Pulmonary mass with a classical sign on computed tomography scan

CT-guided core biopsy from the lesion was performed that on histopathological examination showed pattern characteristic of bronchoalveolar cell carcinoma [Figure 3]. Answers Answer 1: CT angiogram sign (seen as prominent pulmonary vasculature within pulmonary mass) Answer 2: CT angiogram sign represents the enhancement of unaffected pulmonary vessels coursing through low-attenuating consolidated lung parenchyma (filled with mucus and fluid) relative to chest wall musculature. [1] Subsequently, it was observed that the sign was not specific for bronchoalveolar carcinoma only and may be seen in both malignant and nonmalignant conditions such as primary pulmonary lymphoma, postobstruction pneumonias and pneumonitis without central obstruction, lipoid pneumonias, passive atelectasis, pulmonary edema, and metastasis from gastrointestinal carcinoma.