Muscle in mucosal folds of gallbladders with cholecystitis

This study reports observations made on the occurrence of smooth muscle in the mucosal folds of gallbladders in various stages of cholecystitis. Tissue from 228 gallbladders was classified into one of the three defined grades of cholecystitis: chronic mild, chronic advanced and acute, using standardized histopathological grading criteria. Microscopic examination revealed a reduction in the number, magnitude and overall configuration of the mucosal folds in chronic advanced and acute cholecystitis. In addition there appeared to be a respective decrease in frequency with which smooth muscle appeared within the folds. Muscle bundles were observed only within the primary folds and not in the higher secondary folds. Of the 228 gallbladders resected, 35 specimens contained measurable amounts of smooth muscle within their mucosal folds. Of these 35, thirty (86%) exhibited chronic mild disease, a state which more closely resembles normal tissue, and five (14%) exhibited chronic advanced disease. The basic mucosal pattern in chronic mild cholecystitis would then be expected to exhibit more consistency than would the more advanced states. The inherent action of the lamina propria determines to a great extent the number, position and morphology of the mucosal folds. Occasional muscle loops also appear to be responsible for the formation of a number of folds. The formation of these folds is for the most part a passive process and related to the pathological status of the lamina propria, muscle layer and the mucosal layer.