HIV-Negative African American Man with Gastrointestinal Kaposi Sarcoma Associated with Adalimumab Treatment for Cardiac Sarcoidosis: A Case Report.

BACKGROUND Adalimumab is a humanized therapeutic monoclonal antibody that blocks tumor necrosis factor-alpha (TNF-a). Kaposi sarcoma is a rare complication associated with adalimumab treatment. It is a cancer with an indolent course and is highly responsive to chemotherapy agents. This report describes the case of a 65-year-old HIV-negative man with gastrointestinal Kaposi sarcoma associated with adalimumab treatment for cardiac sarcoidosis. CASE REPORT A 65-year-old man with cardiac sarcoidosis on adalimumab presented with gastrointestinal bleeding. Endoscopic evaluation revealed Kaposi sarcoma involving the stomach and colon, confirmed by histopathology showing spindle cell proliferation with vascularity and human herpesvirus-8 positivity. HIV testing was negative. Adalimumab was discontinued, and he was treated with paclitaxel. He improved, and the lesions were resolved with treatment as demonstrated in repeat endoscopy. The patient was moved to active surveillance. CONCLUSIONS The endoscopic and clinical presentations of gastrointestinal Kaposi sarcoma are highly variable. In most cases, definitive diagnosis requires endoscopic biopsy and histopathology. Multiple and deep endoscopic biopsies are crucial to avoid false-negative results. Maintaining a high index of suspicion of Kaposi sarcoma in those on immunosuppressants like adalimumab is vital for the timely diagnosis and treatment of this potentially fatal condition. Such patients are usually responsive to withdrawal of the immunosuppressive agent and/or chemotherapy.