Composition of gallstones in Coimbatore District of Tamil Nadu State

Gallstones in northern India are predominantly of the cholesterol type; such information on gallstones in southern India is scant.

To analyze the composition of gallstones from patients residing in Coimbatore District in Tamil Nadu State.

The stones were classified using the Bernhoft criteria and was correlated with the morphological characteristics.

Of the 105 gallstones analyzed, 67 (63.8%) were of the pigment variety and 36 (34.8%) of the intermediate/mixed type. There were only two cholesterol stones. The mean proportions of cholesterol, bilirubin and calcium in the pigment and intermediate stones were 7.1%, 26.1% and 7.8% and 30.2%, 18.4% and 6.3%, respectively. The mean proportion of bilirubin in the pigment stones was higher than in the intermediate type. Morphologically, pigment stones were black in 55% and amorphous in 63%; the intermediate stones were hard in 50% and of variegated color ranging from yellow to ivory white in 61%; both cholesterol stones were multiple, hard and brown.

There is a predominance of pigment and intermediate gallstones (98%) in this district. These stones have reduced cholesterol and an increase in bilirubin and calcium proportions.