An official website of the United States government
Here's how you know
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Three distinct mucosal patterns observed under magnification (115×) after spraying indigo carmine: ridge villous (A), circular (B), and irregular/distorted (C).