Gastrointestinal Kaposi Sarcoma as the Initial Presentation of Undiagnosed HIV Infection: A Case of Unexplained Anemia

Kaposi sarcoma (KS) is an angioproliferative malignancy associated with human herpesvirus‐8 (HHV‐8) infection and is strongly linked to immunosuppression, particularly in the setting of human immunodeficiency virus (HIV). Although cutaneous involvement is the most common presentation, visceral disease—especially within the gastrointestinal (GI) tract—may occur and is frequently underrecognized due to its often asymptomatic or nonspecific clinical manifestations. We report the case of a 41‐year‐old male who presented with severe, unexplained anemia without overt GI bleeding. Endoscopic evaluation revealed multiple violaceous, polypoid lesions throughout the stomach, duodenum, and colon. Histopathological examination, supported by immunohistochemical staining positive for CD31, CD34, and HHV‐8, confirmed the diagnosis of KS. Subsequent HIV testing was strongly reactive, with confirmatory HIV‐1 RNA testing subsequently requested. This case highlights the diagnostic challenge posed by GI KS and underscores the importance of maintaining a high index of suspicion in patients presenting with unexplained anemia. Early recognition through comprehensive endoscopic and histopathological evaluation is critical, as it may reveal previously undiagnosed HIV infection and significantly influence clinical management and prognosis.