Kaposi Sarcoma: A Case of Mistaken Identity in an Immunocompetent Healthy Male.

Background: Kaposi's sarcoma (KS) is a low-grade vascular neoplasm associated with human herpesvirus-8 (HHV-8), frequently occurring in immunocompromised patients, particularly those with human immunodeficiency virus (HIV)Its clinical presentation varies from innocuous-appearing vascular skin lesions to visceral involvement. There are case reports of a rare type of KS which mimics pyogenic granulomas particularly on the feet though reports of KS in immunocompetent, healthy individuals are rare. In this report we share the case of an immunocompetent, healthy young adult male who presented with a lesion concerning for pyogenic granuloma that was found on pathology to be KS. Case report: We report the case of an HIV-negative, immunocompetent young adult Latin American male who presented with a painful, rapidly growing lesion between his first and second toe. The lesion was initially diagnosed as a wart. After failing salicylic acid and cryotherapy the lesion had a more vascular appearance, as shown in Figure 1. Excisional biopsy was obtained with pathology revealing KS, which was confirmed via latency-associated nuclear antigen (LANA) immunostaining. HIV testing was obtained at three time points, all of which were negative. Patient denied high risk behaviours including sex with men and intravenous drug use. Re-excision for margins was completed with dermatology and pathology again confirmed KS with localized disease. Patient received definitive treatment from dermatology and oncology, emphasizing the multidisciplinary nature of KS management. Conclusion: KS should be included in the differential diagnosis for vascular lesions particularly involving the feet, even in immunocompetent adults. LEARNING POINTS: Kaposi's sarcoma can mimic benign skin lesions, making it essential for providers to maintain a high index of suspicion in cases of atypical, recurrent, or rapidly evolving lesions.Atypical features and diagnostic uncertainty should prompt escalation to biopsy and pathology review, even in patients without known immunosuppression.