MUCIN CONTENT IN GALLBLADDERS WITH BROWN PIGMENT STONES OR COMBINATION STONES WITH A BROWN PERIPHERY

Background/Aims: Gallbladder mucus itself has been recognized to play an important role in gallstone development. Despite the diverse mechan isms of stone induction and the differences in stone composition, ther e is a quantitative increase in the epithelial mucus production period before stone formation. As brown pigment stones are found frequently in gallstone disease, we conducted a study on gallbladders with brown pigment stones or combination stones with a brown periphery to evaluat e the mucin content in the gallbladder epithelium in comparison to gal lbladders with cholesterol stones and those without stones. Methods: G allbladder specimens were fixed in 10% formalin immediately after chol ecystectomy and then embedded in paraffin. The specimens were sectione d for periodic acid-Schiff-alcian blue (PAS-AB, pH 2.5) double stain t o evaluate the intra-epithelial mucin content. The PAS-AB index was ca lculated as a proportion of the PAS-AB-positive mucin area to the tota l epithelial area, using a computerized image analyzer. Results: Evalu ation of the PAS-AB index on the lining epithelia of gallbladders show ed that it was 32.43 +/- 9.96% in gallbladders with brown stones, whic h is significantly (p < 0.001) higher than in gallbladders with choles terol stones (15.63 +/- 6.75%) and gallbladders without stones (9.55 /- 4.77%). Conclusion: The results show that gallbladders with brown s tones contain more abundant mucin than gallbladders with cholesterol s tones or those without stones. They also suggest that the gallbladder epithelium per se might play a more important role in stone formation in those with brown stones than in those with cholesterol stones.