Editor,—The paper by Moriguchi et al(Gut 1996; 39: 860–2) raises a number of questions. The authors state that this is the first study to describe the natural history of these lesions, but their solitary conclusion, that most polypoid lesions of the gall bladder detected by ultrasonography are benign, is not new. Indeed, they seem to underestimate the risk of malignancy compared with other larger series.

Yang et al 1 studied 182 patients who underwent cholecystectomy and who had an ultrasonographic or pathological diagnosis of polypoid lesions of the gall bladder. There were 10 false positive ultrasound diagnoses. All the lesions …