Dropped gallstones mimicking peritoneal metastasis: A case report

Abstract

Dropped gallstones is a rare complication after a cholecystectomy. Computed tomography is the modality of choice for diagnosis. Dropped gallstones can be a fortuitous discovery in an asymptomatic patient but it is usually revealed when a complication occurs, most commonly through an abscess. Our case presents a dropped gallstone found during a routine check-up in a patient with a history of small bowel cancer. We will discuss differential diagnosis with others calcified peritoneal nodular patterns, particularly peritoneal carcinomatosis. We will recall the multimodality imaging findings of dropped gallstone and, based on literature, we will review the different sources of calcified peritoneal nodular pattern. The treatment of gallstone drop consequences depends on the clinical aspect.

No stone left unturned: a case of malignant mimicry

“…However, cholesterol‐based stones (which are non‐calcified) may not be visible on CT until long‐standing, chronic, tissue reaction has occurred 2,4 . MRI and ultrasound can be used to corroborate the diagnosis, but are also often difficult to interpret 1,3,4,5 . Similarly, FDG‐PET CT frequently shows low avidity of retained gallstones, which can also be the case with peritoneal carcinomatosis 9 .…”

“…Consequently, when calcified peritoneal nodules are discovered, peritoneal metastases from appendiceal, colorectal, gastric or ovarian cancer should be ruled out 1,2 . Accordingly, there are rare reports of retained gallstones discovered on diagnostic laparoscopy after suspicion of peritoneal carcinomatosis 3,5,6,7 . Dropped gallstones have the potential to slowly erode through tissue planes and deposit in the retroperitoneum, peritoneum of the abdominal wall, or even the pleural cavity 4 .…”

“…2,4 MRI and ultrasound can be used to corroborate the diagnosis, but are also often difficult to interpret. 1,3,4,5 Similarly, FDG-PET CT frequently shows low avidity of retained gallstones, which can also be the case with peritoneal carcinomatosis. 9 Consequently, when calcified peritoneal nodules are discovered, peritoneal metastases from appendiceal, colorectal, gastric or ovarian cancer should be ruled out.…”

“…1,2 Accordingly, there are rare reports of retained gallstones discovered on diagnostic laparoscopy after suspicion of peritoneal carcinomatosis. 3,5,6,7 Dropped gallstones have the potential to slowly erode through tissue planes and deposit in the retroperitoneum, peritoneum of the abdominal wall, or even the pleural cavity. 4 They may elicit an inflammatory response like peritoneal metastases leading to diagnostic uncertainty.…”

“…4 CT occasionally demonstrates high-attenuation calcifications, centred around the gallbladder fossa. 3 However, cholesterol-based stones (which are non-calcified) may not be visible on CT until long-standing, chronic, tissue reaction has occurred. 2,4 MRI and ultrasound can be used to corroborate the diagnosis, but are also often difficult to interpret.…”