A rare complication of hematopoietic stem cell transplantation: Kaposi sarcoma

Abstract

Background: Kaposi sarcoma is a neoplasm characterized by mucocutaneous and visceral angioproliferations that requires infection with human herpes virus (HHV)-8 for its development. The iatrogenic variant is seen in patients undergoing immunosuppressive therapy, especially in organ transplant recipients. Kaposi sarcoma after hematopoietic stem cell transplantation is a rare complication with only 18 cases reported previously. Case report: Here we present the case of a 58-year-old male patient treated for acute B lymphoblastic leukemia. For his second relapse, he was started on hyper-CVAD regimen after which he underwent an allogeneic stem cell transplant from human leukocyte antigen-identical unrelated donor. Prompt donor engraftment was achieved. The only immunosuppressive he received was cyclosporin A, which was stopped 90 days after the transplantation. He received multiple blood transfusions because of his ongoing anemia. He was diagnosed with direct Coombs positive hemolytic anemia caused by subgroup mismatch (anti-E and anti-Jka) on day +219. He was started on prednisone. He developed small purple papillary lesions on his right leg and penis on day +255 while receiving steroid therapy. This coincided with the high levels of cytomegalovirus DNA in his whole blood, which was also positive for HHV-8 DNA when analyzed with PCR. A punch biopsy of the lesion was obtained which was reported to be Kaposi sarcoma with positive immunohistochemical staining for HHV-8. Both the recipient and the donor were seronegative for HIV before the transplant; recipient remained seronegative. CT of the chest and abdomen excluded visceral involvement. Ultrasonography revealed an enlarged lymph node that was confirmed to be Kaposi sarcoma via core biopsy. Since there were no visceral involvement, we only considered local therapies. Immunosuppressive therapy was reduced but could not be stopped because of his autoimmune hemolytic anemia. Radiation therapy was administered, one course for the lesion on the right leg and another for the inguinal lymph node. Lesions treated with radiation regressed, however non-irradiated lesions continued to progress, eventually involving his trunk,left leg, and face; each less than 1cm in diameter. Cryotherapy and topical 5-Fluorouracil were utilized for the skin lesions. Lesions regressed but never fully healed. He presented to the emergency department on day +387 with fever andproductive cough. His sputum cultures produced Klebsiella pneumonia, so he was admitted and started on antibacterial treatment. During his stay, he developed CMV viremia. While under treatment he underwent septic shock and admitted to the intensive care unit. The patient died of cardiopulmonary arrest during his stay in the intensive care unit. The major risk factors for our patient were the immunosuppressive therapy and concurrent cytomegalovirus infection. Multiple blood transfusions he received might have been responsible for a primary infection with HHV-8.Conclusion: In conclusion, Kaposi sarcoma is a rare complication of hematopoietic stem cell transplantation that should be thought of in any immunocompromised patient with unusual mucocutaneous lesions.