Granuloma

Rokitansky-Aschoff sinuses:
Rokitansky-Aschoff sinuses represent herniation of the mucosa into and sometimes through the gallbladder wall.They are not of themselves considered abnormal, but they can be associated with cholecystitis.They form as a result of increased pressure in the gallbladder and recurrent damage to the wall of the gallbladder.Black pigment gallstones can form in Rokitansky–Aschoff sinuses of the gallbladder after the fourth to fifth decades of life in absence of the typical risk factors for bilirubin suprasaturation of bile. Hence, they are associated with gallstones.Cases of gall bladder cancer have also been reported to arise from Rokitansky–Aschoff sinuses.