Successful treatment of histiocytic sarcoma and concurrent HIV infection using a combination of CHOP and antiretroviral therapy.

Histiocytic sarcoma (HS) is a rare malignancy of soft tissues with an unknown etiology. The CHOP (cyclophosphamide, vincristine sulfate, doxorubicin hydrochloride and prednisolone) regimen is often adopted as first-line chemotherapy; however, its therapeutic efficacy against HS is usually low. We herein first present the case of a patient with HS who was infected with human immunodeficiency virus-1 (HIV) in whom treatment with a combination of CHOP and antiretroviral therapy (ART) was successful. The patient has been in complete remission for 12 months following the discontinuation of chemotherapy under continuous ART. This case report may help to promote further investigation of both HS and HIV-related malignancy.