Metastatic Kaposi's Sarcoma with Perirectal Involvement Diagnosed with Endoscopic Ultrasound-Guided EchoBrush Cytology Sampling

AIDS-related Kaposi's sarcoma (KS) is a low-grade vascular tumor that occurs in association with human herpesvirus 8 infection. Here we report the case of a 21-year-old male with recently diagnosed cutaneous KS who presented with rectal bleeding and anal pruritus. Initial endoscopic evaluation was nondiagnostic. CT imaging showed diffuse lymphadenopathy including perirectal involvement which was suspicious for metastatic KS. Echoendoscopy with needle biopsies and EchoBrush sampling of the lymph nodes revealed spindle cells confirming metastatic KS. Treatment was initiated with liposomal doxorubicin resulting in rapid improvement of the skin lesions. After treatment completion, repeat CT imaging showed improved lymphadenopathy. No further rectal bleeding or perianal pruritus was reported. Although the EchoBrush has previously been used to aid in the diagnosis of pancreatic lesions, this report describes a novel use of EchoBrush to diagnose KS from perirectal lymph nodes.