Background: Definitive criteria for choosing the most appropriate treatment for each type of polypoid lesion of the gallbladder (PLG) have yet to be established.
Methods: The shapes, sizes, echo patterns, and echogenicities of PLGs that had been evaluated by means of ultrasonography in 72 patients who had undergone resective surgery were analyzed retrospectively to elucidate the ultrasonic characteristics of polypoid cancers and to establish criteria for selecting the most suitable treatment such as laparoscopic cholecystectomy for each type of PLG.
Results: Histologic examinations showed cholesterol polyps in 47 patients, adenomas in 8, cancers in 16, and an inflammatory polyp in 1. The diameters of 61% of the benign PLGs were less than 10 mm, whereas those of 88% of the cancers were more than 10 mm; 80% of the former were pedunculated and 56% of the latter were sessile. Seven of eight early-stage cancers had diameters less than 18 mm, whereas those of all eight more advanced cancers were greater than 18 mm. Five of the eight early-stage cancers were pedunculated, and six of the eight more advanced cancers were sessile. Cholecystectomy with or without full-thickness dissection were main surgical procedures used to resect benign PLGs and early-stage cancers, whereas cholecystectomy with partial liver resection was used for more advanced cancers. Laparoscopic cholecystectomy was performed in the recent 34 patients, four of whom had early-stage cancers.
Conclusions: A PLG with a diameter of less than 18 mm is a potential early-stage cancer and therefore can be resected by laparoscopic cholecystectomy with full-thickness dissection. However, when cancer invades the subserosal layer or beyond, a second-look operation is necessary. A PLG with a diameter of greater than 18 mm may be an advanced cancer and should be removed by using cholecystectomy with partial liver resection or a more extended procedure with lymph node dissection.