Polypoid lesions of the gallbladder: diagnosis and indications for surgery.

One hundred and eighty-two patients with an ultrasonographic and/or pathological diagnosis of polypoid lesions of the gallbladder (PLG) were reviewed to determine the reliability of ultrasonography in the diagnosis of PLG and the indications for operation in this disease. Of the 182 patients operated on, PLG were demonstrated by the gross appearance of the resected gallbladder in 172. Histologically benign lesions were present in 159 gallbladders and malignant lesions in 13. Cholesterol polyps accounted for most benign PLG. The sensitivity of ultrasonography in detecting PLG was 90.1 per cent, significantly higher than that of oral cholecystography, computed tomography or endoscopic retrograde cholangiopancreatography (P less than 0.01). The specificity of ultrasonography in the diagnosis of PLG was 93.9 per cent. Therefore, ultrasonography is a highly sensitive method for investigating PLG, and the preoperative diagnosis of PLG in this unit has now become entirely dependent on this technique. The size and number of PLG, the presence of gallstones and the patient's age all correlate with the nature of PLG, and these features are helpful in differentiating malignant from benign lesions before operation. Surgical treatment is indicated when PLG exceed 1.0 cm in diameter, when PLG are single in number, when PLG are associated with gallstones, when patients with PLG are over the age of 50 years, or when clinical symptoms of PLG are apparent.