According to our knowledge from literature review, this case is the first report of Kaposi sarcoma after a haploidentical HLA match transplant.