Atypical Presentation of Kaposi Sarcoma

CASE REPORT A 38-year-old man was admitted with Pneumocystis jirovecii pneumonia and newly diagnosed AIDS. Seven months earlier, he had surgery for perianal abscess and fistula. At admission, CD4+ count was 12/µL and HIV viral load 70,700 copies/mL. He received cotrimoxazole and started antiretroviral therapy (ART) (bictegravir/emtricitabine/tenofovir alafenamide). Three weeks later, he returned with fever and respiratory symptoms. Oral violaceous lesions were diagnosed as Kaposi sarcoma (KS). Chest computed tomography showed new mediastinal and retroperitoneal lymphadenopathy and irregular pulmonary consolidations with ground-glass halo, suggestive of pulmonary KS. Colonoscopy revealed a distal rectal lesion (Figure 1), with histopathology confirming vascular proliferation and human herpesvirus 8 positivity, consistent with KS. No cutaneous lesions were observed. Given clinical stability, viral load reduction (39 copies/mL), and CD4 count improvement (56/µL), outpatient follow-up and surveillance were adopted.Figure 1.: Endoscopic image in retroflexion view of a 20 mm polypoid lesion with a violaceous appearance in the distal rectum.KS is a vascular neoplasm caused by human herpesvirus 8, typically occurring in immunodeficiency states.1,2 Although KS classically presents as a cutaneous disease, it can involve virtually any visceral organ, posing significant diagnostic challenges for clinicians.3,4 Gastrointestinal involvement is notably more common in patients without cutaneous lesions compared with those with skin manifestations.2,3 However, most patients with gastrointestinal KS are asymptomatic or present with nonspecific symptoms, and the diagnosis is often made incidentally during endoscopy or at autopsy. In the present case, extensive visceral KS involvement developed after initiation of ART, likely representing KS-associated immune reconstitution inflammatory syndrome (KS-IRIS).5 Although rare, KS-IRIS is a serious complication in severely immunosuppressed patients. No standardized recommendations exist for its diagnosis or management; however, continuation of ART is generally advised. DISCLOSURES Author contributions: A. Guimarães conceived and designed the study (conceptualization, methodology). R. Azevedo; S. Lopes and J. Soares contributed to the critical review of the manuscript (writing—review & editing). All authors read and approved the final version of the manuscript. Financial disclosure: None to report. Informed consent was obtained for this case report.