Gastrointestinal Kaposi sarcoma (GI-KS) is the most common extra-cutaneous site of KS in HIV/AIDS, and the majority (75%) of affected patients are asymptomatic. GI-KS rarely occurs in the absence of cutaneous lesions. Opportunistic GI infections in HIV/AIDS and GI-KS can present with similar symptoms especially diarrhea, creating a diagnostic challenge. We present a 46-year-old homosexual male with a medical history of HIV/AIDS and neurosyphilis, who presented with 2 weeks of nonbloody diarrhea and abdominal discomfort. He was initially worked up for infectious diarrhea, initiated on highly active anti-retroviral (HAART) and supportively managed with rehydration therapy and analgesia. However, his clinical symptoms did not improve, necessitating abdomen/pelvic CT scan which revealed extensive recto-sigmoid colon thickening and pelvic lymphadenopathy. Due to a high suspicion of malignancy, diagnostic endoscopy and biopsy were done which showed colonic KS. He was treated with intravenous pegylated doxorubicin in addition to HAART which evidently resulted in significant clinical and radiological improvement. The diagnosis of GI-KS could be challenging in the presence of overlapping features with opportunistic GI infections and the absence of cutaneous manifestations of KS because clinicians tend to focus more on infectious etiology. We suggest that clinicians should consider GI-KS in the differential diagnosis of patients with HIV/AIDS that present with diarrhea and other nonspecific abdominal symptoms. Early endoscopic evaluation with biopsy could help to ensure the timely diagnosis and management of GI-KS and ultimately improve outcomes.

中文翻译：

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HIV / AIDS中的下消化道卡波济肉瘤：诊断挑战。

胃肠道卡波西肉瘤（GI-KS）是HIV / AIDS中最常见的KS皮外部位，大多数（75％）受感染的患者无症状。GI-KS在没有皮肤病变的情况下很少发生。HIV / AIDS和GI-KS中的机会性GI感染可能会出现类似的症状，尤其是腹泻，这给诊断带来了挑战。我们介绍了一位具有HIV / AIDS和神经梅毒病史的46岁同性恋男性，其表现为2周的非血性腹泻和腹部不适。最初，他因感染性腹泻而接受治疗，开始使用高活性抗逆转录病毒药物（HAART），并通过补液疗法和镇痛进行支持性治疗。但是，他的临床症状并没有改善，必须进行腹部/骨盆CT扫描，以显示广泛的乙状结肠结肠增厚和骨盆淋巴结肿大。由于高度怀疑恶性肿瘤，因此进行了诊断性内窥镜检查和活检，显示为结肠KS。除HAART外，他还接受了静脉内聚乙二醇化阿霉素治疗，这明显改善了临床和放射学。在存在机会性GI感染的重叠特征且不存在KS的皮肤表现的情况下，GI-KS的诊断可能具有挑战性，因为临床医生倾向于更加关注传染病因。我们建议临床医生在出现腹泻和其他非特异性腹部症状的HIV / AIDS患者的鉴别诊断中应考虑使用GI-KS。