Dropped Gallstones Post Laparoscopic Cholecystectomy Mimicking Peritoneal Seeding: CT and Ultrasound Features

PURPOSE: The purpose of this work was to investigate the ultrasound (US) and CT features of dropped gallstones mimicking peritoneal seeding in patients after laparoscopic cholecystectomy (LCC). METHOD: We describe the US and CT features of dropped gallstones mimicking peritoneal seeding in eight patients who underwent LCC. We also conducted a retrospective study of consecutive LCC patients who subsequently had CT to determine the prevalence of this condition. RESULTS AND CONCLUSION: The density of dropped gallstones on CT ranged from hypodense to partially or completely calcified nodules. Some stones did not have visible surrounding reaction, whereas others showed an enhancing halo. All stones were echogenic and demonstrated shadowing on US. The stones were located mostly on the right side of the abdomen, and the majority were around the liver. The prevalence of dropped gallstones post laparoscopic cholecystectomy was 4.2%.