This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.
Summary
DescriptionAnorectal mucosa with hemorrhoid.jpg
English: Histopathology at the pectinate line, showing rectal mucosa (at left in image) and anoderm (right) with a thrombosed hemorrhoid (slightly left of center in image). H&E stain.
The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
http://creativecommons.org/publicdomain/zero/1.0/deed.enCC0Creative Commons Zero, Public Domain Dedicationfalsefalse