label: Silhouette sign
label_lc: silhouette sign
description: "The silhouette sign is the absence of depiction of an anatomic soft-tissue border. It is caused by consolidation and/or atelectasis of the adjacent lung, by a large mass, or by contiguous pleural fluid. The silhouette sign results from the juxtaposition of structures of similar radiographic attenuation. The sign actually refers to the absence of a silhouette."