Sahota, R.

Abstract Introduction Pulmonary Kaposi Sarcoma (KS) is a rare manifestation of human immunodeficiency virus (HIV) infection, predominantly seen in immunocompromised patients and infrequently in the era of antiretroviral therapy (ART). KS is a mesenchymal neoplasm arising from blood and lymphatic vessel endothelial cells, primarily affecting homosexual or bisexual men with HIV. Diagnosis typically relies on a combination of clinical evaluation, radiographic imaging, and histopathological confirmation via biopsy. This case underscores the importance of considering pulmonary KS in the differential diagnosis of acute respiratory failure in patients with advanced HIV, even with ART. Case presentation A 44-year-old male with newly diagnosed HIV/AIDS was admitted to the ICU for acute hypoxic respiratory distress. He had initially presented months prior with skin rashes, an HIV viral load of 1040, and a CD4 count of 148, at which time antiretroviral therapy (Biktarvy) was initiated. A chest CT scan revealed diffuse bronchial wall thickening, ground-glass opacities, interlobular septal thickening in a perihilar and upper lung predominant distribution, and bilateral pleural effusions. Pleural fluid analysis confirmed an exudative profile, with worsening hemorrhagic effusions suggestive of visceral Kaposi sarcoma. Bronchoscopy indicated submucosal changes, especially in the left upper lobe and proximal main stems. Skin biopsy, fine-needle aspiration of an axillary lymph node, and a left upper lobe lung biopsy confirmed Kaposi sarcoma. The biopsy showed elevated EBV-positive cells, HHV8-positive sarcoma cells, CMV-negative status, and mixed T and B cells (CD3 and CD20). Lung immunohistochemistry indicated neoplastic cells positive for FLI1, CD31, and patchy HHV8 staining, but negative for AE1/AE3. With a diagnosis of Kaposi sarcoma involving pleuropulmonary, cutaneous, visceral, and lymph node regions, the patient was started on systemic chemotherapy with doxorubicin. Unfortunately, KS had spread signficantly and patient was made comfort care as he was having respiratory failure despite on mechanical ventilator. Discussion Before the advent of antiretroviral therapy (ART), Kaposi's sarcoma carried a poor prognosis, with pulmonary KS survival averaging 2-10 months. ART alone is generally sufficient for asymptomatic patients, often leading to lesion regression and forming the foundation of HIV-associated KS management. For symptomatic or progressive cases, systemic chemotherapy—typically pegylated liposomal doxorubicin—is recommended, as anthracyclines offer effective, lower-toxicity treatment. Paclitaxel may be used in patients unresponsive to anthracyclines. Although less common for KS, localized radiation therapy can provide symptomatic relief in cases of airway obstruction, hemoptysis, or pleuritic chest pain.