Kaposi's Sarcoma Presenting as a Bulky Tumor Mass of the Colon

Abstract

t m A homosexual man presented with lower abdominal pain several times a day and diarrhea of -months duration. He was diagnosed with human immunoeficiency virus (HIV) infection 2 years before presentation and ad not received highly active antiretroviral therapy (HAART). is CD4 count was 11 cells/ L, and his HIV RNA viral load was .3 105 copies/mL. He had slight anemia, with hemoglobin of 1.4 g/dL. On physical examination we found a firm purple odule throughout the body. Stool examinations for ova, parsites, bacteria, and mycobacteria were negative. Two tests for ecal occult blood were positive. Colonoscopy revealed the rectum and sigmoid colon were rossly normal. However, the descending colon contained a ulky mass surrounding the entire colon where the epithelium ad a deep red color (Figure A) after indigo carmine dye (Figure B). There was a stricture of the colon through which the endoscopic fiber barely passed (Figure B). Computed tomography scan on the same site also revealed a massive lesion. Hematoxylin-eosin staining of biopsy specimen showed moderate chronic inflammation and proliferation of spindle cells with vascular slits and hemorrhage, consistent with Kaposi’s sarcoma (KS) (Figure C). The viral load of KS-associated herpesvirus in the blood was high at 7 104 copies/mL. Systemic treatment with HAART and pegylated liposomal doxorubicin was started. After 2 months of treatment, his symptoms had improved. A repeat colonoscopy revealed that the lesion subsequently became smaller. KS is the most common neoplasm in patients with acquired immune deficiency syndrome (AIDS).1 KS is especially common among homosexual patients with AIDS and those with particularly low CD4 counts.1,2 In KS, the gastrointestinal tract is the hird most affected site after the skin and lymph nodes. Most astrointestinal lesions might be asymptomatic, but advanced lesions might cause bleeding, diarrhea, and abdominal pain and require immediate treatment.1 In this case, there was a risk of bstruction and hemorrhage of the colon. On endoscopy, gastrointestinal KS is characterized by feaures such as multiple submucosal nodules with deeply red ucosa.3 Lesions might also have features of polypoid nodules, have maculopapular appearance, manifest as mass lesions, and rarely present bulky tumor like this case.3 The prognosis of HIV infection has improved since the introduction of HAART. Furthermore, early diagnosis of KS in the colon can improve prognosis and quality of life. Endoscopy should not be hesitated on for patients with abdominal symptoms, especially those with particularly low CD4 counts who are homosexual.