<unk> , also entrapped epithelial crypts, are diverticula or pockets in the wall of the gallbladder.  They may be microscopic or macroscopic.
Histologically, they are outpouchings of gallbladder mucosa into the gallbladder muscle layer.
They are not of themselves considered abnormal, but they can be associated with cholecystitis.
Rokitansky-Aschoff sinuses
Olfactory foramina
Albrecht Kossel
Zygomatico-orbital foramina
Cusp of Carabelli
Rossmann fold
Swimmer's ear
Surfer's Ear