Radiology Spotters Collection

???? Get a Head Start To Your Radiology Career ↗️

Dropped Gall Stones | Radiology Board Review Case

Subscribe RadioGyan YouTube channel

Dropped Gall Stones and Differentials of Peritoneal Deposits | Radiology Board Review Case

Incidence and pathophysiology

  • Spillage of gall stones in the peritoneal cavity causes “dropped” gall stones or retained gall stones.
  • These are common with laparoscopic cholecystectomies, reported in up to 7 percent cases.
  • Can act as an inflammatory nidus, especially pigment gall stones.
  • Can migrate and lie outside the peritoneal cavity.
  • Complications:
    • Abscesses – Most commonly at the abdominal port sites and the perihepatic spaces.
    • Fistulas
    • Others.

Imaging features

  • Location: Perihepatic spaces and pelvis
  • CT – Small iso to hypodense nodular lesions. Stones with calcium content will appear hyperdense.
  • MRI – Non-enhancing T1 hyperintense foci.
  • Look for interval stability and history of laproscopic cholecystectomy.
  • Often confused with peritoneal deposits as in the case illustrated above.
  • Differentials include peritoneal metastasis, colonic diverticula, dropped appendicolith and peritoneal loose bodies AKA “peritoneal mice” (chronic torsion and auto-amputation of epiploic appendages causes these benign soft tissue nodules in the peritoneal cavity).


Drainage of abscess and removal of all gall-stones. This can be usually be achieved by percutaneous drainage, if unsuccessful laparoscopy can be performed.

Differentials diagnosis of peritoneal nodules

  • Peritoneal carcinomatosis
  • Primary peritoneal mesothelioma
  • Peritoneal tuberculosis
  • Lymphoma
  • Dropped gall-stones
  • Splenosis
  • Primary peritoneal mesothelioma

Reference and further reading

To attend live, join our Telegram group to get regular updates for these webinars:

More Radiology videos:

Share this with your friends and colleagues on social media!

About the Author

Dr. Amar Udare, MD, DNB

Dr Amar Udare Dr. Amar Udare is a board-certified radiologist. He is a clinical assistant professor at the University of Calgary. He has a passion for teaching (#FOAMrad and #FOAMed) and has been a semi-finalist for the 2018 and 2020 Aunt-Minnie Most effective Radiology Educator Awards. He has authored multiple peer-reviewed publications which can be accessed on PubMed and Google Scholar.


Leave a Comment

Your email address will not be published. Required fields are marked *