68 Ga-FAPI-04 Versus 18 F-FDG PET/CT in a Case of Peutz-Jeghers Syndrome.

Peutz-Jeghers syndrome is a rare inherited hamartomatous polyposis syndrome. We describe 68 Ga-FAPI-04 and 18 F-FDG PET/CT findings in a case of Peutz-Jeghers syndrome with primary duodenal clear cell sarcoma, peritoneal metastases, and multiple intestinal polyps varying in size. The duodenal tumor and its metastases showed increased FDG and FAPI uptake. The peritoneal metastases were delineated more clearly on FAPI PET/CT compared with FDG PET/CT. More interestingly, the intestinal polyps showed increased FDG uptake and no FAPI uptake.