A case report of immunosuppression-related Kaposi's sarcoma after autologous stem cell transplantation.

Background: Kaposi's sarcoma (KS) is a tumor formed by angioproliferations driven by Human herpes virus 8 also known as Kaposi's sarcoma-associated herpes virus (KSHV). It is best known as an acquired immune deficiency syndrome (AIDS) defining illness that may be fatal. There are only a few reports of KS after hematopoietic cell transplantation (HCT). This is the first case describing the disappearance of KS with immune recovery after autologous HCT.
Case Presentation: We present the case of a 61-year-old male heterosexual patient of Moroccan origin treated for primary mediastinal non-Hodgkin lymphoma. Because of refractory disease he received multiple lines of chemotherapy prior to autologous HCT. After the second course of low-dose bis-chloroethylnitrosourea, etoposide, cytarabine, melphalan (BEAM) the patient developed several round blue skin lesions. A biopsy was performed, showing many small vessels and positive immune histochemical staining for Human herpes virus 8 (HHV-8), confirming diagnosis of KS. Human immunodeficiency virus testing was negative and work-up showed that there were no visceral lesions. When KS are limited to the skin, prognosis is usually better. The extensive chemotherapy resulted in an important immunosuppression; on day 105 after autologous HCT CD4(+) count was 82/mm(3). Since KS were limited to the skin and attributed to severe immune suppression a watchful waiting strategy was adopted even though in the first months after autologous HCT new skin lesions appeared. With immune recovery (CD4(+) count > 200/mm(3)) 277 days after transplant, skin lesions faded.
Conclusion: Kaposi's sarcoma remains a rare tumor that should be thought of in any patient whose immunity is down. If immune recovery is expected and disease is limited to the skin, a watchful waiting strategy can be more rewarding than intensive chemotherapy.