apical cap sign
apical cap signRadiology
1. A subtle blush or shadow on a plain chest film in the left lung apex caused by blood leaking from a traumatically ruptured aorta into the pleura, indicating a need for emergency aortic aortography and surgery.
2. Dunce cap sign A finding on a plain abdominal film in pheochromocytomas; the enlarged rounded tumor located in the adrenal medulla forms the 'head' and the triangular dunce cap representing the normal residual cortex which may be pushed superiorly.