Human herpesvirus-8 positive iatrogenic Kaposi's sarcoma in the setting of refractory ulcerative colitis

Abstract

Although Kaposi sarcoma (KS) has been more traditionally considered an AIDS-defining illness, it may also be seen in individuals on immunosuppresive therapy. We report a case of a patient who presented to the hospital in the setting of increasingly refractory ulcerative colitis. Computed tomography scan of the abdomen was consistent with sigmoid diverticulititis and blood cultures were positive for Klebsiella. After a course of antibiotics with resolution of infection, a colonoscopy was performed to evaluate his diverticulitis and incidentally revealed a new rectal tumor. Immunohistochemistry showed the tumor was consistent with KS, with cells staining strongly positive for human herpesvirus-8. This case not only illustrates a rare case of KS found in an HIV-negative individual, but it also highlights the importance of considering an alternative diagnosis in a patient refractory to medical treatment. We discuss the management and care of an ulcerative colitis patient diagnosed with KS on immunosuppressive therapy.

Keywords: Kaposi sarcoma; Colorectal cancer; Ulcerative colitis; Inflammatory bowel disease; HIV/AIDS; Human herpesvirus-8

Core tip: Kaposi sarcoma (KS) is associated with human herpes 8 virus infection and is typically an acquired immune deficiency syndrome defining illness. However, KS may also be seen in patients who are on long-term immunosuppression. Review of the literature suggests that isolated gastrointestinal KS is a very rare complication, as there are less than 20 reported cases in the English language literature in ulcerative colitis HIV negative host. Our findings contribute to a small body of literature illustrating the manifestation of primary gastrointestinal KS without skin manifestations in a patient with refractory colitis to medical management.