Kaposi's sarcoma of the lung in AIDS: radiologic-pathologic analysis

Kaposi's sarcoma in patients with AIDS involves the lung more often than it does in the African form of the neoplasm. This article describes the radiographic and histologic features in nine cases of pulmonary Kaposi's sarcoma, uncomplicated by infection, and reviews the radiographic descriptions of 22 similar cases from the literature. Pulmonary parenchymal disease in reported cases and in this series was usually diffuse. Three cases had localized disease. In one of these cases, the localized disease was segmental while in the other two cases, the disease involved a single entire lobe. Hilar adenopathy was noted in three of 22 cases in the literature and in three of nine cases in this series. Pleural effusion was noted in eight of 22 cases in the literature and in three of the nine cases in the current series. Histologic examination of the lung from patients whose radiographs showed predominantly nodular lesions revealed a prevalence of nodules composed of prominent spindle cells with atypical mitotic figures in the nuclei. However, patients having a linear pattern on radiographs showed predominantly thickened interstitium characterized by invasive angiomatous proliferation of irregular slitlike vessels with atypical endothelial cells. The results of this study indicate that in AIDS patients with Kaposi's sarcoma of the lungs, uncomplicated by infection, two distinctive radiographic appearances of the lesions occur and that these two apparently different lesions can be explained by two types of histologic findings that correspond well with the radiographic features.