EDC with pathologic correlation. (a) Transabdominal US image
at the level of the inferior margin of the liver (L)
shows the gut signature sign (also known as the double-wall or
five-layer sign) of the EDC wall. The multilayered alternating echogenic
appearance resembles normal bowel, with similar innermost hyperechoic
mucosa, hypoechoic muscularis mucosa, hyperechoic submucosa, hypoechoic
muscularis propia, and outermost hyperechoic serosa (bracket) of the
duplicated bowel wall of the EDC (*). This cyst served as the
lead point for an intussusception (shown in
Fig E5) and was resected.
(b) Photograph of a cut gross specimen shows the common
wall (arrowheads) of the EDC and subjacent bowel loop.
Lumen = small-bowel lumen. (c)
Low-power photomicrograph (H-E stain) of an EDC shows the shared wall
(*) between the small-bowel loop and EDC. Arrowheads =
mucosae.