Silhouette sign of chest X-ray – a rescue sign of a lung carcinoma that almost missed

Lung carcinoma typically presents with haemoptysis and constitutional symptoms on a background history of chronic cigarette smoking. A chest X-ray can pick up these lesions in view of its radio-opacity and nodular appearances that are manifested in more than 90% of cases.1 However it can be mistakenly interpreted as normal if it is obscured by heart shadow. Nevertheless, loss of a specific contour can help determine the presence position of a disease process. This phenomenon is known as the silhouette sig