Apple core lesion on barium enema

What it is

The shoulder ring sign, also called an apple core lesion, is what a double contrast barium enema shows when a lesion runs all the way round the bowel. The example given is an apple-core lesion surrounding the lumen of the descending colon.

Described from the film itself: double-contrast barium enema demonstrates a focal narrowing in the sigmoid colon; it has rolled, heaped up shoulders and results in a severe stenosis; features are typical of the so-called apple-core stenosis. The remainder of the imaged colon appears normal in caliber, and lined by normal mucosa - which is part of the sign, because the lesion is focal and what lies on either side of it is not.

How it is diagnosed

A shoulder ring sign, or apple core lesion, in barium enema is suggestive of malignancy. It is cancer of the colon as seen on barium enema, so the finding does not stand alone as a shape to name but as the thing that turns the work toward cancer.