Natural history of polypoid lesions in the gall bladder

Although polypoid lesions of the gall bladder are frequently observed in asymptomatic subjects, the natural history of these lesions has never been studied using ultrasonography.

The natural history of polypoid lesions of the gall bladder was investigated using ultrasonography.

Among 4343 patients who presented to the outpatient clinic of Tsuchiura Kyodo General Hospital in 1988, 111 subjects were diagnosed as having polypoid lesions of the gall bladder by ultrasonography. Among these patients, two had gall bladder carcinoma. The remaining 109 subjects (58 female; age: median 54, range 25-89) were enrolled in this study.

The subjects were followed up by ultrasonography once or twice a year until 1994.

Four patients received cholecystectomy and two patients died of other causes during the observation period. In one patient, gall bladder carcinoma was found, but its location was different from that of the pre-existing polyp. The size of the lesions did not change in 88.3% of the other 130 patients during this period, even among those in whom the initial size of the lesion exceeded 10 mm. There was no apparent correlation between the change in the diameter of the polypoid lesions and patients' sex or age.

Most polypoid lesions of the gall bladder detected by ultrasonography are benign.