INTRODUCTION: Kaposi’s sarcoma (KS), an angioproliferative tumor, mainly involves mucocutaneous tissues. Extracutaneous spread to visceral organs including the lung can occur in acquired immunodeficiency syndrome (AIDS)-associated KS; however, pulmonary KS in the absence of mucocutaneous involvement is rare. Few cases of KS-associated immune reconstitution inflammatory syndrome (IRIS) have been reported. We report a case of probable KS-associated IRIS in a patient with AIDS who developed progressive respiratory failure one month after initiation of highly active antiretroviral therapy (HAART). At autopsy he was found to have pulmonary KS in the absence of mucocutaneous lesions.
CASE PRESENTATION: A 25 year-old man with AIDS presented to the emergency department with three days of dyspnea, nonproductive cough, hemoptysis, fevers and pleurisy. His CD4 count two months prior was 40 with a viral load of 403,000. He had started HAART one month prior to presentation. Physical examination revealed a non-toxic young male in mild respiratory distress. Notable findings were pulse 106, respirations 22, temperature 101.4, pulse oximetry 98%, and bibasilar crackles. He had no oral mucosal or skin lesions. Initial laboratory values included a white blood cell count of 5.1, platelets 31,000, CD4 of 170, and a viral load of 1500. Chest x-ray showed diffuse fine reticular interstitial opacities. CT scan revealed diffuse septal thickening, lobular and somewhat focal ground glass opacities, some nodular in appearance. Several of the nodular densities were surrounded by ground glass opacities. The differential diagnosis included alveolar hemorrhage, Pneumocystis jirovecii, bacterial, viral and other fungal infections. Bronchoscopy did not reveal any endobronchial lesions but the lavage fluid was mildly bloody. The patient was empirically treated for typical and opportunistic infections. Over the course of 2-3 weeks, he clinically deteriorated with worsening hypoxemia. Cultures remained negative. Repeat bronchoscopy again revealed no lesions or infection. He developed massive hemoptysis with subsequent respiratory failure and rapidly progressive shock with multi-system organ failure. At autopsy, gross examination revealed poorly demarcated pulmonary nodules. Microscopic examination of these nodules revealed an angiocentric pattern of spindle shaped tumor cells, proliferating endothelial cells and fibroblasts consistent with pulmonary KS.
DISCUSSIONS: KS remains the most common AIDS-associated cancer and may present with mucocutaneous lesions and visceral involvement. The clinical presentation of intrathoracic KS is nonspecific and may be indistinguishable from pneumonia. Readily identifiable endobronchial lesions are noted in 50%. Pulmonary KS in the absence of mucocutaneous involvement is rare however, ranging from 0-15% cases. Radiographic findings include peri-bronchovascular reticulonodular opacities, septal line thickening, consolidation and pleural effusions. Pulmonary KS carries a poor prognosis with a median survival of 2-10 months. Treatment is often palliative. Combination chemotherapy affords response rates of 30-50%. Radiation therapy benefits are short lived. HAART reduces the risk of developing KS and decreases growth rate of pre-existing KS and may improve median survival. KS-associated IRIS has been rarely reported. It usually occurs within two months of initiation of HAART and is characterized by the development of an inflammatory reaction with both progression and development of KS lesions. CT findings are similar to typical AIDS-related KS.
CONCLUSION: KS-associated IRIS should be considered in AIDS patients presenting with progressive respiratory abnormalities within 1-2 months of HAART initiation, even in the absence of mucocutaneous lesions or prior known disease. The clinical presentation may mimic infection. Radiographic findings include reticulonodular opacities, septal line thickening, consolidation, and pleural effusions. The course may be rapidly progressive and fatal.
DISCLOSURE: Rabih Halabi, No Financial Disclosure Information; No Product/Research Disclosure Information