Kaposi's sarcoma of the rectum

A 40-year old male patient, professor, without previous relevant medical history searched medical assistance for rectal bleeding for the previous two weeks associated with proctalgia. He denied perianal pruritus or secretions or other major complaints. At physical examination he presented with an excellent general state, without skin lesions or palpable adenopathies. Rectal digital examination detected an irregular and painful rectal mass with rough consistence. Laboratory data: leucocytes 5.800 μL (58.2% neutrophils; 32.3% lymphocytes), haemoglobin 13.7 g/dL, platelets 247.000/ μL, creatinine 1.01 mg/dL, blood-urea nitrogen 20 mg/dL, C-reactive protein 44.8 mg/dL. A colonoscopy was performed, revealing a polypoid vinous lesion occupying approximately 2/3 of the luminal circumference (Figs. 1 and 2). A macrobiopsy with a polipectomy snare was obtained. Histological analysis revealed multiple small blood vessels delimited by spindle cells displayed in a swirl pattern with areas of bleeding and hemosiderin deposits. Immunohistochemical staining was positive for vimentin, CD 31 and CD 34 (Fig. 3). These findings were highly suggestive of Kaposi’s sarcoma afflicting the rectum. HIV serologies were positive. The subsequent investigation for other Kaposi’s lesions was negative. Kaposi’s sarcoma of the rectum